Bluesky Post Size and Specs (2026)
Every Bluesky limit below comes from the rules PostQuest uses to check posts before they publish. Publishing limits were last verified on .
- Main post size
- Up to 1 MB
- Photo Post
- Caption limit
- 300 graphemes
- Avatar
- PNG or JPEG, up to 1 MB
Bluesky image and video specs
Text Post and Link Post use only the caption limit, so they have no media table.
Photo Post1 file
| Spec | Image |
|---|---|
| File size | Up to 1 MB |
| Formats | JPEG, PNG, WebP |
Carousel Post2–4 files
| Spec | Image |
|---|---|
| File size | Up to 1 MB |
| Formats | JPEG, PNG, WebP |
Video Post1 file
| Spec | Video |
|---|---|
| File size | Up to 100 MB |
| Length | 1 s–3 min |
| Formats | MP4, MOV |
- Supports up to 20 WebVTT caption files of 20,000 bytes each.
Bluesky caption and hashtag limits
Caption limit
300 graphemes
- Bluesky counts graphemes, so an emoji costs one character.
Hashtags
No hard limit
- No official hashtag-count limit.
- Bounded by the 300-character post limit.
Accounts that can publish
Any authenticated AT Protocol repository account.
Bluesky profile and banner sizes
| Image | Size | Details | Source |
|---|---|---|---|
| Avatar | PNG or JPEG, up to 1 MB | The profile lexicon sets file type and size, not pixel dimensions. | Bluesky lexicon: app.bsky.actor.profileVerified October 4, 2026 |
| Banner | PNG or JPEG, up to 1 MB | The profile lexicon sets file type and size, not pixel dimensions. | Bluesky lexicon: app.bsky.actor.profileVerified October 4, 2026 |
Bluesky specs FAQ
What size should a Bluesky post be?
A Bluesky photo post must meet these limits: file size up to 1 MB. No fixed pixel dimensions apply to this format.
What is the Bluesky character limit?
Bluesky captions can be up to 300 graphemes long. Bluesky counts graphemes, so an emoji costs one character.
How many hashtags can you use on Bluesky?
Bluesky has no hard hashtag limit. Bounded by the 300-character post limit.
What size is the Bluesky avatar?
PNG or JPEG, up to 1 MB. The profile lexicon sets file type and size, not pixel dimensions.
Sources
Publishing limits last verified against official API documentation. Profile sizes last verified .
More platform specs
Schedule posts that pass these checks
PostQuest validates every caption and file against these limits before a post is scheduled, so nothing fails at publish time.