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Writing & Translation

Copyleaks

Checks text for AI writing and plagiarism in one scan, in over 30 languages.

3.9our rating
FreemiumFrom $0Works with Claude Code
Visit website Compare

Quick take

  • One scan shows both AI-written passages and copied text, with sources.
  • The best language coverage of the big detectors, and it catches plagiarism translated from another language.
  • Personal is $13.99 a month billed yearly for about 25,000 words a month. Pro jumps to $74.99.
  • Very similar to Originality.ai. Pick Copyleaks for languages and schools, Originality.ai for SEO content at volume.
  • No detector is proof, so treat flags as a reason to ask questions.

What is Copyleaks?

Copyleaks checks writing for two things at once: whether it was written by AI and whether it was copied. Paste text, upload files or scan a whole website, and you get one report showing AI-written passages and matching sources. It works in more than 30 languages for AI detection and over 100 for plagiarism, and it can catch text that was copied from one language and translated into another.

It also checks whether images were made by AI, works inside Google Docs and as a browser extension, and lets you run scans from Claude through MCP (a connector that lets Claude use another app). Schools connect it to Canvas, Moodle and Blackboard, and big companies use its API.

The catch: it overlaps heavily with Originality.ai, which is cheaper for high volumes of web content. Like every detector, it sometimes flags human writing as AI, whatever accuracy figures the marketing quotes. Switching plans wipes your unused credits, and refunds are hard to get.

Who's using it, and who it's for

  • Schools and universities
  • Publishers
  • Content agencies
  • Compliance teams
  • Students

Schools, publishers and businesses that need AI and plagiarism checks together, especially across several languages.

Key features

  • AI and plagiarism in one report

    Shows AI-written passages and copied text with matching sources in a single scan.

  • Many languages

    AI detection in 30+ languages and plagiarism checks in 100+, including translated plagiarism.

  • AI image detection

    Checks whether an image was made by AI.

  • Website scans

    Upload a sitemap to check every page of a site at once (Pro).

  • Works where you are

    Chrome, Edge and Firefox extensions, a Google Docs add-on, and MCP access from Claude.

  • API and school integrations

    Plug it into Canvas, Moodle, Blackboard or your own systems.

How we rate it

3.9 / 5

Our rating

From using the tool ourselves. The average of the five scores.

Ease of use
4.0

How quickly someone non-technical gets value from it.

Features
4.5

How completely it covers its own job, and how well the pieces fit together.

Output quality
3.5

How good the results are before you fix them.

Value for money
3.5

What you get for the price, including the free plan.

Speed & reliability
4.0

How fast it is and how often it falls over.

Copyleaks pricing

  • Free

    $0

    Quick one-off checks.

    • AI scans of up to 25,000 characters on the website
    • A few free credits with an account
  • Our pick

    Personal

    $16.99/mo, or $13.99/mo billed yearly

    Individuals checking work regularly.

    • 100 credits a month, about 25,000 words
    • AI and plagiarism detection
    • Browser extensions and Google Docs add-on
    • MCP access from Claude

  • Pro

    $99.99/mo, or $74.99/mo billed yearly

    Teams and agencies.

    • 1,000 credits a month, about 250,000 words
    • 25 user seats
    • Whole-website scans
    • Translated plagiarism detection
    • Analytics dashboard

  • Enterprise and Education

    Custom

    Companies and schools at scale.

    • API integration
    • LMS integrations
    • Private cloud or on-premises hosting
    • Dedicated support

Which plan should you pick?

Try the free checker first. Personal covers about 100 pages a month, which suits most individuals. Only move to Pro if a team needs seats or you want website scans. One credit covers 250 words or one image.

Prices in USD unless noted, checked 3 November 2026. Vendors change plans often, so confirm on their site before you buy.

Best use cases

Ways Copyleaks can slot into your week.

  1. 1

    Check content from overseas writers

    Scan articles in Spanish, German or Japanese for AI and plagiarism in one pass.

  2. 2

    Audit your website

    Upload your sitemap to find copied or AI-written pages before they hurt you in Google.

  3. 3

    Check from inside Claude

    Use the MCP connection to scan a draft without leaving your chat.

  4. 4

    Verify images

    Check whether a photo sent to you was made with AI.

How it fits your tech stack

It sits between writing and publishing, alongside Google Docs through the add-on. Connect it to Claude with MCP, or to your school or company systems through the API.

Connects to

Pros and cons

Pros

  • AI and plagiarism checks in one report
  • Best multilingual coverage of the major detectors
  • Catches plagiarism translated from another language
  • MCP access lets you scan from Claude
  • Checks images as well as text

Cons

  • Like all detectors, it can flag human writing
  • Personal plan's word allowance is small
  • Big jump in price from Personal to Pro
  • Switching plans wipes unused credits, and refunds are strict
  • Overlaps almost completely with Originality.ai

Copyleaks alternatives

The closest alternatives to Copyleaks in the library, best rated first.

Why it made the list

It's one of the most established AI and plagiarism checkers, with the strongest multilingual coverage of the big names.

Copyleaks FAQ

How much does Copyleaks cost?

There's a free plan, and paid plans start at $0. Prices checked 3 November 2026 against Copyleaks's pricing page.

Is Copyleaks free?

Yes, Copyleaks has a free option. Try the free checker first. Personal covers about 100 pages a month, which suits most individuals. Only move to Pro if a team needs seats or you want website scans. One credit covers 250 words or one image.

What is Copyleaks best for?

Copyleaks is best for AI and plagiarism checks in one report, checking content in languages other than English and scanning a whole website for copied pages. Schools, publishers and businesses that need AI and plagiarism checks together, especially across several languages.

What are the best Copyleaks alternatives?

The closest alternatives are Google Translate, Grammarly, Hemingway Editor and DeepL. Google Translate is best for quick translations of emails and messages.

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