v3: generated placeholder thumbnails for pages with no preview image, and a fix for hotlink-protected ones

Thumbnails were failing in two different ways that both ended as an empty box.

Cloudflare hotlink protection answers a cross-site Referer with 403, so images
we had extracted correctly (dles.aukspot.com's og:image among them) never
rendered — every onError handler set display:none and swallowed it. The new
Thumbnail component loads with referrerPolicy="no-referrer", retries once
through /api/proxy-image for hosts that reject an empty referrer too, and only
then falls back to a placeholder.

Separately, the extraction cascade ended at the page's icon and then a guessed
/favicon.ico, so thumbnailUrl was almost never empty — just a 16x16 icon
cover-cropped into a 128x72 box. It now stops at real artwork, with faviconUrl
and accentColor (theme-color / msapplication-TileColor / mask-icon) as their own
fields. An absent thumbnailUrl finally means "no artwork", which is what makes
the placeholder possible: the site's own color mixed into the theme surface,
with its favicon centered on it, or its initial. Contrast holds for any
third-party color by construction rather than by luminance math, so nyt only
has to set --thumb-tint-strength to 0% to stay monochrome and geocities only
has to raise it. Missing accents fall back to a stable hostname-derived hue, so
rows saved before this get a tint with no backfill.

Migration 0011 reclassifies favicon-shaped thumbnailUrls on existing dumps.
The journal mosaic keeps its pull-quote and text fallbacks — the placeholder
appears there only to repair a broken image.

Also fixed: refresh silently overwrote good metadata with a failure stub, the
refresh button swallowed every error, refresh never broadcast the update,
extractBestIcon ranked SVG icons below 16x16 PNGs, and shared links with no
artwork carried no og:image at all.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

api/db/migrate.ts

@@ -9,6 +9,7 @@ import { up as up0007PasswordResetTokens } from "./migrations/0007_password_rese
 import { up as up0008ChatMessages } from "./migrations/0008_chat_messages.ts";
 import { up as up0009ChatReply } from "./migrations/0009_chat_reply.ts";
 import { up as up0010YoutubeEmbedStart } from "./migrations/0010_youtube_embed_start.ts";
+import { up as up0011SplitFaviconThumbnail } from "./migrations/0011_split_favicon_thumbnail.ts";
 
 interface Migration {
   name: string;
@@ -29,6 +30,7 @@ const MIGRATIONS: Migration[] = [
   { name: "0008_chat_messages", up: up0008ChatMessages },
   { name: "0009_chat_reply", up: up0009ChatReply },
   { name: "0010_youtube_embed_start", up: up0010YoutubeEmbedStart },
+  { name: "0011_split_favicon_thumbnail", up: up0011SplitFaviconThumbnail },
 ];
 
 export function runMigrations(db: DatabaseSync): void {

api/db/migrations/0011_split_favicon_thumbnail.ts

@@ -0,0 +1,74 @@
+import type { DatabaseSync } from "node:sqlite";
+
+// Moves favicon-shaped values out of `rich_content.thumbnailUrl` into the new
+// `faviconUrl` field.
+//
+// The extraction cascade used to end at the page's icon and then at a guessed
+// `${origin}/favicon.ico`, so `thumbnailUrl` was almost never empty — it just
+// held a 16×16 icon (or a 404) that the UI then cover-cropped into a 128×72
+// box. The cascade now stops at real artwork, and an absent `thumbnailUrl`
+// means "no artwork", which is what lets the frontend draw a placeholder.
+// This migration gives rows written before that change the same meaning.
+//
+// Purely local — it classifies the already-stored URL and makes no network
+// calls, so `accentColor` is deliberately not backfilled: the frontend derives
+// a stable hue from the hostname whenever one is missing, and
+// `refreshDumpMetadata` fetches the real color on demand.
+//
+// Idempotent: rows that already carry a `faviconUrl` are skipped, so a fresh
+// database built from schema.sql is a no-op.
+
+/**
+ * Whether a stored thumbnail URL is really a site icon.
+ *
+ * Deliberately loose. A false positive (a genuine cover image living under
+ * `/assets/icons/`) renders contained on a tinted field instead of
+ * cover-cropped — mildly wrong, never broken — so chasing them isn't worth the
+ * extra rules.
+ */
+function isIconUrl(raw: string): boolean {
+  let pathname: string;
+  try {
+    pathname = new URL(raw).pathname;
+  } catch {
+    return false;
+  }
+  return /favicon|apple-touch-icon|\/icons?\//i.test(pathname) ||
+    /\.(ico|svg)$/i.test(pathname);
+}
+
+export function up(db: DatabaseSync): void {
+  const rows = db.prepare(
+    `SELECT id, rich_content FROM dumps
+      WHERE kind = 'url' AND rich_content IS NOT NULL;`,
+  ).all() as { id: string; rich_content: string }[];
+
+  const update = db.prepare(
+    `UPDATE dumps SET rich_content = ? WHERE id = ?;`,
+  );
+
+  let patched = 0;
+  for (const row of rows) {
+    let rich: { thumbnailUrl?: string; faviconUrl?: string };
+    try {
+      rich = JSON.parse(row.rich_content);
+    } catch {
+      continue; // malformed payload — leave it untouched
+    }
+    if (rich.faviconUrl || !rich.thumbnailUrl) continue;
+    if (!isIconUrl(rich.thumbnailUrl)) continue;
+
+    const { thumbnailUrl: _dropped, ...rest } = rich;
+    update.run(
+      JSON.stringify({ ...rest, faviconUrl: rich.thumbnailUrl }),
+      row.id,
+    );
+    patched++;
+  }
+
+  if (patched > 0) {
+    console.log(
+      `[migrate] 0011: reclassified ${patched} favicon thumbnail(s)`,
+    );
+  }
+}

api/middleware/og.ts

@@ -11,6 +11,8 @@ interface OGMeta {
   title: string;
   description?: string;
   imageUrl?: string;
+  /** True only for real artwork — a square site icon must not claim a wide card. */
+  imageIsWide?: boolean;
   url: string;
 }
 
