The 300-character ceiling
Bluesky posts top out at 300 characters, counted the way people read them, so an emoji counts as one. Most X posts fit without a single change. Longer ones are where the two networks part ways: by default, Twinpost splits a long post into a short Bluesky thread rather than cutting you off.
What changes, side by side
| On X | On Bluesky | What Twinpost does |
|---|---|---|
| Long post | 300 characters per post | Splits it into a thread, by default |
| Images | Up to 4 images per post | Carries your images over, by default |
| Replies, reposts, quote posts | n/a | Not mirrored by default; they stay on X |
Set it up
- Create a Twinpost account with your email.
- Connect X. This is the account Twinpost watches for new posts.
- In Bluesky, open Settings → Privacy and security → App passwords and create one for Twinpost. It is not your account password.
- Choose Bluesky in Twinpost and enter your handle and that app password.
- Start mirroring. The activity page links to each copy on Bluesky.
You can disconnect Bluesky at any time from the connect page, or delete the app password in your Bluesky settings.
Questions about Bluesky
Whose account do the posts come from?
Your own. Posts appear under the Bluesky account you connect, like anything else you write there.
What about people I mention on X?
An X handle and a Bluesky handle are different things, and the same name can belong to two different people. If it matters that someone is tagged on Bluesky, reply to the mirrored post there and tag them with their Bluesky handle.
Does it work with a custom domain handle?
Yes. Whether you are @name.bsky.social or @yourdomain.com, you connect with your handle and an app password.
Why an app password and not my normal password?
An app password is a separate password you create only for Twinpost. It is not your account password, and you can delete it at any time in Bluesky to cut Twinpost off without changing anything else.
What if I post on Bluesky directly too?
Go ahead. Twinpost only watches X, so anything you write straight on Bluesky stays there and is never copied back.