diff --git a/app/app.py b/app/app.py
index ce6f90e..e2d8467 100644
--- a/app/app.py
+++ b/app/app.py
@@ -692,10 +692,19 @@ def check_resize():
     stem    = re.sub(r"_\d+x\d+$", "", target.stem)
     parent  = target.parent
 
+    all_dims = [(s, s) for s in sizes]
+    for cs in request.form.getlist("custom_sizes"):
+        try:
+            w, h = (int(x.strip()) for x in re.split(r"[x×]", cs.lower()))
+            if w >= 1 and h >= 1:
+                all_dims.append((w, h))
+        except (ValueError, TypeError):
+            pass
+
     conflicts = []
     for fmt in formats:
-        for size in sizes:
-            out_name = f"{stem}_{size}x{size}.{fmt}"
+        for w, h in all_dims:
+            out_name = f"{stem}_{w}x{h}.{fmt}"
             if (parent / out_name).exists():
                 conflicts.append(out_name)
 
@@ -710,11 +719,12 @@ def resize_image():
     if redir:
         return redir
 
-    subpath = request.form.get("path", "").strip()
+    subpath     = request.form.get("path", "").strip()
     raw_sizes   = request.form.getlist("sizes")
     raw_formats = request.form.getlist("formats")
+    raw_customs = request.form.getlist("custom_sizes")
 
-    if not subpath or not raw_sizes or not raw_formats:
+    if not subpath or not raw_formats:
         return jsonify({"error": "Paramètres manquants"}), 400
 
     target = _safe_path(subpath)
@@ -730,13 +740,32 @@ def resize_image():
         abort(403)
 
     try:
-        sizes = sorted({int(s) for s in raw_sizes if int(s) in RESIZE_SIZES})
+        square_dims = [(s, s) for s in sorted({int(s) for s in raw_sizes if int(s) in RESIZE_SIZES})]
     except (ValueError, TypeError):
-        return jsonify({"error": "Tailles invalides"}), 400
+        square_dims = []
 
     formats = [f for f in raw_formats if f in RESIZE_FORMATS]
-    if not sizes or not formats:
-        return jsonify({"error": "Tailles ou formats invalides"}), 400
+
+    # Dimensions libres — validées contre la résolution source
+    src_img   = Image.open(target)
+    max_w, max_h = src_img.width, src_img.height
+    src_img.close()
+
+    custom_dims = []
+    for cs in raw_customs:
+        try:
+            w, h = (int(x.strip()) for x in re.split(r"[x×]", cs.lower()))
+            if w < 1 or h < 1:
+                continue
+            if w > max_w or h > max_h:
+                continue
+            custom_dims.append((w, h))
+        except (ValueError, TypeError):
+            pass
+
+    all_dims = square_dims + custom_dims
+    if not all_dims or not formats:
+        return jsonify({"error": "Aucune dimension ou format valide"}), 400
 
     conflict = request.form.get("conflict", "skip")
     if conflict not in ("backup", "overwrite", "rename", "skip"):
@@ -747,9 +776,20 @@ def resize_image():
     parent = target.parent
     created, errors = [], []
 
+    # Signaler les dimensions hors-bornes
+    for cs in raw_customs:
+        try:
+            w, h = (int(x.strip()) for x in re.split(r"[x×]", cs.lower()))
+            if w > max_w or h > max_h:
+                for f in formats:
+                    errors.append({"name": f"{stem}_{w}x{h}.{f}",
+                                   "reason": f"{w}×{h} dépasse la résolution source ({max_w}×{max_h})"})
+        except (ValueError, TypeError):
+            pass
+
     for fmt in formats:
-        for size in sizes:
-            out_name = f"{stem}_{size}x{size}.{fmt}"
+        for w, h in all_dims:
+            out_name = f"{stem}_{w}x{h}.{fmt}"
             out_path = parent / out_name
             out_rel  = str(out_path.relative_to(ASSETS_ROOT))
 
