# languagetool-org/languagetool

Style and Grammar Checker for 25+ Languages

Repository: https://github.com/languagetool-org/languagetool
Canonical: https://ross.abutalabs.com/products/languagetool
Homepage: https://languagetool.org
Language: Java
License: LGPL-2.1
License Family: copyleft
Topics: grammar, natural-language, natural-language-processing, style-checker, proofreading, spellcheck
Last push: 2026-08-26T19:10:19+00:00

## Health v2 (maintenance only)
Score: 77/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 35, longevity 100
- inputs: {"age_days": 4773, "days_push": 7, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 14875, forks 1565 (observed 2026-08-28T04:11:08.848095+00:00)

## What it is
LanguageTool is an open-source proofreading engine that checks grammar, spelling, and style in 25+ languages. It ships as a Java library, a standalone desktop app, a self-hostable HTTP API server, and browser add-ons.

## Use cases
- check grammar and spelling in text
- self-host a grammar checking API server
- integrate proofreading into a Java application
- add grammar checking to a browser or editor
- proofread multilingual writing
- detect style and typography issues beyond spellcheck

## When to choose
- you need multilingual grammar and style checking with a self-hostable API
- you want an open-source proofreading core you can embed or extend with custom rules
- you need offline or privacy-respecting grammar checking

## When to avoid
- you only need basic spellcheck with no grammar rules
- you want a fully managed SaaS with AI paraphrasing and premium rules without self-hosting
- your stack cannot run a JVM service

## Facets
- artifact type: library
- maturity: stable
- function: nlp, http-server, sdk
- domain: developer-tools, apis
- platform: jvm, cross-platform, self-hosted, browser-extension
- tags: grammar-checker, spellcheck, proofreading, style-checker, multilingual, http-api, natural-language-processing, docker

## Member repositories
- languagetool-org/languagetool (main) score 77

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:08.848095+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:07:00.984838+00:00, confidence not recorded.
  - readme: https://github.com/languagetool-org/languagetool (fetched 2026-08-28T04:11:08.848095+00:00, sha a8ecdd555a6b)
  - homepage: https://languagetool.org (fetched 2026-08-29T08:05:03.212596+00:00, sha 8c47ca722727)
  - site_page: https://languagetool.org/google-docs (fetched 2026-08-29T08:05:03.224511+00:00, sha b8fc8f64d14b)
  - site_page: https://languagetool.org/about (fetched 2026-08-29T08:05:03.227474+00:00, sha 703e9dba1a9a)
  - site_page: https://languagetool.org/premium (fetched 2026-08-29T08:05:03.221906+00:00, sha ff4544c5ad1b)
- Data as of 2026-08-30T08:39:29.467469+00:00.