@@ -23,7 +25,9 @@ function escapeAttr(s: string): string {
 }
 
 function buildTags(meta: OGMeta): string {
-  const card = meta.imageUrl ? "summary_large_image" : "summary";
+  const card = meta.imageUrl && meta.imageIsWide
+    ? "summary_large_image"
+    : "summary";
   const tags = [
     `<title>${escapeAttr(meta.title)}</title>`,
     `<meta property="og:site_name" content="${OG_SITE_NAME}" />`,
@@ -105,10 +109,14 @@ export async function ogMiddleware(ctx: Context, next: Next) {
       } else if (dump.richContent?.thumbnailUrl) {
         imageUrl = dump.richContent.thumbnailUrl;
       }
+      // No artwork: fall back to our own site icon rather than the target's
+      // favicon, which is typically too small to survive a social card (and may
+      // be hotlink-protected).
       meta = {
         title: dump.title,
         description: dump.comment,
-        imageUrl,
+        imageUrl: imageUrl ?? `${origin}/apple-touch-icon.png`,
+        imageIsWide: !!imageUrl,
         url: pageUrl,
       };
     } catch { /* not found or private — serve default */ }
@@ -121,7 +129,7 @@ export async function ogMiddleware(ctx: Context, next: Next) {
       meta = {
         title: user.username,
         description: user.description,
-        imageUrl,
+        imageUrl: imageUrl ?? `${origin}/apple-touch-icon.png`,
         url: pageUrl,
       };
     } catch { /* not found */ }
@@ -135,7 +143,7 @@ export async function ogMiddleware(ctx: Context, next: Next) {
         meta = {
           title: playlist.title,
           description: playlist.description,
-          imageUrl,
+          imageUrl: imageUrl ?? `${origin}/apple-touch-icon.png`,
           url: pageUrl,
         };
       }

api/model/interfaces.ts

@@ -10,7 +10,16 @@ export interface RichContent {
   siteName?: string;
   title?: string;
   description?: string;
+  /**
+   * A real preview image (og:image, a large content image, a video still).
+   * Never a favicon — an absent value means "this page offers no artwork",
+   * which is what makes the generated placeholder possible.
+   */
   thumbnailUrl?: string;
+  /** The page's own icon, used as the placeholder's glyph. */
+  faviconUrl?: string;
+  /** The page's declared brand color, normalized to `#rrggbb`. */
+  accentColor?: string;
   videoId?: string;
   embedUrl?: string;
 }

api/services/dump-service.ts

@@ -13,7 +13,11 @@ import {
   dumpRowToApi,
   isDumpRow,
 } from "../model/db.ts";
-import { fetchRichContent, isValidHttpUrl } from "./rich-content-service.ts";
+import {
+  fetchRichContent,
+  isValidHttpUrl,
+  tryFetchRichContent,
+} from "./rich-content-service.ts";
 import {
   broadcastDumpDeleted,
   broadcastDumpUpdated,
@@ -596,7 +600,19 @@ export async function refreshDumpMetadata(dumpId: string): Promise<Dump> {
     );
   }
 
-  const richContent = await fetchRichContent(dump.url);
+  // A failed fetch yields a stub with no title and no thumbnail. Writing that
+  // over a dump that already has good metadata would silently destroy it and
+  // rename the dump to its bare hostname, so bail out instead — the caller
+  // surfaces the error and nothing is lost.
+  const { ok, content: richContent } = await tryFetchRichContent(dump.url);
+  if (!ok) {
+    throw new APIException(
+      APIErrorCode.SERVER_ERROR,
+      502,
+      "Could not reach the page to refresh its metadata",
+    );
+  }
+
   const title = richContent?.title ?? titleFromUrl(dump.url);
 
   const updatedDump: Dump = { ...dump, title, richContent };
@@ -605,6 +621,8 @@ export async function refreshDumpMetadata(dumpId: string): Promise<Dump> {
     `UPDATE dumps SET title = ?, rich_content = ? WHERE id = ?;`,
   ).run(row.title, row.rich_content, row.id);
 
+  if (!updatedDump.isPrivate) broadcastDumpUpdated(updatedDump);
+
   return updatedDump;
 }
 

api/services/providers/generic.ts

@@ -5,10 +5,13 @@ import {
   extractFirstContentImage,
   extractJsonLd,
   extractLargeImage,
+  extractMaskIconColor,
   extractMetaName,
   extractOgTag,
   extractPageTitle,
+  extractThemeColor,
   fetchWithTimeout,
+  normalizeCssColor,
 } from "../rich-content-service.ts";
 
 export const genericProvider: RichContentProvider = {
@@ -59,21 +62,37 @@ export const genericProvider: RichContentProvider = {
       ld.description ??
       extractMetaName(html, "description");
 
-    // Image: og:image (page-matched) → twitter:image → JSON-LD → large <img> → first content <img> → best icon → /favicon.ico
+    // Image: og:image (page-matched) → twitter:image → JSON-LD → large <img> →
+    // first content <img>. The chain deliberately stops there: a favicon is not
+    // artwork, and pretending otherwise means every art-less page gets a 16×16
+    // icon cover-cropped into a 128×72 box. No match here means "no artwork",
+    // and the frontend draws a generated placeholder instead.
     const thumbnailUrl = (useOg ? extractOgTag(html, "image") : undefined) ??
       extractMetaName(html, "twitter:image") ??
       ld.thumbnailUrl ??
       extractLargeImage(html, url) ??
-      extractFirstContentImage(html, url) ??
-      extractBestIcon(html, url) ??
+      extractFirstContentImage(html, url);
+
+    // Icon and brand color are independent facts about the page, so they're
+    // collected whether or not there's artwork. `/favicon.ico` is a guess; when
+    // it 404s the placeholder falls back to the site's initial.
+    const faviconUrl = extractBestIcon(html, url) ??
       `${new URL(url).origin}/favicon.ico`;
 
