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LanguageTool vs Grammarly

Self-host swap-in for Grammarly. · Self-host Grammarly · LanguageTool on os-alt

LanguageTool is one of the open-source self-host replacements for Grammarly — license LGPL-2.1, 10min — single Java process, optional docker-compose to stand up, and $5-10 vps; the larger n-gram dataset wants ~16gb disk + a few gb ram if you enable it. Compare against Grammarly's Free for basics; $12-15/user/mo for Premium; Business adds team analytics below.

LanguageToolopen-sourceGrammarlypaid SaaS
CategoryWriting assistant / grammar + style checkerWriting assistant / grammar + style checker
License / pricingLGPL-2.1Free for basics; $12-15/user/mo for Premium; Business adds team analytics
Starting price$0 self-host$12/user/mo
GitHublanguagetool-org/languagetool ★ 14.5k · last commit todayaliveclosed source
Setup time10min — single Java process, optional docker-composeSaaS — sign up + bill
Monthly cost$5-10 VPS; the larger n-gram dataset wants ~16GB disk + a few GB RAM if you enable it.from $12/user/mo (Free for basics; $12-15/user/mo for Premium; Business adds team analytics)

Switching from Grammarly to LanguageTool

Run `docker run -p 8010:8010 erikvl87/languagetool`. Browser extension (LanguageTool's official one) lets you point at your server URL — replaces the Grammarly extension. For Word / Google Docs, LanguageTool ships add-ons that also accept a custom server URL. IDE: the LanguageTool LSP server works inside VSCode / IntelliJ via community plugins.

Good fit for
Anyone whose Grammarly use is mostly grammar + style + multilingual checking — LanguageTool covers 30+ languages.
Weak at
Tone, rewrite, and the AI 'make it sound more confident' features are not in the free OSS server.
License note
Server is LGPL-2.1; the premium 'Picky' rules and the n-gram corpora are paid add-ons even on self-host.

Other open-source self-host alternatives to Grammarly

  • Apache-2.05min — Rust binary, also runs as a VSCode extension and a browser extension$0 — Harper runs locally (LSP) or in-browser (WASM) by default; no server required for personal use.
  • MIT10min — single Go binary + a styles directory$0 — local binary; CI cost only if you run it in pipelines.

In a terminal? npx os-alt grammarly prints Grammarly's self-host options — how the CLI works →

FAQ

Is LanguageTool a free alternative to Grammarly?

Yes — LanguageTool is open source under LGPL-2.1. Self-host cost: $5-10 VPS; the larger n-gram dataset wants ~16GB disk + a few GB RAM if you enable it.. Grammarly starts at $12/user/mo (Free for basics; $12-15/user/mo for Premium; Business adds team analytics).

How long does LanguageTool take to set up vs Grammarly?

Self-hosting LanguageTool: 10min — single Java process, optional docker-compose. Grammarly is a hosted SaaS — sign up and you're in.

What is LanguageTool good at, and what is it weak at?

Good fit for: Anyone whose Grammarly use is mostly grammar + style + multilingual checking — LanguageTool covers 30+ languages.. Weak at: Tone, rewrite, and the AI 'make it sound more confident' features are not in the free OSS server..