@@ -768,7 +808,6 @@ def resize_image():
                     out_path = _auto_rename(out_path)
                     out_name = out_path.name
                     out_rel  = str(out_path.relative_to(ASSETS_ROOT))
-                # conflict == "overwrite" : on continue sans rien faire
 
             try:
                 if fmt == "svg" and is_svg:
@@ -785,17 +824,17 @@ def resize_image():
                     if fmt in ("png", "ico"):
                         buf = io.BytesIO()
                         _cairosvg.svg2png(url=str(target), write_to=buf,
-                                          output_width=size, output_height=size)
+                                          output_width=w, output_height=h)
                         buf.seek(0)
                         img = Image.open(buf).convert("RGBA")
                         if fmt == "ico":
-                            img.save(out_path, format="ICO", sizes=[(size, size)])
+                            img.save(out_path, format="ICO", sizes=[(w, h)])
                         else:
                             img.save(out_path, format="PNG")
-                    else:  # jpg
+                    else:
                         buf = io.BytesIO()
                         _cairosvg.svg2png(url=str(target), write_to=buf,
-                                          output_width=size, output_height=size)
+                                          output_width=w, output_height=h)
                         buf.seek(0)
                         img = Image.open(buf).convert("RGB")
                         img.save(out_path, format="JPEG", quality=90)
@@ -803,7 +842,7 @@ def resize_image():
 
                 else:
                     img = Image.open(target)
-                    img = img.resize((size, size), Image.LANCZOS)
+                    img = img.resize((w, h), Image.LANCZOS)
                     if fmt == "png":
                         if img.mode not in ("RGBA", "RGB", "L"):
                             img = img.convert("RGBA")
@@ -813,7 +852,7 @@ def resize_image():
                         img.save(out_path, format="JPEG", quality=90)
                     elif fmt == "ico":
                         img = img.convert("RGBA")
-                        img.save(out_path, format="ICO", sizes=[(size, size)])
+                        img.save(out_path, format="ICO", sizes=[(w, h)])
                     created.append({"name": out_name, "path": out_rel})
 
             except Exception as exc:
diff --git a/app/static/app.css b/app/static/app.css
index fa7f37e..c09e010 100644
--- a/app/static/app.css
+++ b/app/static/app.css
@@ -212,6 +212,16 @@ main { max-width: 1100px; margin: 2rem auto; padding: 0 1.5rem 3rem; display: fl
 .resize-actions { display: flex; align-items: center; gap: 1rem; flex-wrap: wrap; }
 .resize-hint { font-size: .82rem; color: var(--muted); font-style: italic; }
 
+.resize-custom-row { display: flex; align-items: center; gap: .5rem; flex-wrap: wrap; }
+.custom-dim { width: 5.5rem; padding: .35rem .5rem; border: 1.5px solid var(--border); border-radius: 6px;
+              font-size: .9rem; text-align: center; background: var(--surface); color: var(--text); }
+.custom-dim:focus { outline: none; border-color: var(--accent); }
+.custom-dim:invalid { border-color: #ef4444; }
+.custom-dim-sep { font-size: 1rem; color: var(--muted); }
+.custom-dim-unit { font-size: .82rem; color: var(--muted); }
+.custom-square-lock { display: flex; align-items: center; gap: .3rem; font-size: .82rem;
+                      color: var(--muted); cursor: pointer; user-select: none; }
+
 .resize-result { border-top: 1px solid var(--border); padding-top: .9rem; font-size: .88rem; }
 .resize-ok-title  { color: #15803d; font-weight: 600; margin-bottom: .35rem; }
 .resize-err-title { color: #b91c1c; font-weight: 600; margin-bottom: .35rem; }
diff --git a/app/templates/preview_image.html b/app/templates/preview_image.html
index fb76e26..919ba87 100644
--- a/app/templates/preview_image.html
+++ b/app/templates/preview_image.html
@@ -122,6 +122,26 @@
       </div>
     </div>
 