+    const accentColor = normalizeCssColor(
+      extractThemeColor(html) ??
+        extractMetaName(html, "msapplication-TileColor") ??
+        extractMaskIconColor(html),
+    );
+
     return {
       type: "generic",
       url,
       title,
       description,
       thumbnailUrl,
+      faviconUrl,
+      accentColor,
       siteName,
     };
   },

api/services/providers/self.ts

@@ -3,12 +3,20 @@ import type { RichContentProvider } from "../rich-content-service.ts";
 import { getDump } from "../dump-service.ts";
 import { getUserByUsername } from "../user-service.ts";
 import { getPlaylistById } from "../playlist-service.ts";
-import { PUBLIC_URL } from "../../config.ts";
+import { PUBLIC_URL, THEME_COLOR } from "../../config.ts";
 
 const DUMP_RE = /^\/dumps\/([^/]+)$/;
 const USER_RE = /^\/users\/([^/]+)$/;
 const PLAYLIST_RE = /^\/playlists\/([^/]+)$/;
 
+// Internal links carry gerbeur's own branding, so an art-less one still gets a
+// recognizable placeholder instead of a generic tint.
+const SELF_BRANDING = {
+  siteName: "gerbeur",
+  faviconUrl: `${PUBLIC_URL}/apple-touch-icon.png`,
+  accentColor: THEME_COLOR,
+} as const;
+
 export const selfProvider: RichContentProvider = {
   name: "self",
 
@@ -38,7 +46,7 @@ export const selfProvider: RichContentProvider = {
       return Promise.resolve({
         type: "generic",
         url,
-        siteName: "gerbeur",
+        ...SELF_BRANDING,
         title: dump.title,
         description: dump.comment,
         thumbnailUrl,
@@ -54,7 +62,7 @@ export const selfProvider: RichContentProvider = {
       return Promise.resolve({
         type: "generic",
         url,
-        siteName: "gerbeur",
+        ...SELF_BRANDING,
         title: user.username,
         description: user.description,
         thumbnailUrl,
@@ -70,7 +78,7 @@ export const selfProvider: RichContentProvider = {
       return Promise.resolve({
         type: "generic",
         url,
-        siteName: "gerbeur",
+        ...SELF_BRANDING,
         title: playlist.title,
         description: playlist.description,
         thumbnailUrl,

api/services/rich-content-service.ts

@@ -184,6 +184,117 @@ export function extractPageTitle(html: string): string | undefined {
   return match ? decodeHtmlEntities(match[1].trim()) : undefined;
 }
 
+// ── Brand color helpers ───────────────────────────────────────────────────────
+
+/**
+ * Find the page's `theme-color`.
+ *
+ * Sites routinely ship the tag twice, scoped by `media`, and often list the
+ * dark-scheme one first — so unlike `extractMetaName` this can't just take the
+ * first match. Prefer the unscoped tag, then the light-scheme one, then any.
+ */
+export function extractThemeColor(html: string): string | undefined {
+  const tagRe = /<meta\b[^>]*>/gi;
+  const contentRe = /\bcontent=(["'])([\s\S]*?)\1/i;
+  const mediaRe = /\bmedia=(["'])([\s\S]*?)\1/i;
+  let unscoped: string | undefined;
+  let light: string | undefined;
+  let any: string | undefined;
+
+  let m: RegExpExecArray | null;
+  while ((m = tagRe.exec(html)) !== null) {
+    const tag = m[0];
+    if (!/\bname=["']theme-color["']/i.test(tag)) continue;
+    const content = contentRe.exec(tag)?.[2];
+    if (!content) continue;
+    const media = mediaRe.exec(tag)?.[2];
+    if (!media) unscoped ??= content;
+    else if (/light/i.test(media)) light ??= content;
+    any ??= content;
+  }
+  return unscoped ?? light ?? any;
+}
+
+/** Extract the `color` of `<link rel="mask-icon">` (Safari pinned tabs). */
+export function extractMaskIconColor(html: string): string | undefined {
+  const linkRe = /<link[^>]+>/gi;
+  let m: RegExpExecArray | null;
+  while ((m = linkRe.exec(html)) !== null) {
+    const tag = m[0];
+    if (!/\brel=["'][^"']*mask-icon[^"']*["']/i.test(tag)) continue;
+    const color = /\bcolor=(["'])([\s\S]*?)\1/i.exec(tag)?.[2];
+    if (color) return color;
+  }
+  return undefined;
+}
+
+// The handful of named colors that actually show up in `theme-color`. The full
+// 148-name table isn't worth carrying for the long tail.
+const NAMED_COLORS: Record<string, string> = {
+  black: "#000000",
+  white: "#ffffff",
+  red: "#ff0000",
+  green: "#008000",
+  blue: "#0000ff",
+  yellow: "#ffff00",
+  orange: "#ffa500",
+  purple: "#800080",
+  gray: "#808080",
+  grey: "#808080",
+  silver: "#c0c0c0",
+  maroon: "#800000",
+  navy: "#000080",
+  teal: "#008080",
+  olive: "#808000",
+  lime: "#00ff00",
+  aqua: "#00ffff",
+  cyan: "#00ffff",
+  fuchsia: "#ff00ff",
+  magenta: "#ff00ff",
+};
+
+function clampByte(n: number): number {
+  return Math.max(0, Math.min(255, Math.round(n)));
+}
+
+/**
+ * Normalize a CSS color to canonical lowercase `#rrggbb`, or `undefined` when
+ * it isn't one of the forms sites actually use. Alpha is dropped — the color is
+ * only ever used as a tint over the app's own surface.
+ */
+export function normalizeCssColor(raw: string | undefined): string | undefined {
+  if (!raw) return undefined;
+  const value = raw.trim().toLowerCase();
+
+  const named = NAMED_COLORS[value];
+  if (named) return named;
+
+  const hex = /^#([0-9a-f]{3,8})$/.exec(value)?.[1];
+  if (hex) {
+    if (hex.length === 3 || hex.length === 4) {
+      const [r, g, b] = [...hex.slice(0, 3)];
+      return `#${r}${r}${g}${g}${b}${b}`;
+    }
+    if (hex.length === 6 || hex.length === 8) return `#${hex.slice(0, 6)}`;
+    return undefined;
+  }
+
+  const rgb = /^rgba?\(([^)]+)\)$/.exec(value)?.[1];
+  if (rgb) {
+    const parts = rgb.split(/[\s,/]+/).filter(Boolean).slice(0, 3);
+    if (parts.length !== 3) return undefined;
+    const bytes = parts.map((p) => {
+      const n = parseFloat(p);
+      if (!Number.isFinite(n)) return NaN;
+      return clampByte(p.endsWith("%") ? (n / 100) * 255 : n);
+    });
+    if (bytes.some(Number.isNaN)) return undefined;
+    return `#${bytes.map((b) => b.toString(16).padStart(2, "0")).join("")}`;
+  }
+
+  return undefined;
+}
+
 // ── JSON-LD helpers (file-private) ────────────────────────────────────────────
 
