How to remove Claude's watermark from Slack
To send Claude-drafted Slack messages without the watermark, rewrite longer messages through a non-watermarking model before pasting, because Slack stores your exact words. Short messages carry little statistical signal; long updates and announcements carry more.
What Slack does with Claude's watermark
Slack preserves pasted text and adds no watermark. The watermark's strength scales with length, so quick replies are effectively unmarked while long posts, canvases, and announcements carry a detectable pattern.
Steps to clean it
- 1Paste your Claude text into ClaudeRewrite. It rewrites the wording through a non-watermarking model (DeepSeek V4 Flash), breaking the statistical pattern while preserving every fact, number, name and link, then strips any leftover invisible characters.
- 2Paste the cleaned text into Slack.
- 3For recurring announcements or canvases, clean once and reuse.
FAQ
Are short Slack messages watermarked?
Barely — the statistical watermark needs length to register, so brief messages carry little signal.
Remember: Claude's watermark is statistical — it lives in the word choices, so it travels with your text into Slack no matter how you paste. There is no public detector today, but published text stays checkable once Anthropic's detection API ships. See which models are marked →