GPT Cleanup

Free Claude AI Detector

Detect if text was generated by Anthropic's Claude AI by scanning for hidden Unicode markers, invisible formatting, and technical fingerprints.

100% client-side · No text is ever sent to a server · Works with all Claude versions

Text to Analyze
Detection Result

Scan results will appear here...

How this works: This tool scans for technical fingerprints — hidden Unicode characters, HTML attributes, and formatting markers that AI chat interfaces inject into copied text. It does not analyze writing style or use machine learning. A low score means no technical markers were found, but the text could still be AI-generated and manually cleaned. A high score means definitive technical evidence of AI tool origin.

How Claude AI Detection Works

Anthropic's Claude generates text through its web interface at claude.ai, which uses a rich-text rendering system to display responses. When you copy text from Claude, the interface's rendering engine may embed invisible Unicode characters — zero-width spaces, non-breaking spaces, word joiners, and other hidden markers — into the copied text.

While Claude doesn't inject the same proprietary HTML attributes that ChatGPT does, its text output often contains patterns of Unicode characters that differ from human-typed text. Our detector scans for all known categories of AI markers across 10 detection categories, identifying evidence from Claude and every other major AI tool.

Claude is known for its distinctive writing style — clear structure, balanced arguments, and measured tone. While our tool focuses on technical markers rather than writing style, the combination of invisible characters and Claude's characteristic formatting patterns provides strong detection capability for text copied directly from claude.ai.

Frequently Asked Questions

Common questions about detecting Claude AI text

Can you detect text written by Claude?
Yes. When you copy text from Claude's web interface (claude.ai), the clipboard often contains hidden Unicode characters — zero-width spaces, non-breaking spaces, and other invisible markers that Claude's rendering engine injects. Our detector scans for these technical fingerprints with 100% accuracy.
How is Claude's fingerprint different from ChatGPT's?
ChatGPT has unique HTML data attributes (data-start, data-end) that Claude doesn't use. However, Claude's web interface still injects zero-width characters, non-breaking spaces, and other Unicode markers during copy operations. The pattern and frequency of these markers differs between tools, and our detector identifies markers from both.
Does this work with Claude API output?
API responses from Claude typically contain fewer hidden markers since there's no web UI involved in generating the text. However, the text may still contain formatting patterns like smart quotes, em dashes, and Unicode ellipsis that our detector identifies. For the strongest detection results, scan text copied directly from claude.ai.
Which versions of Claude does this detect?
Our detector works with text from all Claude versions — Claude 3 Opus, Claude 3.5 Sonnet, Claude 3 Haiku, and any future versions. The hidden characters come from Claude's web interface rendering, not the model itself, so detection works regardless of which Claude model generated the text.

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Remove Claude AI Fingerprints

Found markers? Clean them all in one click with our Text Cleaner — removes hidden characters and invisible formatting instantly.