Remove Claude’s formatting from Substack
Substack preserves pasted HTML, so copying straight from Claude carries its class names — the ones containing “claude” — into a Substack post. They are invisible while you read, but present in the source and readable by anyone who looks. Paste into a plain-text editor first, then into Substack.
Check yours first. Paste the text into the free checker and it lists every artifact with its exact position — no account, nothing uploaded, unlimited.
Check my text →What Substack keeps
- Substack's editor keeps some pasted formatting, and the published post is public HTML.
- Email versions are generated from the same source, so anything left in the post also ships to every subscriber's inbox.
The fastest fix
Paste into a plain-text editor first, then into Substack.
That handles the markup. It does not handle zero-width characters, non-breaking and exotic spaces, smart quotes or em dashes — those are text rather than formatting, so they survive the paste route above and every other one.
How to check it worked
Open the published post and use View Source. Also send yourself a test email, because the email build is generated separately from the web version.
