Bluesky character limits and posting rules
Last reviewed: 29 August 2026
300 graphemes, not bytes and not characters, enforced by the AT Protocol itself, so no upgrade raises it. A longer draft is split into a numbered thread rather than rejected.
What are Bluesky's limits at a glance?
The table gives the figure Postey applies for Bluesky, the field it applies to, the unit it is counted in, and whether Bluesky enforces it when a post is published.
| Field | Maximum | Counted in | Enforced at publish? |
|---|---|---|---|
| post | 300 | Graphemes | Yes, by the protocol |
How long can a Bluesky post be?
Bluesky caps a post at 300 graphemes, and Postey checks a draft against that cap before it publishes. The cap is enforced by the protocol itself, so no plan, tier or upgrade raises it.
How does Bluesky count a character?
Bluesky counts graphemes — user-perceived characters — rather than bytes or UTF-16 code units, so a family or skin-tone emoji counts as one against the 300.
What happens to a Bluesky draft that is over the limit?
Postey splits it into numbered posts that each fit 300 graphemes, charging the numbering against the budget rather than adding it afterwards. The splitting is Postey’s own — Bluesky does none, and neither does Postey’s backend outside this feature.
How does Bluesky compare with the other platforms?
Postey publishes the same draft to every platform below, reshaping it against each one's own limit rather than against Bluesky's.
| Platform | Field | Limit | Counted in | Enforced at publish? |
|---|---|---|---|---|
| X | post | 280 characters | Weighted (link 23, emoji 2) | Yes, at publish time |
| post | 3,000 characters | Code points | Yes, at publish time | |
| Threads | post | 500 characters | Code points | Yes, at publish time |
| caption | 2,200 characters | Code points | Yes, at publish time | |
| TikTok | caption | 2,200 characters | Code points | Yes, at publish time |
| YouTube | description | 5,000 characters | Code points | Field maximum only |
| post | 63,206 characters | Code points | Yes, at publish time | |
| description | 500 characters | Code points | Field maximum only |
Read the full reference for every platform Postey publishes to.