Text hygiene for the AI age
No hidden characters.
No invisible junk.
Paste any text — especially output from ChatGPT, Claude, or copied from the web — and instantly find every hidden Unicode and zero-width character. Then clean them with one click.
Clean text in three simple steps
Paste
Drop in AI output, a web copy, or a document — plain text only, nothing leaves your browser.
Scan
NoAtMark highlights every invisible & zero-width character and names each one (U+200B, ZWJ, BOM…).
Clean
One click strips the hidden artifacts and copies clean text — ready for editors, forms, code, or CMS.
Built for every workflow
💻 Code & validation
Hidden bytes silently break string matching and form validation. Clean before you debug.
📊 CSV & data
Invisible characters corrupt CSV/JSON exports and kill imports. Strip them first.
📝 CMS & publishing
Paste AI drafts into WordPress or your CMS clean — no invisible content, no layout surprises.
🎯 SEO & content
Editors, notepads, and draft tools inject invisible chars. Clean before you ship.
🔍 QA & testing
Trojan-Source style characters can hide inside copied test data. Catch them before they bite.
🤖 AI output
ChatGPT & Claude copies often carry zero-width joiners and BOMs. This is what NoAtMark was made for.
NoAtMark, everywhere you write
Copying from an AI tool shouldn't mean carrying invisible baggage. The browser extension cleans as you paste.
🌐 Chrome extension free
Automatically strip invisible characters the moment you copy from ChatGPT, Claude, or any web page. Install →
🗂️ C2PA Checker
Images are marked too. Drop a file in the C2PA Checker to see if it carries Content Credentials.
What NoAtMark is — and isn't
✓ It cleans invisible characters
Zero-width spaces (U+200B), joiners, BOMs, direction marks, variation selectors — the hidden Unicode bytes that break validation, matching, and layout.
✗ It can't remove AI watermarks
Claude's text watermark is a statistical signal in word choice, not a character. C2PA lives in file metadata. Neither is something this tool — or any tool — strips today. Why →
Simple, transparent pricing
Scanner
$0 forever
- ✓ Invisible character scanner & cleaner
- ✓ 19+ character types detected
- ✓ 100% private, unlimited text
Humanize coming soon
$9 /mo
- ✓ Natural rewriting with tone control
- ✓ Academic, business & casual tones
- ✓ Clean, artifact-free output
Understand the AI watermark era
Claude's text watermark
What it is — and what can & can't be removed. →
Zero-width characters
U+200B, ZWJ, BOM — the invisible bytes. →
C2PA & Content Credentials
The signed-provenance standard, explained. →
C2PA Checker
Verify provenance in your images. →
AI watermark glossary
Every term in one place. →
Humanize AI text
Natural rewriting, coming soon. →
Frequently Asked Questions
What are zero-width characters?
Zero-width characters are Unicode code points that occupy no visible space, like the zero-width space (U+200B), zero-width joiner (U+200D), and zero-width non-joiner (U+200C). They're invisible on screen but still count as characters, breaking validation, searching, and layout.
Why does AI-generated text have hidden characters?
AI models, text editors, and copy-paste from web pages can silently insert zero-width characters, BOMs, soft hyphens, and variation selectors. The output looks fine but carries invisible artifacts.
Does NoAtMark remove Claude's watermark?
No, and no tool honestly can today. Anthropic's text watermark is a statistical signal in word choice, not a visible character; C2PA lives in file metadata. NoAtMark removes invisible Unicode characters — it doesn't claim to strip statistical watermarks.
Is NoAtMark free?
The scanner and cleaner are free forever — no sign-up, no uploads, no limits. Humanize will have a free tier and a paid subscription.
Can I clean invisible characters in bulk?
A WordPress plugin and REST API for cleaning an entire site's content before publishing are on the roadmap.