Reel size checker

What the checker looks at

• Shape. Whether the frame is 9:16, the vertical shape that fills a phone screen.
• Resolution. Whether there are enough pixels to look sharp, and whether there are more than the apps will use.
• Frame rate. Whether it is in the normal range of 24 to 60 frames per second.
• Format. The container and the video and audio codecs inside it.
• Length. Compared with each app's limit.
• File size. Whether the upload is likely to struggle on mobile data.

The report uses three labels. Good means nothing to do. Check means it will probably upload, but you may not get the result you want. Fix means change it before uploading.

What the apps expect

The three apps agree on the basics, so one export works for all of them.

They differ on length.

Length limits were last checked in October 2026. The YouTube figure comes from YouTube Help. Instagram and TikTok have both changed their limits several times and roll changes out gradually, so the figures marked “reported” come from third-party guides and your account may differ.

Fixing what it finds

• Too large, or bigger than 1080p: use the video compressor and choose 1080p.
• Too long: cut it with the video trimmer.
• Unusual codec: the compressor always saves H.264, so running the video through it also converts it.
• Wrong shape: reframe it in your editing app. Cropping is a creative choice, so this site does not do it for you.

Questions

What size should an Instagram Reel be?

1080 × 1920 pixels, which is a 9:16 vertical frame. YouTube Shorts and TikTok use the same size.

My video is 4K. Should I shrink it before uploading?

Usually yes. Instagram and TikTok play short vertical video at up to 1080 pixels wide, so the extra detail is thrown away and the upload takes several times longer. Compressing to 1080p first gives the same result on screen.

Why does the checker say “Check” for a long video?

Because the answer depends on your account and on the date. Instagram and TikTok have raised their limits more than once and do not switch every account at the same moment. The checker tells you where the uncertainty is so you can look in the app.

Does it tell me if my video will go viral?

No. It checks technical details only: whether the file is the right shape, size and format.

Last reviewed 10 October 2026.