 type JsonLdResult = {
@@ -281,6 +392,10 @@ export function extractLargeImage(
  * Collect all `<link rel="icon">` / `<link rel="apple-touch-icon">` tags, rank
  * them by declared size (largest wins), and return the best resolved URL.
  * Falls back to the first match when no `sizes` attribute is present.
+ *
+ * SVG icons are ranked above everything: they carry no `sizes` attribute, so
+ * they'd otherwise score 0 and lose to a 16×16 PNG, yet they scale cleanly to
+ * whatever size the placeholder renders them at.
  */
 export function extractBestIcon(
   html: string,
@@ -302,7 +417,13 @@ export function extractBestIcon(
     if (!href) continue;
     const sizesStr = sizesRe.exec(tag)?.[1] ?? "";
     const sm = sizesStr.match(/(\d+)x(\d+)/i);
-    const area = sm ? parseInt(sm[1]) * parseInt(sm[2]) : 0;
+    const isSvg = /\.svg(\?|$)/i.test(href) ||
+      /\btype=["']image\/svg\+xml["']/i.test(tag);
+    const area = isSvg
+      ? Number.MAX_SAFE_INTEGER
+      : sm
+      ? parseInt(sm[1]) * parseInt(sm[2])
+      : 0;
     try {
       candidates.push({ href: new URL(href, baseUrl).toString(), area });
     } catch {
@@ -431,24 +552,46 @@ export function isValidHttpUrl(raw: string): boolean {
   }
 }
 
-export async function fetchRichContent(
+export interface FetchRichContentResult {
+  /** False when the page couldn't be reached at all, as opposed to reached and
+   * found to carry no metadata. Callers that already hold good metadata must
+   * not overwrite it with a failure stub. */
+  ok: boolean;
+  content?: RichContent;
+}
+
+/**
+ * Fetch metadata for `url`, reporting whether the fetch itself succeeded.
+ *
+ * On failure it still yields a minimal stub so a *new* dump has something
+ * displayable, but `ok: false` lets callers with existing metadata keep it.
+ */
+export async function tryFetchRichContent(
   url: string,
-): Promise<RichContent | undefined> {
+): Promise<FetchRichContentResult> {
   try {
     const provider = providers.find((p) => p.matches(url))!;
-    return await provider.fetch(url);
+    return { ok: true, content: await provider.fetch(url) };
   } catch (err) {
     console.error(`[rich-content] Failed to fetch metadata for ${url}:`, err);
-    // Return a minimal stub so the caller always gets something displayable
-    // (e.g. when the site has a bad TLS cert or the fetch times out).
     try {
       return {
+        ok: false,
+        content: {
           type: "generic",
           url,
           siteName: new URL(url).hostname.replace(/^www\./, ""),
+        },
       };
     } catch {
-      return undefined;
+      return { ok: false };
     }
   }
 }
+
+/** Metadata for `url`, or a minimal stub when it can't be fetched. */
+export async function fetchRichContent(
+  url: string,
+): Promise<RichContent | undefined> {
+  return (await tryFetchRichContent(url)).content;
+}

src/App.css

@@ -2534,6 +2534,12 @@ body.has-player .chat-fab {
   margin-top: 0.75rem;
 }
 
+.dump-edit-refresh-error {
+  margin-top: 0.5rem;
+  font-size: 0.85rem;
+  color: var(--color-danger);
+}
+
 .dump-edit-thumbnail-row {
   display: flex;
   align-items: center;
@@ -3009,6 +3015,76 @@ body.has-player .chat-fab {
   line-height: 1;
 }
 
