YouTube thumbnail size and checker
3840 x 2160 px recommended for videos (16:9), 2160 x 3840 px for Shorts (9:16), at least 640 px on the short side, JPG or PNG. Upload a thumbnail to check it against every rule and resize it in one click.
Checks against YouTube's rules
Upload or drop an image to check its resolution, aspect ratio, file size and format against YouTube's current guidance, and to see how it reads at the small sizes viewers scroll past.
How it reads small
Approximate sizes for feeds and sidebars, not official YouTube dimensions. If the text is hard to read at the smallest size, simplify it.
Your image is processed in your browser and never uploaded anywhere. Downloads are center-cropped to the chosen shape.
YouTube thumbnail sizes at a glance
| Thumbnail | Recommended | Minimum | Aspect ratio |
|---|---|---|---|
| Video | 3840 x 2160 px | 640 px wide | 16:9 |
| Shorts | 2160 x 3840 px | 640 px tall | 9:16 |
| Podcast playlist | Not specified | Not specified | 1:1 |
| Uploading from | File size limit | Formats |
|---|---|---|
| Computer | 50 MB for video, Shorts and podcast thumbnails | JPG or PNG |
| Phone | 2 MB for video thumbnails, 10 MB for podcasts | JPG or PNG |
Source: YouTube Help, Add custom thumbnails, checked 31 October 2026.
Why most guides still say 1280 x 720
Most top-ranking guides still give 1280 x 720 and 2 MB as the YouTube thumbnail size. YouTube's current help page recommends 3840 x 2160 for videos and 2160 x 3840 for Shorts, and raises the limit to 50 MB when you upload from a computer. The 2 MB limit now applies only to uploads from a phone.
1280 x 720 still matters in one place: A/B testing. If any thumbnail in a test is below 720p, YouTube downscales every thumbnail in that test to 854 x 480 (YouTube Help). Treat 1280 x 720 as the floor and 3840 x 2160 as the target.
Shorts thumbnails work differently
Custom Shorts thumbnails use a vertical 9:16 image and can currently only be added in YouTube Studio on a computer. If a vertical video has a 16:9 custom thumbnail, YouTube replaces it with an auto-generated 4:5 thumbnail on the home, explore and subscription pages, though your custom image still appears in the watch feed and history.
Before you upload: a quick checklist
- Verify your YouTube account; custom thumbnails need it.
- Export at 3840 x 2160 (or 2160 x 3840 for Shorts), as JPG or PNG.
- Check it at a small size: a thumbnail is usually seen far smaller than you design it, so keep text short and large.
- If you upload from a phone, keep the file under 2 MB.
- For important videos, A/B test up to three versions, all at 1280 x 720 or larger.
Size gets a thumbnail accepted; design gets it clicked. Our guide to thumbnail strategy and click-through rate covers what makes viewers click, and our thumbnail design service produces them on brand for every video. For channel art, see the YouTube banner size tool.
Frequently asked questions
What is the YouTube thumbnail size in 2026?
YouTube recommends 3840 x 2160 pixels for video thumbnails (16:9) and 2160 x 3840 for Shorts (9:16). The minimum is 640 pixels wide for videos and 640 pixels tall for Shorts. Upload a JPG or PNG.
Is 1280 x 720 still the right YouTube thumbnail size?
It still works, and it is the threshold that matters for A/B testing: if any test thumbnail is below 1280 x 720, YouTube downscales all of them to 854 x 480. But YouTube's current recommendation is 3840 x 2160, so make thumbnails larger when you can.
What is the maximum file size for a YouTube thumbnail?
It depends on how you upload. From a computer the limit is 50 MB for video, Shorts and podcast thumbnails. From a phone it is 2 MB for video thumbnails, or 10 MB for podcasts.
What size is a YouTube Shorts thumbnail?
YouTube recommends 2160 x 3840 pixels at a 9:16 aspect ratio, at least 640 pixels tall. Custom Shorts thumbnails can currently only be added in YouTube Studio on a computer.
Why can't I upload a custom thumbnail?
Custom thumbnails need a verified YouTube account. Verify your account in YouTube Studio, then the upload option appears under Thumbnail in each video's details.
Can I A/B test YouTube thumbnails?
Yes. YouTube lets you test and compare up to three thumbnails, titles, or title and thumbnail combinations on a video. Shorts, scheduled lives and premieres cannot be A/B tested.
What aspect ratio should a YouTube podcast thumbnail be?
1:1 square for podcast playlists, instead of 16:9. YouTube does not publish a pixel size for these; 2160 x 2160 gives plenty of resolution.