AI Thumbnail Lab — Generate and Test Thumbnails With AI

AI Thumbnail Lab lets you generate a new thumbnail directly from frames of your video or uploaded images, then apply it instantly or run a split test against your current thumbnail to see which one performs better.

Where to Find It

AI Thumbnail Lab is in Vid Settings → Marketing tab → Thumbnails. The Generate With AI button appears under the main thumbnail, the mobile thumbnail, and each exit thumbnail.

How to Generate a Thumbnail 

Add your references — up to three reference images can be used. If the video already has a thumbnail, it is added automatically as the first reference. You can add more by picking frames directly from your video or uploading your own images.

Choose a style — select from ready-made style presets such as Cinematic, Authority, or Vlog. Choose My Prompt if you want to describe the look yourself.

Add optional details:

• Text on Thumbnail — a short headline, up to 6 words or 40 characters
• Prompt — describe the scene, mood, or specific details, up to 500 characters. Required if using My Prompt

Apply best practices — this is on by default and steers the result toward proven thumbnail rules: one focal point, high contrast, real faces and products kept intact, and a clear center for the play button. Leave it on unless you have a specific reason to turn it off.

Click Generate Thumbnail — results typically take under a minute.

What You Can Do With the Result

Apply — replaces the thumbnail it was generated for (main, mobile, or a specific exit thumbnail) immediately. Other thumbnails are not affected.

Run Experiment — opens a new experiment draft with your current thumbnail as the Control and a copy of the video with the generated thumbnail as the Variant. Traffic is split 50/50. Pick a success metric and click Save & Review — from there it works like any other Vidalytics experiment.

Adjust Result — describe what you want to change (e.g. “brighter background” or “tighter crop”) and the AI edits the existing image rather than starting over. Counts as one generation.

Generate Another — returns to the form to start fresh.

Generation History

All generated thumbnails for a video — main, mobile, and exit — are saved in Generation History. Each image shows where it is currently applied (e.g. “Applied · Exit 0:45–1:30”). Any image from History can be applied at any time.

Replacing a Thumbnail

To replace an existing thumbnail, generate a new one and click Apply. This overwrites the current thumbnail for that slot (main, mobile, or a specific exit thumbnail) immediately.

You can also apply any previously generated thumbnail from Generation History — select the image and choose the target slot to apply it to.

Deleting a Thumbnail

To remove a thumbnail entirely, go to Vid Settings → Marketing tab → Thumbnails, hover over the thumbnail you want to remove, and click the delete option. This clears the slot and reverts it to the default video frame.

For additional questions, feedback or assistance please feel free to reach out directly to our Customer Happiness Team at hi@vidalytics.com.