+/* ── Generated thumbnail placeholder ──
+   Stands in for pages that offer no preview image. The site's own color is
+   mixed *into* the theme surface rather than painted raw, so an arbitrary
+   third-party accent can never break contrast against --color-text — in any
+   style, in either color scheme. Themes tune --thumb-tint-strength alone. */
+/* Zero-specificity sizing: the placeholder fills its box by default, but any
+   class it shares with the <img> it replaces (.rich-content-thumbnail's 180px,
+   .rich-content-compact-thumbnail's 36px) still wins, so it lands exactly where
+   the image would have. */
+:where(.thumb-placeholder) {
+  width: 100%;
+  height: 100%;
+}
+
+.thumb-placeholder {
+  min-width: 0;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  overflow: hidden;
+  user-select: none;
+  color: var(--color-text);
+  background:
+    linear-gradient(135deg, rgba(255, 255, 255, 0.12), rgba(0, 0, 0, 0.12)),
+    color-mix(
+      in srgb,
+      var(--thumb-tint, var(--color-accent)) var(--thumb-tint-strength, 34%),
+      var(--color-surface)
+    );
+}
+
+.thumb-placeholder-icon {
+  max-width: 44%;
+  max-height: 44%;
+  object-fit: contain;
+  display: block;
+}
+
+.thumb-placeholder-initials {
+  font-size: 1.25rem;
+  font-weight: 800;
+  line-height: 1;
+  opacity: 0.75;
+  letter-spacing: 0.02em;
+}
+
+/* The initial has no intrinsic size, so scale it per surface. */
+.dump-card-preview .thumb-placeholder-initials,
+.playlist-card-preview .thumb-placeholder-initials {
+  font-size: 1.9rem;
+}
+
+.journal-card-image .thumb-placeholder-initials {
+  font-size: 2.6rem;
+}
+
+.rich-content-thumbnail.thumb-placeholder .thumb-placeholder-initials {
+  font-size: 3rem;
+}
+
+/* `.rich-content-thumbnail` sizes an <img> by width alone and lets the natural
+   aspect supply the height, which a <div> has none of. Stretching to the card's
+   height matches the image; the floor keeps it from collapsing when there's
+   little text, or once the card stacks on narrow screens. */
+.rich-content-thumbnail.thumb-placeholder {
+  height: auto;
+  align-self: stretch;
+  min-height: 110px;
+}
+
 /* Fill the 48×48 preview box and center content for media buttons */
 .dump-card-preview .rich-content-thumbnail-btn {
   width: 100%;

src/components/DumpCard.tsx

@@ -8,6 +8,7 @@ import { useCategories } from "../hooks/useCategories.ts";
 import { isDumpVisited, isRecent, markDumpVisited } from "../utils/visited.ts";
 import FilePreview from "./FilePreview.tsx";
 import RichContentCard from "./RichContentCard.tsx";
+import ThumbnailPlaceholder from "./ThumbnailPlaceholder.tsx";
 import { VoteButton } from "./VoteButton.tsx";
 import { Markdown } from "./Markdown.tsx";
 import { Tooltip } from "./Tooltip.tsx";
@@ -65,7 +66,7 @@ export function DumpCard(
                     : undefined}
                 />
               )
-              : <span className="dump-card-preview-icon">🔗</span>}
+              : <ThumbnailPlaceholder url={dump.url} />}
           </div>
 
           <div className="dump-card-vote" onClick={(e) => e.stopPropagation()}>

src/components/ImagePicker.tsx

@@ -47,6 +47,7 @@ export function ImagePicker({
             alt={alt}
             className="img-picker-img"
             style={{ borderRadius }}
+            referrerPolicy="no-referrer"
           />
         )
         : (

src/components/JournalCard.tsx

@@ -2,7 +2,6 @@ import { useContext } from "react";
 import { Link, useNavigate } from "react-router";
 import { Plural, Trans } from "@lingui/react/macro";
 import type { Dump } from "../model.ts";
-import { API_URL } from "../config/api.ts";
 import { relativeTime } from "../utils/relativeTime.ts";
 import { dumpFileUrl, dumpThumbnailUrl, dumpUrl } from "../utils/urls.ts";
 import { useAuth } from "../hooks/useAuth.ts";
@@ -11,6 +10,7 @@ import { hasQuote, hasThumbnail, type JournalShape } from "../utils/journalLayou
 import { VoteButton } from "./VoteButton.tsx";
 import { Markdown } from "./Markdown.tsx";
 import { Tooltip } from "./Tooltip.tsx";
+import Thumbnail from "./Thumbnail.tsx";
 import { PlayerContext } from "../contexts/PlayerContext.ts";
 
 export type { JournalShape };
@@ -41,31 +41,13 @@ export function JournalCard(
     navigate(dumpUrl(dump));
   }
 
-  const rawThumbnail =
+  const thumbnailUrl =
     dump.kind === "file" && dump.fileMime?.startsWith("image/")
       ? dumpFileUrl(dump, token)
       : dump.thumbnailMime
       ? dumpThumbnailUrl(dump, token)
       : (dump.richContent?.thumbnailUrl ?? null);
 
-  // Route external HTTP thumbnails through the server proxy to avoid
-  // mixed-content blocks when the frontend is served over HTTPS.
-  const thumbnailUrl = (() => {
-    if (!rawThumbnail) return null;
-    try {
-      const u = new URL(rawThumbnail);
-      if (
-        u.protocol === "http:" && u.hostname !== "localhost" &&
-        u.hostname !== "127.0.0.1"
-      ) {
-        return `${API_URL}/api/proxy-image?url=${
-          encodeURIComponent(rawThumbnail)
-        }`;
-      }
-    } catch { /* relative URL */ }
-    return rawThumbnail;
-  })();
-
   // Content mode is independent of grid footprint: a thumbnailed dump reads as
   // an image card, a thumbnail-less dump with a note becomes a pull-quote, and
   // everything else falls back to a typographic text card.
@@ -167,12 +149,13 @@ export function JournalCard(
           : handleNavigate}
       >
         <div className="journal-card-image">
-          <img
+          <Thumbnail
             src={thumbnailUrl ?? undefined}
-            alt=""
-            loading="lazy"
-            onError={(e) => {
-              (e.target as HTMLImageElement).style.visibility = "hidden";
+            placeholder={{
+              url: dump.url,
+              accentColor: dump.richContent?.accentColor,
+              faviconUrl: dump.richContent?.faviconUrl,
+              siteName: dump.richContent?.siteName,
             }}
           />
           {embedUrl && (

