diff --git a/package.json b/package.json
index e1156c2..058f90a 100644
--- a/package.json
+++ b/package.json
@@ -23,6 +23,7 @@
     "test:suggest": "node --loader ts-node/esm --experimental-specifier-resolution=node src/app/search/suggest.spec.ts && node ./server/tests/suggest.test.mjs",
     "test:transcript": "node --test server/tests/transcript.test.mjs",
     "test:history": "node server/tests/history_filters.test.mjs",
+    "test:highlight": "node --loader ts-node/esm --experimental-specifier-resolution=node src/components/account/history/highlight.util.spec.ts",
     "test:ytscrape": "node server/tests/youtube-scrape.test.mjs",
     "test:ytinnertube": "node server/tests/youtube-innertube.test.mjs",
     "ytdlp:update": "yt-dlp -U || python3 -m yt_dlp -U || echo \"yt-dlp update: installez yt-dlp puis relancez\""
diff --git a/src/components/account/history/highlight.pipe.ts b/src/components/account/history/highlight.pipe.ts
new file mode 100644
index 0000000..0f966ff
--- /dev/null
+++ b/src/components/account/history/highlight.pipe.ts
@@ -0,0 +1,18 @@
+import { Pipe, PipeTransform, inject } from '@angular/core';
+import { DomSanitizer, SafeHtml } from '@angular/platform-browser';
+import { buildHighlightedHtml } from './highlight.util';
+
+/**
+ * Surligne les mots-clés d'une requête dans un texte d'historique.
+ * Usage : `[innerHTML]="item.title | histHighlight: query()"`.
+ * Le HTML est construit par `buildHighlightedHtml` (texte source échappé),
+ * sanitisé ici pour Angular. Pipe pur : recalculé quand texte/requête changent.
+ */
+@Pipe({ name: 'histHighlight', standalone: true })
+export class HistHighlightPipe implements PipeTransform {
+  private sanitizer = inject(DomSanitizer);
+
+  transform(value: string | null | undefined, query: string | null | undefined): SafeHtml {
+    return this.sanitizer.bypassSecurityTrustHtml(buildHighlightedHtml(value, query));
+  }
+}
diff --git a/src/components/account/history/highlight.util.spec.ts b/src/components/account/history/highlight.util.spec.ts
new file mode 100644
index 0000000..2c15fd0
--- /dev/null
+++ b/src/components/account/history/highlight.util.spec.ts
@@ -0,0 +1,77 @@
+import { buildHighlightedHtml, countOccurrences, escapeHtml, highlightTerms } from './highlight.util';
+
+/**
+ * Surlignage des mots-clés de l'Historique.
+ * Run with: npm run test:highlight
+ */
+
+function assertEqual(actual: unknown, expected: unknown, message: string): void {
+  const a = JSON.stringify(actual);
+  const b = JSON.stringify(expected);
+  if (a !== b) {
+    console.error(`FAIL: ${message}\n  actual:   ${a}\n  expected: ${b}`);
+    process.exitCode = 1;
+  } else {
+    console.log(`ok: ${message}`);
+  }
+}
+
+// Termes : uniques, minuscules, plus longs d'abord
+assertEqual(highlightTerms('lofi  LOFI mix'), ['lofi', 'mix'], 'termes dédupliqués + minuscules');
+assertEqual(highlightTerms('  '), [], 'requête vide -> aucun terme');
+assertEqual(highlightTerms('a bb ccc'), ['ccc', 'bb', 'a'], 'tri par longueur décroissante');
+
+// HTML de base
+assertEqual(
+  buildHighlightedHtml('Documentaire Océans', 'océans'),
+  'Documentaire <mark class="hist-mark">Océans</mark>',
+  'match insensible à la casse, casse d origine préservée',
+);
+assertEqual(
+  buildHighlightedHtml('lofi hip hop mix', 'lofi mix'),
+  '<mark class="hist-mark">lofi</mark> hip hop <mark class="hist-mark">mix</mark>',
+  'multi-mots surlignés séparément',
+);
+assertEqual(
+  buildHighlightedHtml('Bonjour', ''),
+  'Bonjour',
+  'sans requête : texte intact, sans mark',
+);
+assertEqual(
+  buildHighlightedHtml('Bonjour', 'xyz'),
+  'Bonjour',
+  'sans match : texte intact, sans mark',
+);
+
+// Sécurité : le texte source est échappé, la requête aussi
+assertEqual(
+  buildHighlightedHtml('<script>alert(1)</script> test', 'test'),
+  '&lt;script&gt;alert(1)&lt;/script&gt; <mark class="hist-mark">test</mark>',
+  'HTML source échappé, pas d injection',
+);
+assertEqual(
