AI 原创度 · 隐私优先

Paste Text. Check Originality Instantly.

Q: 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.

Q: Is my text stored anywhere?

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

Q: How accurate is the check?

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

Writing a blog post, product listing, essay, or social script? CopyCheck fingerprints your text against the open web in seconds — so your content never collides with what is already out there. Private, free local checks.

私密优先 —— 你的文本不会被存储、训练或分享

Blog postsProduct listingsEssaysSocial posts

Free Originality Check — Live Match Against the Web

Tip: Ctrl/⌘ + Enter to run

Or upload a file (TXT / PDF / MD)

Free Check: local corpus + live web search, no login needed. Web deep-check consumes credits.

Choose a Plan

Pay as you go, cancel anytime

Top up

Free

Start for free

Free

20 local + 3 web / month

✓Up to 5,000 chars
✓Local corpus compare
✓3 web checks/mo
✓Basic report
✓7-day history
✓Email support

Start Free

Popular

Pay As You Go

Pay per use, no subscription

$7/pack (100 credits)

$0.07 per credit (≤15,000 chars)

✓Up to 15,000 chars
✓Unlimited web checks
✓Search + crawl
✓Detailed shingle report
✓Multi-source compare
✓Lifetime history
✓API keys
✓Email support
✓No expiry

Pro

Best for heavy users

$89/mo

2,000 credits/mo (≈$0.045 each)

✓Up to 30,000 chars
✓2,000 web checks/mo
✓Unlimited local
✓Batch checks
✓PDF export
✓History + CSV export
✓High-frequency API
✓Priority support

FAQ

Quick answers about checking, rewriting, and privacy

Is CopyCheck Online really free?

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

How does the Web Check differ from Free Check?

Web Check uses Tavily deep crawl (login + credits) to extract and compare full pages — more comprehensive coverage.

Can AI rewrite my plagiarized parts?

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

Is my text stored anywhere?

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

Which languages are supported?

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

How accurate is the check?

Free Check uses shingle fingerprinting + live web search against real pages. Web Check goes further with full-page extraction.

Free Tools

Open a tool and start using it right away

Plagiarism CheckerPaste text, check originality in seconds Citation GeneratorAPA · MLA · Chicago in one click Text SummarizerAI condenses long text to bullets Grammar CheckerAI proofreads grammar & style AI RewriteStandalone paraphraser & in Free Check Image CompressorLossless PNG/JPG, 100% in browser

New here? Read what is a plagiarism checker / how to paraphrase / vs Turnitin.