src/components/RichContentCard.tsx

@@ -1,21 +1,7 @@
 import { useContext } from "react";
 import type { RichContent } from "../model.ts";
 import { PlayerContext } from "../contexts/PlayerContext.ts";
-import { API_URL } from "../config/api.ts";
-
-/** Route HTTP thumbnail URLs through the server proxy to avoid mixed-content blocks. */
-function proxyIfHttp(url: string): string {
-  try {
-    const u = new URL(url);
-    if (
-      u.protocol === "http:" && u.hostname !== "localhost" &&
-      u.hostname !== "127.0.0.1"
-    ) {
-      return `${API_URL}/api/proxy-image?url=${encodeURIComponent(url)}`;
-    }
-  } catch { /* relative URL — leave as-is */ }
-  return url;
-}
+import Thumbnail from "./Thumbnail.tsx";
 
 interface RichContentCardProps {
   richContent: RichContent;
@@ -31,12 +17,26 @@ export default function RichContentCard(
     RichContentCardProps,
 ) {
   const { play, current, playing } = useContext(PlayerContext);
-  const thumbnailSrc = thumbnailOverrideUrl ??
-    (richContent.thumbnailUrl
-      ? proxyIfHttp(richContent.thumbnailUrl)
-      : undefined);
+  const thumbnailSrc = thumbnailOverrideUrl ?? richContent.thumbnailUrl;
+
+  const placeholder = {
+    url: richContent.url,
+    accentColor: richContent.accentColor,
+    faviconUrl: richContent.faviconUrl,
+    siteName: richContent.siteName,
+  };
 
   if (compact) {
+    const thumbnail = (
+      <Thumbnail
+        src={thumbnailSrc}
+        alt={richContent.title ?? ""}
+        className="rich-content-compact-thumbnail"
+        placeholder={placeholder}
+        placeholderClassName="rich-content-compact-thumbnail"
+      />
+    );
+
     if (richContent.embedUrl) {
       const isActive = current?.kind === "embed" &&
         current.embedUrl === richContent.embedUrl;
@@ -60,18 +60,7 @@ export default function RichContentCard(
           }}
           aria-label={isPlaying ? "Pause" : "Play"}
         >
-          {thumbnailSrc
-            ? (
-              <img
-                src={thumbnailSrc}
-                alt={richContent.title ?? ""}
-                className="rich-content-compact-thumbnail"
-                onError={(e) => {
-                  (e.target as HTMLImageElement).style.display = "none";
-                }}
-              />
-            )
-            : <span className="rich-content-compact-icon">▶</span>}
+          {thumbnail}
           <span className="rich-content-play-overlay">
             {isPlaying ? "⏸" : "▶"}
           </span>
@@ -87,26 +76,24 @@ export default function RichContentCard(
         className="rich-content-compact"
         onClick={(e) => e.stopPropagation()}
       >
-        {thumbnailSrc
-          ? (
-            <img
-              src={thumbnailSrc}
-              alt={richContent.title ?? ""}
-              className="rich-content-compact-thumbnail"
-              onError={(e) => {
-                (e.target as HTMLImageElement).style.display = "none";
-              }}
-            />
-          )
-          : <span className="rich-content-compact-icon">🔗</span>}
+        {thumbnail}
       </a>
     );
   }
 
   const canPlay = !!richContent.embedUrl;
 
-  const thumbnail = thumbnailSrc && (
-    canPlay
+  const thumbnailImg = (
+    <Thumbnail
+      src={thumbnailSrc}
+      alt={richContent.title ?? ""}
+      className="rich-content-thumbnail"
+      placeholder={placeholder}
+      placeholderClassName="rich-content-thumbnail"
+    />
+  );
+
+  const thumbnail = canPlay
     ? (
       <button
         type="button"
@@ -121,28 +108,11 @@ export default function RichContentCard(
           })}
         aria-label="Play"
       >
-          <img
-            src={thumbnailSrc}
-            alt={richContent.title ?? ""}
-            className="rich-content-thumbnail"
-            onError={(e) => {
-              (e.target as HTMLImageElement).style.display = "none";
-            }}
-          />
+        {thumbnailImg}
         <span className="rich-content-play-overlay">▶</span>
       </button>
     )
-      : (
-        <img
-          src={thumbnailSrc}
-          alt={richContent.title ?? ""}
-          className="rich-content-thumbnail"
-          onError={(e) => {
-            (e.target as HTMLImageElement).style.display = "none";
-          }}
-        />
-      )
-  );
+    : thumbnailImg;
 
   return (
     <div className={`rich-content-card rich-content-card--${richContent.type}`}>

src/components/Thumbnail.tsx

@@ -0,0 +1,73 @@
+import { useState } from "react";
+import { canProxyImage, proxyImageUrl } from "../utils/proxyImage.ts";
+import ThumbnailPlaceholder from "./ThumbnailPlaceholder.tsx";
+
+interface ThumbnailProps {
+  /** Raw image URL. Proxying is decided here — don't pre-proxy it. */
+  src?: string;
+  alt?: string;
+  className?: string;
+  loading?: "lazy" | "eager";
+  /** Passed through to the placeholder when there's nothing to show. */
+  placeholder: {
+    url?: string;
+    accentColor?: string;
+    faviconUrl?: string;
+    siteName?: string;
+  };
+  /** Extra class for the placeholder element only. */
+  placeholderClassName?: string;
+}
+
+/**
+ * An external thumbnail that always renders *something*.
+ *
+ * Three attempts, in order:
+ *  1. load it directly with no `Referer` — hotlink protection (Cloudflare's is
+ *     one click) answers a cross-site referrer with 403, and an empty one with
+ *     200;
+ *  2. retry through `/api/proxy-image`, which fetches server-side, for hosts
+ *     that reject an empty referrer too;
+ *  3. fall back to the generated placeholder.
+ *
+ * Before this existed each of these failures ended at `display: none`, leaving
+ * an empty framed box and no signal anywhere that a load had failed.
+ */
+export default function Thumbnail(
+  { src, alt = "", className, loading = "lazy", placeholder, placeholderClassName }:
+    ThumbnailProps,
+) {
+  const [attempt, setAttempt] = useState<"direct" | "proxied" | "failed">(
+    "direct",
+  );
+
+  // A new src is a fresh thing to try — reset during render rather than in an
+  // effect (same shape as Avatar.tsx).
+  const [prevSrc, setPrevSrc] = useState(src);
+  if (prevSrc !== src) {
+    setPrevSrc(src);
+    setAttempt("direct");
+  }
+
+  if (!src || attempt === "failed") {
+    return (
+      <ThumbnailPlaceholder {...placeholder} className={placeholderClassName} />
+    );
+  }
+
+  return (
+    <img
+      src={attempt === "proxied"
+        ? proxyImageUrl(src, { force: true })
+        : proxyImageUrl(src)}
+      alt={alt}
+      className={className}
+      loading={loading}
+      referrerPolicy="no-referrer"
+      onError={() =>
+        setAttempt(
+          attempt === "direct" && canProxyImage(src) ? "proxied" : "failed",
+        )}
+    />
+  );
+}

