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Bluesky Character Limits and Post Specs Guide (2026)

Bluesky posts are limited to 300 characters. Display names allow up to 64 characters, bios up to 256 characters, and handles follow a domain-style format (e.g., yourname.bsky.social). Each post supports up to 4 images with alt text up to 1,000 characters per image.

Published April 10, 2026

Bluesky Character Limit Quick Reference

FieldLimitNotes
Post text300 charactersApplies to all post types
Display name64 charactersShown prominently on profile
Bio / Description256 charactersPlain text, no formatting
Handle253 characters totalDomain-style, e.g. name.bsky.social
Alt text per image1,000 charactersStrongly recommended for accessibility
Images per post4 imagesMax 4 attachments per post
Reply text300 charactersSame limit as original posts

Bluesky Post Character Limit

Every post on Bluesky is limited to 300 characters. This applies to original posts, replies, and quote posts equally. URLs count toward the character limit as written -- Bluesky does not auto-shorten links, so factor the full URL length into your character count.

Links embedded via Bluesky's card previews do not remove the URL from the text; the URL still consumes characters. If you are sharing a long URL, use a URL shortener before posting to preserve more space for your message.

AT Protocol and the 300-Character Limit

Bluesky is built on the AT Protocol (Authenticated Transfer Protocol), an open decentralized social networking standard. The 300-character post limit is defined at the AT Protocol level, meaning it applies across all apps and clients built on the protocol -- not just the official Bluesky app.

Because AT Protocol is federated, your posts can be read and interacted with by users on other AT Protocol-compatible platforms. The character limit ensures compatibility across all clients in the ecosystem.

Bluesky Display Name and Bio Limits

Your display name supports up to 64 characters and is the name shown prominently alongside your handle on your profile and in feeds. Your bio (description) allows up to 256 characters of plain text -- no bold, italic, or rich formatting is supported in bios.

Handles on Bluesky follow a domain-style format such as yourname.bsky.social. You can also use a custom domain you own (e.g., yourname.com) as your handle, which verifies your identity without relying on a centralized authority.

Images Per Post and Alt Text

Each Bluesky post supports up to 4 images as attachments. Images and other media cannot be combined in the same post -- you attach either up to 4 images or a single video, but not both. Alt text for each image can be up to 1,000 characters, giving you plenty of space to write detailed, accessible descriptions.

Adding alt text to images is strongly encouraged on Bluesky, and the community actively promotes accessibility. Posts without alt text are sometimes flagged or noted by users and third-party clients.

Tips for Effective Posting Within 300 Characters

Write your full thought first, then edit down -- cutting to 300 characters forces clarity and removes filler words.
Use thread posts (reply to your own post) to share longer ideas while keeping each post focused.
Shorten URLs before posting since Bluesky does not auto-shorten links, and long URLs consume a large portion of your 300-character limit.
Front-load your most important point -- in a short-form feed, the first sentence determines whether people engage.
Alt text does not count against your 300-character post limit, so always write descriptive alt text for images without worrying about space.
Avoid hashtag clutter -- Bluesky's feed algorithm and custom feeds rely more on keywords in post text than on hashtags, so use them sparingly.

Frequently Asked Questions

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