This page describes the technical specifications of the Copyleaks API.

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Page Definition

A page is defined as up to 250 words. This means that every 250 words (or portion thereof) in your document counts as one page for billing purposes. How Page Counting Works:
  • 1-250 words = 1 page
  • 251-500 words = 2 pages
  • 501-750 words = 3 pages
  • etc.

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Input Limits

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Supported Plagiarism File Types

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Supported Textual File Types

All supported plagiarism file types are also supported when submitted online by URL.

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Supported Image Types (OCR)

The supported image files are pdf, docx, gif, png, bmp, jpg and jpeg . The files must contain textual content. Upload only.

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Supported Plagiarism Languages

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File Size

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Rate Limit

An account by default has a rate of 600 requests per minute, shared across all your Copyleaks API calls. Some endpoints have stricter limits, listed on Rate Limits. If you still need higher rates, feel free to contact us.

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Maintenance Periods

When our servers are under maintenance you will receive a 503 HTTP status code. Please wait a full minute and try again. For more information about the service status - Copyleaks System Status.

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Time

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Scan Expiration

Your created scans using the /v3/submit endpoints will be stored in Copyleaks servers for a specific duration of time. You can control the expiration of your scans in your submit request. Make sure you save your data before it expires:

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Frequently asked questions

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How does Copyleaks count pages for billing?

A page is defined as up to 250 words. Every 250 words (or portion thereof) counts as one page, so 1-250 words is 1 page, 251-500 words is 2 pages, and so on.

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What is the maximum file size I can submit?

It depends on the file type: 50 MB for non-textual documents (PDF, DOC, DOCX), 25 MB for images submitted to OCR, 5 MB for HTML files, and 3 MB for text and source-code files.

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What is the maximum document length?

2000 pages, which is approximately 500,000 words.

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What is the Copyleaks API rate limit?

600 requests per minute per account by default, shared across all your Copyleaks API calls. Going over it blocks requests from your IP addresses for 5 minutes. Endpoints with their own stricter limits return HTTP 429 (Too Many Requests) instead. Contact Copyleaks if you need a higher rate.

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How long are scans stored before they expire?

Scans are stored for 2880 hours (120 days) by default, which is also the maximum. You can set a shorter expiration in the submit request, so save your results before they expire.