Is CopyCheck Online really free?

Yes. The Free Check uses local corpus + UAPI web search, no login needed. 3 free searches per day for guests, 10 per day when logged in.

How does the Web Check differ from Free Check?

Web Check (paid, Tavily-powered) crawls full web pages and provides deeper source matching. The Free Check is fast and great for most cases.

Yes. Click "AI Rewrite" after a check for line-by-line fixes plus a fully rewritten version (powered by DeepSeek).

No. Only check summaries and source matches are saved for your history. Raw text is never uploaded, trained on, or shared with third parties.

Mixed Chinese/English text detection. UI in English and Chinese, switchable on the fly.

Free Check uses shingle fingerprinting plus live web search. Web Check goes further with full-page extraction.

Upload a PNG or JPG and compress it to a fraction of its size with minimal quality loss.

✓ 100% free · unlimited

Compression level

3 · Balanced (default)

Output format