diff --git a/studio/frontend/src/features/studio/sections/params-section.tsx b/studio/frontend/src/features/studio/sections/params-section.tsx
index 56eedfa651..d6489d677c 100644
--- a/studio/frontend/src/features/studio/sections/params-section.tsx
+++ b/studio/frontend/src/features/studio/sections/params-section.tsx
@@ -139,7 +139,8 @@ export function ParamsSection(): ReactElement {
   const [ctxInput, setCtxInput] = useState(String(store.contextLength));
   const ctxAnchorRef = useRef<HTMLDivElement>(null);
   const ctxItems = CONTEXT_LENGTHS.map(String);
-  const visionImageSizePresets = [384, 512, 768, 1024, 1536, 2048];
+  // Backend validator allows [256, 2048]; offer the full span.
+  const visionImageSizePresets = [256, 384, 512, 768, 1024, 1536, 2048];
 
   // Keep input in sync when the store value changes externally
   // (e.g. model defaults being applied after model selection).
@@ -953,6 +954,16 @@ export function ParamsSection(): ReactElement {
                         </SelectTrigger>
                         <SelectContent>
                           <SelectItem value="default">Default</SelectItem>
+                          {store.visionImageSize != null &&
+                            !visionImageSizePresets.includes(
+                              store.visionImageSize,
+                            ) && (
+                              <SelectItem
+                                value={String(store.visionImageSize)}
+                              >
+                                {store.visionImageSize}
+                              </SelectItem>
+                            )}
                           {visionImageSizePresets.map((size) => (
                             <SelectItem key={size} value={String(size)}>
                               {size}
diff --git a/studio/frontend/src/features/studio/sections/training-section.tsx b/studio/frontend/src/features/studio/sections/training-section.tsx
index 46f97c358f..56c0cc22ef 100644
--- a/studio/frontend/src/features/studio/sections/training-section.tsx
+++ b/studio/frontend/src/features/studio/sections/training-section.tsx
@@ -80,7 +80,11 @@ export function TrainingSection() {
   };
 
   const handleSaveConfig = () => {
-    const yamlStr = serializeConfigToYaml(store, store.isVisionModel);
+    // Match the API mapper gate so exported YAML never carries
+    // vision_image_size for non-image datasets.
+    const includeVisionFields =
+      store.isVisionModel && store.isDatasetImage === true;
+    const yamlStr = serializeConfigToYaml(store, includeVisionFields);
     const blob = new Blob([yamlStr], { type: "text/yaml" });
     const url = URL.createObjectURL(blob);
     const a = document.createElement("a");