YouTube Thumbnail Size: Official Specs and Tips
The current thumbnail specs for videos and Shorts from YouTube’s Help Center, how to upload and test thumbnails, and what gets removed.
In short: YouTube recommends custom thumbnails of 3840 × 2160 pixels (16:9) for videos and 2160 × 3840 pixels (9:16) for Shorts, at least 640 pixels wide (videos) or tall (Shorts), in an image format such as JPG or PNG, under 2 MB from a phone or 50 MB from a computer. You need a verified account, and you can A/B test up to 3 thumbnails in YouTube Studio.
Last reviewed: 6 October 2026
The short answer
YouTube’s own Help Center recommends that custom thumbnails:
- are 3840 × 2160 pixels for videos (16:9) and 2160 × 3840 pixels for Shorts (9:16);
- are at least 640 pixels wide for videos, or at least 640 pixels tall for Shorts;
- are uploaded as an image file such as JPG or PNG;
- stay under 2 MB when uploading from a phone (10 MB for podcasts) or 50 MB from a computer.
Podcast playlists use a square 1:1 thumbnail instead. All of this comes from Add custom thumbnails on YouTube, checked on 6 October 2026.
Older guides often say 1280 × 720 pixels. That still works as a 16:9 image, but YouTube now recommends 3840 × 2160 and says thumbnails should be “as large as possible”. In its A/B testing tool, YouTube downscales all test thumbnails to 854 × 480 if any of them is below 1280 × 720.
YouTube thumbnail specs at a glance
| Spec | Long-form videos | Shorts |
|---|---|---|
| Recommended size | 3840 × 2160 px | 2160 × 3840 px |
| Aspect ratio | 16:9 | 9:16 |
| Minimum | 640 px wide | 640 px tall |
| File types | Image formats such as JPG or PNG | Image formats such as JPG or PNG |
| Max file size | 2 MB on mobile, 50 MB on desktop | 50 MB on desktop |
| Where to upload | YouTube Studio (computer or app) | YouTube Studio on a computer only |
| Account requirement | Verified account | Verified account |
Source: YouTube Help: Add custom thumbnails. Podcast playlists: 1:1 thumbnail; podcast uploads from mobile up to 10 MB.
Who can upload a custom thumbnail?
YouTube says you can choose from auto-generated options, or upload your own if your account is verified. Verification usually means confirming a phone number, which unlocks YouTube’s intermediate features (feature access for YouTube creators).
A few other limits to know:
- Daily limit: there is a limit on how many custom thumbnails a channel can upload per day. If you see “Daily custom thumbnail limit reached”, try again in 24 hours. YouTube says limits vary by country or region and channel history.
- Strikes affect it: Community Guidelines strikes affect how many custom thumbnails you can upload, and repeat offences can remove custom thumbnail access for 30 days.
- Shorts: custom Shorts thumbnails can currently only be added in YouTube Studio on a computer.
Setting up a new channel? Our guide on how to start a YouTube channel covers verification step by step.
How to upload a custom thumbnail
For a video (YouTube Help):
- Sign in to YouTube Studio.
- From the left menu, select Content.
- Open the video you want to edit.
- Below Thumbnail, click Upload file (or Get suggestions to generate options).
- Click Save.
For a Short: in YouTube Studio on a computer, go to Content, then the Shorts tab, open the Short, and upload a file below Thumbnail. YouTube recommends a 9:16 image.
YouTube notes that thumbnail changes can take time to appear. It also mentions that, for vertical videos with a 16:9 custom thumbnail, an auto-generated 4:5 thumbnail may be shown on the home, explore and subscription pages.
Design a thumbnail that gets the right clicks
YouTube’s rules tell you what’s allowed; the design is up to you. These practical habits work for most channels:
- One clear subject. A face, a product or a result, large enough to read on a small phone screen.
- Few words. Three to five big words at most, or none if the image says it.
- High contrast. Bright subject on a simple background; avoid busy scenes.
- Works with the title. Thumbnail and title should add to each other, not repeat the same words.
- Consistent style. Similar colours, fonts and layout so viewers recognise your videos.
- Keep the bottom-right clear. YouTube shows the video length there on many screens.
- Honest. It must show something that is actually in the video (see the policy below).
Need title ideas to pair with your thumbnail? Try our free YouTube title generator.
Test thumbnails with YouTube’s A/B tool
YouTube Studio lets eligible creators test and compare up to 3 titles and thumbnails (A/B test titles and thumbnails). At the end of the test, the option with the highest watch time is shown to all viewers. Key points from YouTube Help:
- It is available on computers in YouTube Studio, and you need advanced features enabled.
