Writing the post
The editor, formatting, mentions, emoji and character counts
Where: Inside the composer, the left column
The editor changes per platform
Postiz offers different formatting depending on what the selected platform accepts. You are not seeing an inconsistent interface, you are seeing what that platform can carry.
| Editor | Toolbar | Used by |
|---|---|---|
| Plain | Emoji and signature only | Platforms that render text as-is |
| Standard | Bold, underline, emoji, signature | Most social platforms |
| Markdown | Adds links, bullet lists, headings H1 to H3 | Discord, Medium, Dev.to, Hashnode, Whop |
| HTML | Rich formatting | X, WordPress, Listmonk |
Telegram is a special case: it takes markdown but not headings, so the heading buttons are hidden.
Character counts
The counter under the editor shows the limit for the selected channel, and it is media-aware, so attaching an image can change the number on platforms that charge characters for links or media.
Limits vary enormously: Bluesky 300, X 280 (4,000 verified, 100,000 in article mode), Mastodon 500, LinkedIn 3,000, Facebook 63,206. The full list is in Posting rules by platform.
If you are over the limit on one channel only, detach that channel rather than cutting the text everywhere. See Global vs per-channel.
Mentions
Type @ to mention someone. Postiz queries the platform for matching
accounts and inserts a real mention, not just text.
Mentions only work on a detached channel. In the Global tab there is no single platform to resolve the handle against, so the suggestion list does not appear.
Emoji
The emoji picker sits in the toolbar and follows your light or dark theme. You can also paste emoji directly.
Signatures
The signature button inserts a saved block of text. If one of your signatures is marked auto-add, it is already in the editor when the composer opens.
Manage them in Settings, see Sets and signatures.
Links
Postiz validates links as you type and rejects ftp:, file: and mailto:
schemes, plus anything that looks like a bare email address.
What happens to the links you do add depends on your short link preference and the platform. See Links and validation.
Undo
The editor keeps 100 steps of undo history. Closing the composer discards everything, so save a draft if you are not finished.