Free tool
Bluesky video and image limits (2026)
Bluesky's official limits for Bluesky images and Bluesky videos, checked 2026-10-21, plus a free checker for your file.
Last checked against each network's documentation on .
Limits
What Bluesky accepts
Every rule below is quoted from the network's own developer or help page, linked beside it. Where a network's API reference and its help centre disagree, the API reference wins, because that is what a scheduler publishes through.
| Rule | Source |
|---|---|
| Any image type. | Bluesky AT Protocol lexicon: app.bsky.embed.images, checked 2026-10-21 |
| At most 2 MB (2,000,000 bytes) per image. | Bluesky AT Protocol lexicon: app.bsky.embed.images, checked 2026-10-21 |
| Rule | Source |
|---|---|
| MP4. | Bluesky AT Protocol lexicon: app.bsky.embed.video, checked 2026-10-21 |
| At most 300 MB (300,000,000 bytes). | Bluesky AT Protocol lexicon: app.bsky.embed.video, checked 2026-10-21 |
| Up to 3 minutes. | Bluesky's official account (@bsky.app), 2025-03-10, checked 2026-10-21 |
Character and attachment limits for Bluesky are on the Bluesky page.
Questions
Media limits, answered
What is the maximum file size for a Bluesky image?
At most 2 MB. Bluesky states: "At most 2 MB (2,000,000 bytes) per image." Source: Bluesky AT Protocol lexicon: app.bsky.embed.images, checked 2026-10-21.
What file types does Bluesky accept for a Bluesky image?
any image file. Bluesky states: "Any image type." Source: Bluesky AT Protocol lexicon: app.bsky.embed.images, checked 2026-10-21.
How long can a Bluesky video be?
At most 3 min. Bluesky states: "Up to 3 minutes." Source: Bluesky's official account (@bsky.app), 2025-03-10, checked 2026-10-21.
What is the maximum file size for a Bluesky video?
At most 300 MB. Bluesky states: "At most 300 MB (300,000,000 bytes)." Source: Bluesky AT Protocol lexicon: app.bsky.embed.video, checked 2026-10-21.
What file types does Bluesky accept for a Bluesky video?
MP4. Bluesky states: "MP4." Source: Bluesky AT Protocol lexicon: app.bsky.embed.video, checked 2026-10-21.
Requirements by network
Run it from code
The same check is a free API: send the file's metadata, never the file. No key, JSON by default, Markdown with Accept: text/markdown.
curl -s "https://usepostify.com/api/tools/validate-media?type=video/mp4&bytes=48000000&width=1080&height=1920&duration=42"
Then schedule it in Postify
Once the file fits, Postify publishes it to every network from one composer, each with its own caption. There is a free plan with no credit card required.