- You can’t A/B test Shorts, scheduled Lives or Premieres (Premieres become eligible after they end), or videos made for kids, for mature audiences or private videos.
- Tests usually finish within two weeks; changing the title or thumbnail during a test stops it.
- Results can be “Winner”, “Performed Same” or “Inconclusive”. If there is no clear winner, the first option you uploaded is used.
- YouTube suggests testing older videos first, and testing options that are clearly different from each other.
YouTube optimises these tests for watch time rather than click-through rate, so a thumbnail that gets clicks but disappoints viewers won’t win.
Thumbnail rules: what gets removed
Thumbnails must follow YouTube’s Community Guidelines. The Thumbnails policy says not to post a thumbnail that shows, among other things, pornographic or sexually gratifying imagery, violent imagery intended to shock or disgust, graphic gore, vulgar language, or a thumbnail that misleads viewers to think they’re about to view something that’s not in the video.
YouTube may age-restrict a video or remove a thumbnail that isn’t suitable for all audiences without issuing a strike. Thumbnails that violate other policies can be removed and lead to a warning or strike. Copying another channel’s branding to impersonate them isn’t allowed either.
Common thumbnail mistakes
- Uploading tiny images. Start at 3840 × 2160 (or at least 1280 × 720) so the image stays sharp on TVs.
- Wrong shape for Shorts. Use a 9:16 image for Shorts thumbnails.
- Too much text, which becomes unreadable on phones.
- Important elements in the corner where the timestamp sits.
- Clickbait that the video doesn’t deliver. It can break YouTube’s policy, and viewers leave quickly.
- A new style for every video, so subscribers don’t recognise your uploads.
- Never checking results. Compare impressions click-through rate and watch time in YouTube Analytics.
Quick thumbnail workflow
- Decide the one idea the video delivers, in a few words.
- Capture a strong still while filming (a reaction, a before and after, the finished result).
- Design at 3840 × 2160 (or 2160 × 3840 for Shorts) and export as JPG or PNG under 50 MB.
- Check it at a small size, as it would appear on a phone home feed.
- Upload in YouTube Studio and, for important videos, set up an A/B test with two or three clearly different options.
- Review results after the test and reuse the winning patterns.
Our social media image size guide also covers YouTube banners and profile pictures, with a free resize tool.
Making Shorts? Our YouTube Shorts size guide covers the 9:16 video export, the Shorts thumbnail and the safe zone.
Want thumbnails and videos handled for you?
We plan, edit and publish YouTube videos and Shorts, including titles, thumbnails and descriptions. Start with a free social media audit or ask for a custom quote. If you prefer chat, message us on WhatsApp at +91 8827409728. See our YouTube management service and YouTube Shorts agency.
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Frequently Asked Questions
What size is a YouTube thumbnail?
YouTube recommends 3840 × 2160 pixels (16:9) for videos and 2160 × 3840 pixels (9:16) for Shorts, with a minimum width of 640 pixels for videos and a minimum height of 640 pixels for Shorts.
Is 1280 × 720 still OK for YouTube thumbnails?
It is still 16:9 and will upload, but YouTube now recommends 3840 × 2160 and says thumbnails should be as large as possible. In A/B tests, a thumbnail below 1280 × 720 causes all test thumbnails to be downscaled to 854 × 480.
What is the maximum file size for a YouTube thumbnail?
2 MB when uploading from a phone (10 MB for podcasts) and 50 MB from a computer, according to YouTube Help.
Why can’t I upload a custom thumbnail?
YouTube requires a verified account for custom thumbnails. You may also have hit the daily custom thumbnail limit, or Community Guidelines strikes may have limited the feature.
Can I add a custom thumbnail to a YouTube Short?
Yes, in YouTube Studio on a computer. YouTube recommends a 9:16 image for Shorts thumbnails.
How many thumbnails can I A/B test?
Up to 3 titles and thumbnails per video in YouTube Studio on a computer. The option with the highest watch time is shown to all viewers when the test ends.
Which file format is best for YouTube thumbnails?
YouTube lists image formats such as JPG or PNG. Use whichever keeps the image sharp within the file size limit.
Want thumbnails, titles and videos handled for you?
We plan, edit and publish YouTube videos and Shorts with thumbnails that follow YouTube’s specs. Get a free audit or a custom quote, or message us on WhatsApp.
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