PostEaseThe short answer
A Bluesky post can be up to 300 characters, counted the way you see them, so an emoji or an accented letter counts as one. A post can carry up to 4 images of up to 2 MB each, or one MP4 video.
Since 26 August 2026, videos can be up to 10 minutes long, after an earlier rise in the maximum file size to 300 MB. A video can carry caption files, up to 20 of them, in WebVTT. These limits come from Bluesky’s announcements and the AT Protocol’s own definitions of a post.
Every limit, at a glance
These are the limits written into Bluesky’s post format and announced by Bluesky.
| What | Limit | Note |
|---|---|---|
| Text | 300 characters, counted as you see them | Also capped at 3,000 bytes |
| Images per post | Up to 4 | |
| Image file size | Up to 2 MB (2,000,000 bytes) each | |
| Video | One MP4 per post | |
| Video length | Up to 10 minutes | Since 26 August 2026 |
| Video file size | Up to 300 MB | |
| Video captions | Up to 20 WebVTT files | Up to 20 KB each |
| Hidden tags | Up to 8 per post | Up to 64 characters each |
How Bluesky counts characters
Bluesky counts graphemes, the characters as you see them on screen, up to 300. An emoji built from several code points, such as a family or a flag, counts as one, unlike on X, where an emoji counts as two. There is also a hidden ceiling of 3,000 bytes, which only matters for text made almost entirely of complex characters.
| Platform | Limit | How an emoji counts |
|---|---|---|
| Bluesky | 300 characters | As 1 |
| X | 280 characters | As 2 |
| Threads | 500 characters | By its size in bytes |
Images
Attach up to 4 images to a post, each up to 2,000,000 bytes. That is 2 MB in decimal terms, slightly less than 2 MiB, so an image a few percent over 2 MB on your computer may be refused. Every image can have alt text describing it for people using screen readers.
Video
A post can carry one MP4 video. Bluesky raised the maximum file size to 300 MB and then, on 26 August 2026, the maximum length to 10 minutes, with uploads it says are two to three times faster. A video can have up to 20 caption files in WebVTT format, for different languages.
Questions
What is the Bluesky character limit?
300 characters per post, counted as graphemes, the characters as you see them, so an emoji counts as one.
How long can a Bluesky video be?
Up to 10 minutes, since Bluesky raised the limit on 26 August 2026, and up to 300 MB.
How many images can a Bluesky post have?
Up to 4, each up to 2 MB (2,000,000 bytes).
What happens if my image is over 2 MB?
Bluesky refuses images over 2,000,000 bytes, so resize or compress it below that before posting. A photo saved at a lower JPEG quality or a smaller size usually fits with no visible difference.
Can I add captions to a Bluesky video?
Yes. A video can carry up to 20 WebVTT caption files, each up to 20 KB.
Sources
- Bluesky, Video update: up to 10 minutes and faster uploads, August 2026.
- Bluesky, app.bsky.feed.post, app.bsky.embed.images and app.bsky.embed.video lexicons, checked October 2026.