+  buildHighlightedHtml('100% bio_pur', '100%'),
+  '<mark class="hist-mark">100%</mark> bio_pur',
+  'caractères spéciaux requête traités littéralement',
+);
+
+// Chevauchements fusionnés en un seul mark
+assertEqual(
+  buildHighlightedHtml('intelligence artificielle', 'intelligence artificielle intel'),
+  '<mark class="hist-mark">intelligence</mark> <mark class="hist-mark">artificielle</mark>',
+  'terme inclus (intel) fusionné, mots adjacents = 2 marks',
+);
+assertEqual(
+  buildHighlightedHtml('abcd', 'abcd abc'),
+  '<mark class="hist-mark">abcd</mark>',
+  'termes strictement imbriqués fusionnés en 1 mark',
+);
+
+// Compteur d'occurrences
+assertEqual(countOccurrences('Lofi lofi LOFI mix', 'lofi'), 3, 'compte insensible à la casse');
+assertEqual(countOccurrences('rien ici', 'xyz'), 0, 'zéro occurrence');
+assertEqual(countOccurrences('abc', ''), 0, 'requête vide -> 0');
+assertEqual(escapeHtml('a&b<"c">'), 'a&amp;b&lt;&quot;c&quot;&gt;', 'escapeHtml complet');
+
+if (process.exitCode) console.error('highlight.util: FAILURES');
+else console.log('highlight.util: ALL OK');
diff --git a/src/components/account/history/highlight.util.ts b/src/components/account/history/highlight.util.ts
new file mode 100644
index 0000000..fd11f9b
--- /dev/null
+++ b/src/components/account/history/highlight.util.ts
@@ -0,0 +1,77 @@
+// Surlignage des mots-clés recherchés dans l'Historique (pur, sans Angular).
+// Le HTML source est TOUJOURS échappé avant insertion des <mark> : aucune
+// injection possible via titres/textes conservés.
+
+/** Échappe le HTML d'un texte brut. */
+export function escapeHtml(s: string): string {
+  return String(s ?? '')
+    .replace(/&/g, '&amp;')
+    .replace(/</g, '&lt;')
+    .replace(/>/g, '&gt;')
+    .replace(/"/g, '&quot;');
+}
+
+/** Découpe la requête en termes uniques, plus longs d'abord (mots entiers ou fragments). */
+export function highlightTerms(query: string | null | undefined): string[] {
+  const words = String(query ?? '').trim().toLowerCase().split(/\s+/).filter(Boolean);
+  return [...new Set(words)].sort((a, b) => b.length - a.length);
+}
+
+/**
+ * Construit le HTML surligné : segments échappés + `<mark class="hist-mark">`
+ * autour de chaque occurrence (insensible à la casse, chevauchements fusionnés).
+ * Sans requête ou sans match : texte échappé, aucun <mark>.
+ */
+export function buildHighlightedHtml(text: string | null | undefined, query: string | null | undefined): string {
+  const raw = String(text ?? '');
+  const terms = highlightTerms(query);
+  if (!raw || !terms.length) return escapeHtml(raw);
+  const lower = raw.toLowerCase();
+  const ranges: Array<[number, number]> = [];
+  for (const term of terms) {
+    let from = 0;
+    for (;;) {
+      const i = lower.indexOf(term, from);
+      if (i === -1) break;
+      ranges.push([i, i + term.length]);
+      from = i + term.length;
+      if (from >= lower.length) break;
+    }
+  }
+  if (!ranges.length) return escapeHtml(raw);
+  ranges.sort((a, b) => a[0] - b[0] || b[1] - a[1]);
+  const merged: Array<[number, number]> = [];
+  for (const r of ranges) {
+    const last = merged[merged.length - 1];
+    if (last && r[0] <= last[1]) last[1] = Math.max(last[1], r[1]);
+    else merged.push([r[0], r[1]]);
+  }
+  let out = '';
+  let pos = 0;
+  for (const [s, e] of merged) {
+    out += escapeHtml(raw.slice(pos, s));
+    out += `<mark class="hist-mark">${escapeHtml(raw.slice(s, e))}</mark>`;
+    pos = e;
+  }
+  return out + escapeHtml(raw.slice(pos));
+}
+
+/** Nombre d'occurrences (insensible à la casse, sans chevauchement) dans un texte. */
+export function countOccurrences(text: string | null | undefined, query: string | null | undefined): number {
+  const raw = String(text ?? '');
+  const terms = highlightTerms(query);
+  if (!raw || !terms.length) return 0;
+  const lower = raw.toLowerCase();
+  let n = 0;
+  for (const term of terms) {
+    let from = 0;