+    {% if meta and meta.width and meta.height %}
+    <div class="resize-group">
+      <div class="resize-group-label">Dimension libre
+        <span class="resize-hint">(max {{ meta.width }} × {{ meta.height }} px)</span>
+      </div>
+      <div class="resize-custom-row">
+        <input type="number" id="custom-w" class="custom-dim" min="1" max="{{ meta.width }}"
+               placeholder="largeur" step="1">
+        <span class="custom-dim-sep">×</span>
+        <input type="number" id="custom-h" class="custom-dim" min="1" max="{{ meta.height }}"
+               placeholder="hauteur" step="1">
+        <span class="custom-dim-unit">px</span>
+        <label class="custom-square-lock">
+          <input type="checkbox" id="custom-square"> carré
+        </label>
+      </div>
+      <span id="custom-error" class="rename-error"></span>
+    </div>
+    {% endif %}
+
     <div class="resize-actions">
       <button id="resize-btn" class="btn btn-primary" disabled>Générer les copies</button>
       <span class="resize-hint">Les fichiers sont créés dans le même dossier</span>
@@ -207,24 +227,66 @@
   const cancelConflict= document.getElementById('resize-cancel-conflict');
   const RESIZE_URL      = {{ url_for('resize_image')  | tojson }};
   const CHECK_RESIZE_URL= {{ url_for('check_resize')  | tojson }};
+  const customW    = document.getElementById('custom-w');
+  const customH    = document.getElementById('custom-h');
+  const customSq   = document.getElementById('custom-square');
+  const customErr  = document.getElementById('custom-error');
   let resizeResolved = false;
 
-  function canSubmit() {
-    return Array.from(szCbs).some(c => c.checked)
-        && Array.from(fmtCbs).some(c => c.checked);
+  /* Sync W↔H when "carré" is checked */
+  if (customW && customH && customSq) {
+    customW.addEventListener('input', () => {
+      if (customSq.checked) customH.value = customW.value;
+      updateBtn(); customErr.textContent = '';
+    });
+    customH.addEventListener('input', () => {
+      if (customSq.checked) customW.value = customH.value;
+      updateBtn(); customErr.textContent = '';
+    });
+    customSq.addEventListener('change', () => {
+      if (customSq.checked && customW.value) customH.value = customW.value;
+      updateBtn();
+    });
   }
-  [...szCbs, ...fmtCbs].forEach(c => c.addEventListener('change', () => {
+
+  function getCustomDim() {
+    if (!customW || !customH) return null;
+    const w = parseInt(customW.value, 10);
+    const h = parseInt(customH.value, 10);
+    if (!w || !h || w < 1 || h < 1) return null;
+    const maxW = parseInt(customW.max, 10);
+    const maxH = parseInt(customH.max, 10);
+    if (maxW && w > maxW) return null;
+    if (maxH && h > maxH) return null;
+    return `${w}x${h}`;
+  }
+
+  function canSubmit() {
+    const hasSizes = Array.from(szCbs).some(c => c.checked) || getCustomDim() !== null;
+    const hasFmts  = Array.from(fmtCbs).some(c => c.checked);
+    return hasSizes && hasFmts;
+  }
+
+  function updateBtn() {
     btn.disabled = !canSubmit();
     conflictPanel.style.display = 'none';
     resizeResolved = false;
-  }));
+  }
+
+  [...szCbs, ...fmtCbs].forEach(c => c.addEventListener('change', updateBtn));
+
+  function appendDims(fd) {
+    szCbs.forEach(c  => { if (c.checked) fd.append('sizes',   c.value); });
+    fmtCbs.forEach(c => { if (c.checked) fd.append('formats', c.value); });
+    const cd = getCustomDim();
+    if (cd) fd.append('custom_sizes', cd);
+  }
 
   async function doResize(conflict) {
     const fd = new FormData();
     fd.append('path',     FILE_PATH);
     fd.append('conflict', conflict);
-    szCbs.forEach(c  => { if (c.checked) fd.append('sizes',   c.value); });
-    fmtCbs.forEach(c => { if (c.checked) fd.append('formats', c.value); });
+    appendDims(fd);
 
     btn.disabled = true;
     btn.textContent = 'Génération en cours…';
@@ -262,10 +324,10 @@
   }
 
   btn.addEventListener('click', async () => {
+    if (customErr) customErr.textContent = '';
     const fd = new FormData();
     fd.append('path', FILE_PATH);
-    szCbs.forEach(c  => { if (c.checked) fd.append('sizes',   c.value); });
-    fmtCbs.forEach(c => { if (c.checked) fd.append('formats', c.value); });
+    appendDims(fd);
 
     let conflicts = [];
     try {