BlueSky Post Specifications

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Complete guide to BlueSky post dimensions, character limits, and media specifications. Create engaging posts on the decentralized social network with perfect formatting. Updated for 2026.

Quick Specs

Dimensions
1000 × 1000px
Square (1:1)
Aspect Ratio
1:1
Recommended
Max File Size
2MB
Per image, up to 4 images per post (or 1 video instead; images and video cannot be combined)
Formats
JPG, JPEG, PNG +2
Supported formats

Dimensions & Resolution

Square (1:1)Recommended
1000 × 1000px

Maximum 1000px on longest side

Landscape (16:9)Recommended
1000 × 563px

Great for landscape photos

Portrait (4:5)
800 × 1000px

Works well for portraits

Vertical (9:16)
563 × 1000px

Vertical format supported

Important Notes

BlueSky is a decentralized social media platform built on the AT Protocol. Posts (called "skeets") support up to 300 graphemes with rich media. A post can contain text only, up to 4 images, or 1 MP4 video, but images and video cannot be combined in the same post. Images are capped at 2MB each (1000px on the longest side); video is capped at 100MB. Accepted image formats: jpeg, png, gif, webp.

Optimization Tips

  • Keep text under 300 graphemes per post
  • Images max 1000px on longest side, 2MB each
  • Add up to 4 images per post, OR 1 MP4 video (not both)
  • Accepted image formats: jpeg, png, gif, webp
  • Use alt text for accessibility
  • Profile photos are 400×400px
  • Banner images are 1500×500px (3:1 ratio)
  • Bluesky-hosted accounts must verify email before their first video upload
  • Thread posts for longer content

Sources & Verification

Last verified: 2026-05-16

300-grapheme limit, up to 4 images (2MB each, 1000px max, jpeg/png/gif/webp) OR 1 MP4 video (100MB max). Images and video cannot be combined.

Profile & Page Dimensions

avatar:400×400px
banner:1500×500px
banner Ratio:3:1
avatar Format:Square with rounded corners

Content Limits

Text Limits

Post Characters:300
Display Name:64
Bio:256
Handle:253

Media Limits

Images Per Post:4
Max Dimension:1000
Max File Size Per Image:2
Video Per Post:1
Video Format:MP4
Video Max Size M B:100
Images And Video Mutually Exclusive:
Video Requires Verified Email:first upload only, Bluesky-hosted accounts

Features

Threads:
Quotes:
Reposts:
Likes:
Lists:
Custom Feeds:
Mod Lists:

Protocol

Type:AT Protocol
Decentralized:
Portability:
Custom Domains:

Built on open AT Protocol for data portability

Algorithmic

Custom Feeds:User-created algorithms
Following:Chronological following feed
Discover:Algorithmic discover feed
Skyline:Community-curated feeds

Schedule BlueSky posts at optimal times

Auto-resize imagesAT Protocol support
Start scheduling posts

Frequently Asked Questions

What's the character limit on BlueSky?

BlueSky posts have a 300 grapheme limit, slightly longer than Twitter's original 280. You can create threads by replying to your own posts for longer content.

How many images can I add to a BlueSky post?

Up to 4 images per post. Each image must be under 2MB and no larger than 1000 pixels on its longest side. If you attach a video instead, you cannot also attach images, the two are mutually exclusive in a single post.

Can I post video on BlueSky?

Yes. A single MP4 video up to 100MB is supported per post. Bluesky-hosted accounts must have a verified email before their first video upload. There is a per-account daily ceiling of 25 videos or 10GB combined, enforced by Bluesky.

What image formats does BlueSky accept?

jpeg, png, gif, and webp. WebP gives the best compression for staying under the 2MB per-image limit; jpeg is a good default for photos; png works well for graphics with text.

Recent Updates

2026-05-16

Image limit raised to 2MB per image (was 1MB), webp added to accepted formats alongside jpeg/png/gif. Single MP4 video (up to 100MB) now supported as an alternative to images (images and video cannot be combined in the same post).

2026-01-09

Migrated to evergreen URL structure. Verified all specifications current.

2025-01-01

BlueSky maintains 300 character limit with support for up to 4 images per post

2024-11-01

Image upload quality improved with better compression algorithms

Related Specifications

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Last updated: May 16, 2026