+    for (;;) {
+      const i = lower.indexOf(term, from);
+      if (i === -1) break;
+      n++;
+      from = i + term.length;
+      if (from >= lower.length) break;
+    }
+  }
+  return n;
+}
diff --git a/src/components/account/history/history.component.html b/src/components/account/history/history.component.html
index 2d62d75..25eb717 100644
--- a/src/components/account/history/history.component.html
+++ b/src/components/account/history/history.component.html
@@ -156,12 +156,13 @@
       <li *ngFor="let s of filteredSearch()"
           class="group relative bg-slate-700/50 hover:bg-slate-700/80 rounded-lg overflow-hidden transition-all duration-200">
         <a [routerLink]="['/search']" [queryParams]="getSearchQueryParams(s)" class="block p-4 pr-24 hover:no-underline">
-          <div class="text-slate-100 font-medium group-hover:text-blue-400 transition-colors">{{ s.query }}</div>
+          <div class="text-slate-100 font-medium group-hover:text-blue-400 transition-colors" [innerHTML]="s.query | histHighlight: searchQuery()"></div>
           <div class="flex items-center mt-1 text-xs text-slate-400 gap-2">
             <span class="inline-flex items-center px-2 py-0.5 rounded border" [ngStyle]="getProviderColors(getSearchProvider(s).id)">
               {{ getSearchProvider(s).name }}
             </span>
             <span>{{ formatDate(s.created_at) }}</span>
+            <span *ngIf="searchQuery().trim() && searchMatchCount(s) > 0" class="hist-count">{{ searchMatchCount(s) }} occurrence{{ searchMatchCount(s) > 1 ? 's' : '' }}</span>
           </div>
         </a>
         <button (click)="onDeleteSearch(s)" [disabled]="deletingSearchId() === s.id"
@@ -199,12 +200,13 @@
               </div>
             </div>
             <div class="ml-4 flex-1 min-w-0">
-              <h4 class="text-sm font-medium text-slate-100 group-hover:text-blue-400 truncate">{{ w.title || 'Sans titre' }}</h4>
+              <h4 class="text-sm font-medium text-slate-100 group-hover:text-blue-400 truncate" [innerHTML]="(w.title || 'Sans titre') | histHighlight: watchQuery()"></h4>
               <div class="mt-1 text-xs text-slate-400">
                 <span class="inline-flex items-center px-2 py-0.5 rounded mr-2 border" [ngStyle]="getProviderColors(w.provider)">
                   {{ getProviderDisplayName(w.provider) }}
                 </span>
                 <span>Visionné le {{ formatDate(w.watched_at) }}</span>
+                <span *ngIf="watchQuery().trim() && watchMatchCount(w) > 0" class="hist-count ml-2">{{ watchMatchCount(w) }} occurrence{{ watchMatchCount(w) > 1 ? 's' : '' }}</span>
               </div>
               <div class="mt-1 text-xs text-slate-500">
                 Progression : {{ formatDuration(w.progress_seconds || 0) }} / {{ formatDuration(w.duration_seconds || 0) }}
@@ -245,7 +247,7 @@
               @else { <span class="text-slate-500 text-xs">TXT</span> }
             </div>
             <div class="flex-1 min-w-0">
-              <div class="text-slate-100 font-medium truncate">{{ t.title || t.video_id }}</div>
+              <div class="text-slate-100 font-medium truncate" [innerHTML]="(t.title || t.video_id) | histHighlight: transcriptQuery()"></div>
               <div class="flex flex-wrap items-center gap-2 mt-1 text-xs text-slate-400">
                 <span class="inline-flex items-center px-2 py-0.5 rounded border" [ngStyle]="getProviderColors(t.provider)">
                   {{ getProviderDisplayName(t.provider) }}
@@ -253,8 +255,9 @@
                 <span class="px-2 py-0.5 rounded bg-emerald-600/20 text-emerald-300 border border-emerald-500/30">{{ t.lang }}</span>
                 <span>{{ t.line_count }} passages</span>
                 <span>{{ formatDate(t.updated_at) }}</span>
+                <span *ngIf="transcriptLineQuery().trim() && transcriptMatchCount(t) > 0" class="hist-count">{{ transcriptMatchCount(t) }} occurrence{{ transcriptMatchCount(t) > 1 ? 's' : '' }}</span>
