Thumbnail Test and Compare

0:00 To A/B test thumbnails on YouTube, open the video in YouTube Studio on a computer, click A/B Testing under the thumbnail or in the title box, choose Thumbnail only, Title only or Title and thumbnail, and add up to three versions (YouTube Help). YouTube shows the versions to different viewers and, after a few days to two weeks, declares the one with the highest watch time share the winner, not the one with the most clicks. The thumbnail test reached all creators with advanced features in June 2024 (TechCrunch), and title testing was added on Sep 16, 2025 (Search Engine Journal).

Quick facts

Source: Test & compare thumbnails and titles, YouTube Help.

How do I A/B test a thumbnail on YouTube?

1. In YouTube Studio on a computer, open the video: Create > Upload videos for a new one, or Content and the video for an existing one.
2. Click A/B Testing, under Thumbnail or in the Title box.
3. Choose Title only, Thumbnail only or Title and thumbnail.
4. Add up to three versions, then click Done and save.
5. Follow it in the video's Analytics > Reach tab, under "How your A/B test is going", where Manage test also stops it. Results show on the video's Details page too.

Source: YouTube Help. Changing the title or thumbnail by hand during a test ends it.

Why watch time share, not click-through rate?

2:10 YouTube picks the version that earns the largest share of the video's watch time, because a thumbnail that draws clicks from viewers who leave at once does not help the video. A small control group sees only the default version and is left out of the calculation (YouTube Help). Click-through rate is still shown in the YouTube Studio Analytics reach report, but it does not decide the test.

Reading the result

• Winner: one version clearly did better and YouTube applies it.
• Performed same: no meaningful difference; the creator picks the one they prefer.
• Inconclusive: not enough data; the first title or thumbnail uploaded stays as the default.

1:26 A test runs from a few days to two weeks, depending on how many impressions the video gets and how different the versions are (YouTube Help); YouTube's own explainer video allows as little as a few hours for a busy video with very different versions. A video with few views may never reach a winner.

Which videos can be tested?

Long-form videos, live stream archives and Premieres after they have aired. Shorts, scheduled live streams and Premieres before they air cannot be tested, nor can videos made for kids, set to mature audiences or private, and a test on an age-restricted video does not run. A video that later becomes a Short (three minutes or less, square or vertical) loses its tests (YouTube Help). Upload every thumbnail at 1280 x 720 or larger: if one is smaller, all of them are shown at 854 x 480. Sizes and formats are on Custom Thumbnails.

YouTube's own advice

3:01 YouTube's explainer suggests testing titles and thumbnails together, starting with a few older videos and then recent ones, and trying real differences in layout, background, text and where objects sit. For the images themselves it advises a clear focal point, high contrast that stands out in both light and dark mode, and few words, since a lot of text is hard to read while scrolling.

What creators say

0:58 In a Jun 20, 2024 video, when the tool was reaching creators, George Vanous, who runs the Freedom! network, showed where it lives: YouTube Studio, Content, any video, then Test & compare in the thumbnail's menu, where two more thumbnails can be added. If that choice is missing, the channel does not have the feature yet.

3:22 A test runs for up to 14 days, but in George's experience results start to show after 36 to 48 hours. He urged running tests on every video that gets views, because they give "actionable data" for a channel's own audience instead of copying popular channels' thumbnails. Elsewhere in his tips he advises showing the host's face rather than an object or a price, since viewers subscribe to the person they like, and making thumbnails from a template so each takes under a minute; a test is the way to check that advice on a given audience.

5:46 George also stopped one test early when he thought he saw a clear winner, and YouTube recorded it as completed without one: the gap was not statistically significant. Even so, on his video the shorter thumbnail text "YouTube Playables" did better than "New YouTube Playables" and "Play games on YouTube", which he took as a sign that shorter text worked for his channel, not for every channel.

2:48 In a Feb 16, 2024 video, Nick Nimmin found that a purely graphic thumbnail without his face was doing better than the versions with him in it, "a hard pill to swallow", while in a finished test a version with him won; he advised not getting emotionally attached to the outcome. His other advice: test wildly different thumbnails when a video is first published, and keep small changes such as a text color for later, once YouTube knows which viewers to show the video to.

Frequently asked questions

How do I A/B test thumbnails on YouTube? In YouTube Studio on a computer, open the video, click A/B Testing under the thumbnail, choose Thumbnail only and upload up to three thumbnails. YouTube picks the winner by watch time share.

Can I A/B test YouTube titles? Yes. Since Sep 16, 2025, YouTube's Test and compare can test up to three titles, or titles paired with thumbnails, in YouTube Studio.

How long does a YouTube thumbnail test take? A YouTube thumbnail test runs from a few days to two weeks, depending on the video's impressions and how different the versions are.

Why can't I see A/B Testing in YouTube Studio? YouTube's Test and compare needs advanced features and YouTube Studio on a computer, and does not work on Shorts, made for kids, mature audience, private or not-yet-aired Premiere videos.

Does YouTube pick the thumbnail with the most clicks? No. YouTube picks the thumbnail with the highest watch time share, not the highest click-through rate.

Sources

• Test & compare thumbnails and titles, YouTube Help, read Nov 6, 2026
• YouTube creators can now test multiple video thumbnails, TechCrunch, Jun 12, 2024
• YouTube Adds Title A/B Testing And "Ask Studio" Analytics, Search Engine Journal, Sep 16, 2025
• YouTube Thumbnail Split Testing Get more views!, Freedom!, Jun 20, 2024 (video)
• A/B testing on YouTube, YouTube Creators, Dec 8, 2025 (video)
• THIS Is YouTube's NEW AB Thumbnail Testing Feature, Nick Nimmin, Feb 16, 2024 (video)