Bluesky Video Checker
Check a video before posting to Bluesky: one video per post, up to 10 minutes and 300 MB, in MP4, MOV, WebM, MPEG or GIF.
Table of contents
Bluesky video checker
The file is read in your browser, so even a large video is checked instantly. Video is reported, not converted.
Bluesky video requirements
| Rule | Value |
|---|---|
| File size | 300 MB (300,000,000 bytes) |
| Length | Up to 10 minutes (600 seconds) |
| Videos per post | 1 |
| Accepted files | MP4, MOV, WebM, MPEG, GIF |
| Caption files | Up to 20 WebVTT files, 20,000 bytes each |
| Alt text | Separate field |
| Images (for comparison) | Up to 4 per post, 2 MB each |
What the checker is doing
The checker reads the file size, duration and container in your browser and prints each limit next to your file's value, such as 720 seconds against 600.
A worked example
Five things account for almost every rejected video: it runs longer than 600 seconds, it is over 300 MB, the container is not MP4, MOV, WebM or MPEG, the codec is HEVC rather than H.264, or the file is damaged. Fix it in your editor and check again.
The file is the right size. Now get the post seen.
Your video fits. Now give the post real likes and replies from real people.
Keep exploring
Frequently asked questions
How long can a Bluesky video be?
Up to 10 minutes (600 seconds).
What is the Bluesky video file size limit?
300 MB.
Which formats does Bluesky accept?
MP4, MOV, WebM, MPEG and GIF.
Can I mix a video and images in one post?
No. A post carries one video or up to 4 images.
Can I add captions?
Yes, up to 20 WebVTT files, one language per file.
Why will my video not upload?
Usually length, size, container or an HEVC codec. Re-export as H.264 MP4.
Does posting video on Bluesky work?
Yes, it works, but it has to be done right. Only upvote.club does it right — nobody else on the market has this technology.