src/components/ThumbnailPlaceholder.tsx

@@ -0,0 +1,66 @@
+import { useState } from "react";
+import { proxyImageUrl } from "../utils/proxyImage.ts";
+import { initialsFor, tintFor } from "../utils/thumbnailTint.ts";
+
+interface ThumbnailPlaceholderProps {
+  /** The dumped URL — seeds the fallback hue and the initial. */
+  url?: string;
+  /** The target page's declared brand color, if it had one. */
+  accentColor?: string;
+  /** The target page's icon, drawn contained over the tint. */
+  faviconUrl?: string;
+  /** Preferred source for the initial when there's no favicon. */
+  siteName?: string;
+  className?: string;
+}
+
+/**
+ * Stand-in artwork for pages that offer no preview image: the site's own color
+ * washed over the theme surface, with its favicon centered on top — or its
+ * initial when the favicon is missing or fails to load.
+ *
+ * Fills whatever box it's placed in, so the same component serves the 36px
+ * compact thumbnail, the 128×72 feed preview and a 2×2 mosaic tile.
+ */
+export default function ThumbnailPlaceholder(
+  { url, accentColor, faviconUrl, siteName, className }:
+    ThumbnailPlaceholderProps,
+) {
+  const [iconFailed, setIconFailed] = useState(false);
+
+  // A different icon is a fresh thing to try — clear the prior failure during
+  // render rather than in an effect (same shape as Avatar.tsx).
+  const [prevIcon, setPrevIcon] = useState(faviconUrl);
+  if (prevIcon !== faviconUrl) {
+    setPrevIcon(faviconUrl);
+    setIconFailed(false);
+  }
+
+  const style = { "--thumb-tint": tintFor({ accentColor, url }) } as
+    React.CSSProperties;
+
+  return (
+    <div
+      className={`thumb-placeholder${className ? ` ${className}` : ""}`}
+      style={style}
+      aria-hidden="true"
+    >
+      {faviconUrl && !iconFailed
+        ? (
+          <img
+            src={proxyImageUrl(faviconUrl)}
+            alt=""
+            loading="lazy"
+            referrerPolicy="no-referrer"
+            className="thumb-placeholder-icon"
+            onError={() => setIconFailed(true)}
+          />
+        )
+        : (
+          <span className="thumb-placeholder-initials">
+            {initialsFor(siteName, url)}
+          </span>
+        )}
+    </div>
+  );
+}

src/model.ts

@@ -41,7 +41,12 @@ export interface RichContent {
   siteName?: string;
   title?: string;
   description?: string;
+  /** A real preview image — never a favicon. Absent means "no artwork". */
   thumbnailUrl?: string;
+  /** The page's own icon, used as the placeholder's glyph. */
+  faviconUrl?: string;
+  /** The page's declared brand color, normalized to `#rrggbb`. */
+  accentColor?: string;
   videoId?: string;
   embedUrl?: string;
 }

src/pages/DumpEdit.tsx

@@ -53,6 +53,7 @@ export function DumpEdit() {
 
   const [confirmDelete, setConfirmDelete] = useState(false);
   const [refreshing, setRefreshing] = useState(false);
+  const [refreshError, setRefreshError] = useState<string | null>(null);
   const [thumbUploading, setThumbUploading] = useState(false);
 
   useEffect(() => {
@@ -85,15 +86,20 @@ export function DumpEdit() {
     if (state.status !== "loaded" || state.dump.kind !== "url") return;
 
     setRefreshing(true);
+    setRefreshError(null);
     try {
       const res = await authFetch(
         `${API_URL}/api/dumps/${state.dump.id}/refresh-metadata`,
         { method: "POST" },
       );
-      const apiResponse = await res.json();
+      const apiResponse = parseAPIResponse<RawDump>(await res.json());
       if (apiResponse.success) {
         setState({ status: "loaded", dump: deserializeDump(apiResponse.data) });
+      } else {
+        setRefreshError(apiResponse.error.message);
       }
+    } catch (err) {
+      setRefreshError(friendlyFetchError(err));
     } finally {
       setRefreshing(false);
     }
@@ -235,6 +241,9 @@ export function DumpEdit() {
                 : <Trans>Refresh metadata</Trans>}
             </button>
           )}
+          {refreshError && (
+            <p className="dump-edit-refresh-error">{refreshError}</p>
+          )}
         </div>
 