               </div>
-              <p class="mt-1 text-xs text-slate-400 line-clamp-2">{{ t.preview || '—' }}</p>
+              <p class="mt-1 text-xs text-slate-400 line-clamp-2" [innerHTML]="(t.preview || '—') | histHighlight: transcriptQuery()"></p>
             </div>
           </div>
           <div class="mt-3 flex flex-wrap gap-2">
@@ -272,7 +275,7 @@
           <div *ngIf="expandedTranscriptId() === t.id" class="mt-3 max-h-64 overflow-y-auto rounded bg-slate-900/60 p-3 space-y-1">
             <div *ngFor="let l of expandedTranscriptLines()" class="text-xs text-slate-300 flex gap-2">
               <span class="text-slate-500 font-mono shrink-0">[{{ formatDuration(l.t) }}]</span>
-              <span>{{ l.text }}</span>
+              <span [innerHTML]="l.text | histHighlight: transcriptLineQuery()"></span>
             </div>
           </div>
         </div>
diff --git a/src/components/account/history/history.component.ts b/src/components/account/history/history.component.ts
index a01ab80..df9d050 100644
--- a/src/components/account/history/history.component.ts
+++ b/src/components/account/history/history.component.ts
@@ -7,6 +7,8 @@ import { Subject } from 'rxjs';
 import {
   HistoryService, SearchHistoryItem, WatchHistoryItem, TranscriptHistoryItem,
 } from '../../../services/history.service';
+import { HistHighlightPipe } from './highlight.pipe';
+import { countOccurrences } from './highlight.util';
 
 export type HistoryTab = 'search' | 'watch' | 'transcripts';
 export type DateFilter = 'all' | 'today' | 'week' | 'month';
@@ -27,7 +29,25 @@ const PROVIDER_OPTIONS = [
   standalone: true,
   templateUrl: './history.component.html',
   changeDetection: ChangeDetectionStrategy.OnPush,
-  imports: [CommonModule, RouterModule, FormsModule]
+  imports: [CommonModule, RouterModule, FormsModule, HistHighlightPipe],
+  styles: [`
+    .hist-mark {
+      background: rgba(250, 204, 21, 0.75);
+      color: #0f172a;
+      border-radius: 0.25rem;
+      padding: 0 0.15rem;
+    }
+    .hist-count {
+      font-size: 0.7rem;
+      line-height: 1;
+      padding: 0.2rem 0.45rem;
+      border-radius: 9999px;
+      background: rgba(250, 204, 21, 0.15);
+      color: rgb(253, 224, 71);
+      border: 1px solid rgba(250, 204, 21, 0.35);
+      white-space: nowrap;
+    }
+  `]
 })
 export class HistoryComponent {
   private history = inject(HistoryService);
@@ -313,6 +333,31 @@ export class HistoryComponent {
     return !!(this.transcriptQuery() || this.transcriptProvider() || this.transcriptLang() || this.transcriptDate() !== 'all' || this.transcriptSort() !== 'recent' || this.transcriptInnerSearch());
   });
 
+  // ============ Surlignage des mots-clés (mode highlight) ============
+  /** Occurrences de la requête dans le libellé d'une recherche. */
+  searchMatchCount(s: SearchHistoryItem): number {
+    return countOccurrences(s?.query, this.searchQuery());
+  }
+
+  /** Occurrences de la requête dans le titre d'une vidéo visionnée. */
+  watchMatchCount(w: WatchHistoryItem): number {
+    return countOccurrences(w?.title || '', this.watchQuery());
+  }
+
+  /** Requête effective pour le texte d'un transcript : filtre interne d'abord. */
+  transcriptLineQuery(): string {
+    const inner = this.transcriptInnerSearch().trim();
+    return inner || this.transcriptQuery();
+  }
+
+  /** Occurrences dans titre + aperçu + lignes conservées d'un transcript. */
+  transcriptMatchCount(t: TranscriptHistoryItem): number {
+    const q = this.transcriptLineQuery();
+    if (!q.trim()) return 0;
+    const haystack = `${t?.title || ''}\n${t?.preview || ''}\n${(t?.lines || []).map((l) => l?.text || '').join('\n')}`;
+    return countOccurrences(haystack, q);
+  }
+
   // ============ Helpers affichage (conservés) ============
   /** Miniature : stockée, sinon déterministe YouTube (imports Takeout sans vignette). */
   thumbOf(w: WatchHistoryItem): string {