API Documentation

Getting Started

Compare text, documents, images, and spreadsheets programmatically with the Diffchecker API.

Base URLhttps://api.diffchecker.com/public
OpenAPI Spec

The Diffchecker API provides HTTP endpoints for comparing text, PDF documents, images, and Excel spreadsheets. Compute text diffs, document comparisons, image diffs, and spreadsheet diffs, all with varying output types.

1

Authentication

There are two ways of interacting with the Diffchecker API:

  • Email: Just pass your email as a query string parameter. This method does not require you to have a Diffchecker account and will allow you to make as many diffs as free tier limits allow.
  • API Key: Every paid subscriber gets their own API key, which needs to be passed as the request's X-Api-Key header. This will allow you to make as many diffs as your paid plan allows.

    • When both are provided, email gets ignored in favor of the API key. The examples in these docs assume you are authenticating via email.

    2

    Rate Limiting

    API requests are rate-limited based on your authentication method. Free tier (email) users have lower limits than paid subscribers using an API key. If you exceed the rate limit, the API will return a `429 Too Many Requests` response.

    3

    Resources

    You may find the following resources helpful when dealing with PDF, Image, or Excel diffs:

  • Data URLs (MDN)
  • FormData (MDN)