LanguageTool

Overview

LanguageTool is a free public API in the Text Analysis category. Style and Grammar Checker for 25+ Languages.

Text-analysis APIs handle sentiment, extraction, and language processing so apps can make sense of unstructured text.

You can use this API in prototypes, side projects, and production applications — just keep the provider’s usage policy in mind.

Authentication

LanguageTool requires no authentication — you can start calling it directly, which makes it great for quick experiments and client-side demos.

HTTPS & CORS

• HTTPS: not supported — LanguageTool is served over plain HTTP only. Avoid sending sensitive data, and prefer HTTPS endpoints where possible.
• CORS: unknown — if you plan to call LanguageTool from the browser, verify CORS support in the official docs or with a quick test request.

Getting Started

1. Read the official documentation: https://languagetool.org/http-api/
2. Make a test request with curl or your favourite HTTP client.

Rate Limits & Notes

• Rate limits, quotas, and free-tier terms are defined by the provider — always check the official documentation for LanguageTool before scaling up.
• The upstream listing is community-maintained; fields like auth, HTTPS and CORS reflect the state at listing time and may change.

FAQ

Does LanguageTool require an API key?

No — LanguageTool is listed as a no-auth API, so you can call it directly.