diff --git a/src/components/image-converter.tsx b/src/components/image-converter.tsx
index acff4a8..97d7d0d 100644
--- a/src/components/image-converter.tsx
+++ b/src/components/image-converter.tsx
@@ -344,6 +344,20 @@ export function ImageConverter() {
 
   const hasImages = images.length > 0;
 
+  const handleApplyDefaultBaseNameToAll = () => {
+    if (!defaultBaseName) {
+      toast.error("Please enter a default base name to apply.");
+      return;
+    }
+    if (!hasImages) {
+      toast.info("Upload some images first.");
+      return;
+    }
+    const newFilenames = filenames.map(() => defaultBaseName);
+    setFilenames(newFilenames);
+    toast.success(`Set base name to "${defaultBaseName}" for all ${images.length} images.`);
+  };
+
   return (
     <div className="grid grid-cols-1 lg:grid-cols-3 gap-4 w-full">
       <div className="lg:col-span-1 flex flex-col gap-4 lg:sticky lg:top-8 self-start">
@@ -428,12 +442,17 @@ export function ImageConverter() {
                 {useDefaultBaseName && (
                   <div className="space-y-2">
                     <Label htmlFor="default-base-name">Default base name</Label>
-                    <Input
-                      id="default-base-name"
-                      placeholder="e.g., new-york-trip"
-                      value={defaultBaseName}
-                      onChange={(e) => setDefaultBaseName(e.target.value)}
-                    />
+                    <div className="flex items-center gap-2">
+                      <Input
+                        id="default-base-name"
+                        placeholder="e.g., new-york-trip"
+                        value={defaultBaseName}
+                        onChange={(e) => setDefaultBaseName(e.target.value)}
+                      />
+                      <Button variant="outline" size="sm" onClick={handleApplyDefaultBaseNameToAll} disabled={!defaultBaseName || !hasImages}>
+                        Apply to all
+                      </Button>
+                    </div>
                   </div>
                 )}
                 <div className="space-y-2">