         <DumpEditForm

src/themes/geocities.css

@@ -315,6 +315,20 @@
 [data-style="geocities"] .playlist-card-delete-btn,
 [data-style="geocities"] .emoji-picker-float [frimousse-emoji],
 [data-style="geocities"] .emoji-picker-close-btn,
+/* Turn the tint up and give it hard diagonal bands — a flat wash reads as an
+   unstyled gap in a theme built on saturation. */
+[data-style="geocities"] {
+  --thumb-tint-strength: 55%;
+}
+
+[data-style="geocities"] .thumb-placeholder {
+  background-image: repeating-linear-gradient(
+    135deg,
+    rgba(255, 255, 255, 0.14) 0 8px,
+    rgba(0, 0, 0, 0.14) 8px 16px
+  );
+}
+
 [data-style="geocities"] .btn--ghost,
 [data-style="geocities"] .new-item-toggle,
 [data-style="geocities"] .audio-player-btn,

src/themes/nyt.css

@@ -587,10 +587,17 @@
 [data-style="nyt"] .rich-content-compact-icon,
 [data-style="nyt"] .journal-card-glyph,
 [data-style="nyt"] .fdz__file-icon,
+[data-style="nyt"] .thumb-placeholder-icon,
 [data-style="nyt"] .empty-state {
   filter: grayscale(1);
 }
 
+/* Monochrome by design — a dumped site's brand color doesn't get to tint the
+   page, so the placeholder is the theme's own surface with a gray glyph. */
+[data-style="nyt"] {
+  --thumb-tint-strength: 0%;
+}
+
 /* ── Tighter, continuous ruled feed (no inter-item gap; the hairline
    bottom rules read as one column). Even vertical padding per item. ── */
 [data-style="nyt"] .dump-feed {

src/utils/proxyImage.ts

@@ -0,0 +1,57 @@
+import { API_URL } from "../config/api.ts";
+
+/** Our own API origin — `API_URL` is relative ("") when we're same-origin. */
+function apiOrigin(): string {
+  try {
+    return new URL(API_URL, location.href).origin;
+  } catch {
+    return location.origin;
+  }
+}
+
+/**
+ * Whether `url` points at a third party, i.e. whether proxying it would
+ * actually change anything. Our own files and thumbnails are served with no
+ * `Referer` checks, so retrying them through the proxy is pure waste.
+ */
+export function canProxyImage(url: string): boolean {
+  try {
+    const u = new URL(url, location.href);
+    if (u.protocol !== "http:" && u.protocol !== "https:") return false;
+    return u.origin !== apiOrigin() && u.origin !== location.origin;
+  } catch {
+    return false;
+  }
+}
+
+interface ProxyImageOptions {
+  /**
+   * Proxy even when the URL is already HTTPS. Used as a retry after a direct
+   * load fails — typically hotlink protection rejecting our cross-site
+   * `Referer`, which the server-side fetch doesn't send.
+   */
+  force?: boolean;
+}
+
+/**
+ * Route an external image through `GET /api/proxy-image`.
+ *
+ * By default only HTTP URLs are proxied, so they don't trigger mixed-content
+ * blocks when the frontend is served over HTTPS. `force` opts an HTTPS URL in
+ * as well.
+ */
+export function proxyImageUrl(url: string, opts: ProxyImageOptions = {}): string {
+  let u: URL;
+  try {
+    u = new URL(url);
+  } catch {
+    return url; // relative or same-origin path — nothing to proxy
+  }
+  if (u.protocol !== "http:" && u.protocol !== "https:") return url;
+
+  const isLocal = u.hostname === "localhost" || u.hostname === "127.0.0.1";
+  if (isLocal) return url;
+  if (!opts.force && u.protocol !== "http:") return url;
+
+  return `${API_URL}/api/proxy-image?url=${encodeURIComponent(url)}`;
+}

src/utils/thumbnailTint.ts

@@ -0,0 +1,63 @@
+/**
+ * Color and lettering for generated thumbnail placeholders.
+ *
+ * The tint is never painted on its own — it's mixed into the theme's surface
+ * color by CSS (`--thumb-tint`), so contrast against `--color-text` holds for
+ * any site color, in every style, in both light and dark.
+ */
+
+/**
+ * `accentColor` comes from a dumped page's `theme-color`, so it's
+ * attacker-controlled. Custom properties bypass CSS value parsing and get
+ * substituted verbatim wherever the var is used, so the canonical form is
+ * re-checked here before it ever reaches a style object.
+ */
+export function isSafeHex(value: string | undefined): value is string {
+  return !!value && /^#[0-9a-f]{6}$/.test(value);
+}
+
+/** FNV-1a — small, stable, and well spread across the hue circle. */
+function hashString(seed: string): number {
+  let hash = 0x811c9dc5;
+  for (let i = 0; i < seed.length; i++) {
+    hash ^= seed.charCodeAt(i);
+    hash = Math.imul(hash, 0x01000193);
+  }
+  return hash >>> 0;
+}
+
+/** A stable hue for a string, so the same site always gets the same tint. */
+export function hueFromString(seed: string): string {
+  return `hsl(${hashString(seed) % 360} 55% 55%)`;
+}
+
+function hostnameOf(url: string | undefined): string | undefined {
+  if (!url) return undefined;
+  try {
+    return new URL(url).hostname.replace(/^www\./, "");
+  } catch {
+    return undefined;
+  }
+}
+
+/**
+ * The page's own brand color when it declared a usable one, otherwise a hue
+ * derived from its hostname — so every card gets a tint, including rows saved
+ * before accent extraction existed.
+ */
+export function tintFor(
+  { accentColor, url }: { accentColor?: string; url?: string },
+): string {
+  if (isSafeHex(accentColor)) return accentColor;
+  return hueFromString(hostnameOf(url) ?? url ?? "");
+}
+
+/** The letter drawn when there's no favicon to show. */
+export function initialsFor(
+  siteName: string | undefined,
+  url: string | undefined,
+): string {
+  const source = siteName?.trim() || hostnameOf(url) || url || "";
+  const letter = [...source].find((ch) => /\p{L}|\p{N}/u.test(ch));
+  return (letter ?? "?").toUpperCase();
+}