LanguageTool costs $5.47/mo.
These cost $0.
4 free alternatives to LanguageTool, checked for license, recent activity and real adoption. Each one tells you the catch, so you can switch with your eyes open.
LanguageTool vs Free Alternatives Matrix
Quick side-by-side comparison · $0/mo vs $5.47/mo
| Alternative | Type | License | Where It Runs | Stars | Head-to-Head |
|---|---|---|---|---|---|
| Harper | open source | — | — | ★ 14k | LanguageTool vs Harper → |
| Writing Tools | open source | GPL-3.0 | Local | ★ 2.4k | LanguageTool vs Writing Tools → |
| WritingTool | open source | LGPL-2.1 | Local | ★ 65 | LanguageTool vs WritingTool → |
| Apple Writing Tools | free | proprietary, free | Local or hosted | ★ $0 forever | LanguageTool vs Apple Writing Tools → |
The picks
3 open source · 1 free to use · ranked by fit
- 01
Harper
open source14kaug 2026A fast English grammar checker that stays on your device and mostly keeps its opinions to itself.
Install, platforms & data +
- platforms
- desktopmobileextensionone-click install
- 02
Writing Tools
open sourceGPL-3.0Local2.4kmay 2026Select text anywhere, hit a hotkey, and fix, rewrite, summarize, or obey a custom instruction without opening another tab.
The catch vs LanguageToolIt relies on generative models for corrections, so checks are less deterministic and its multilingual grammar rules and explanations are much thinner than LanguageTool's.
Install, platforms & data +
- platforms
- desktopone-click install
- install
- Use the portable Windows ZIP or macOS DMG; Linux currently runs from source
- setup
- You must supply an API key or install a local model; macOS needs Accessibility permissions, while Linux installation and Wayland support remain rough
- engines
- Gemini, native Ollama and any OpenAI-compatible cloud or local endpoint on Windows/Linux; the macOS port also supports OpenAI, Anthropic, Mistral, OpenRouter, Gemini, MLX and Ollama
- your data
- API keys and configuration stay on the device; the app does not retain writing or logs, and selected text goes only to the chosen cloud provider unless a local model is used
- checked
- 2026-08-14
- 03
WritingTool
open sourceLGPL-2.1Local65jul 2026A LibreOffice extension with long-document checks, style statistics, profiles, and local AI; installing Java is the cover charge.
The catch vs LanguageToolIts LanguageTool-based checks are strong inside LibreOffice, but browser, email, mobile, and cross-application coverage are much weaker than LanguageTool's.
Install, platforms & data +
- platforms
- desktopone-click install
- install
- Install LibreOffice 24.2+, Java 17+, then add the downloaded .oxt LibreOffice extension
- setup
- Java 17 and a recent LibreOffice are mandatory, and users must manually install and approve the extension
- engines
- LanguageTool rules locally; optional AI rewriting through an OpenAI-compatible API, with local endpoints such as LocalAI specifically supported
- your data
- Checks, profiles and cached document-analysis data run on the local computer; document text is sent away only when a remote LanguageTool or configured AI endpoint is used
- checked
- 2026-08-14
- 04
Apple Writing Tools
freeproprietary, freeLocal or hostedProofread, rewrite, shorten, or change tone almost anywhere, assuming your Apple hardware made the guest list.
The catch vs LanguageToolIt is convenient on supported Apple hardware, but it covers fewer languages and gives less rule-based grammar explanation and customization than LanguageTool.
Install, platforms & data +
- platforms
- desktopmobileone-click install
- install
- Built into current macOS, iOS and iPadOS; enable Apple Intelligence and let the required models download
- setup
- Requires Apple Intelligence-compatible Apple hardware, a supported language/region and several gigabytes of downloaded models
- engines
- Apple on-device foundation models and, for harder requests, Apple Private Cloud Compute; optional ChatGPT is used for Compose
- your data
- Edits are applied to text in the host app rather than kept in a separate Writing Tools library; on-device requests stay local, Private Cloud Compute says request data is not stored, and optional ChatGPT receives the selected content
- checked
- 2026-08-14
Frequently Asked Questions
Direct answers · LanguageTool open-source replacements
What is the best free alternative to LanguageTool?+
The top free alternative to LanguageTool is Harper (open source). A fast English grammar checker that stays on your device and mostly keeps its opinions to itself. Other popular LanguageTool replacements include Writing Tools, WritingTool, Apple Writing Tools.
Can I self-host a free replacement for LanguageTool?+
Yes. Of the 4 free alternatives to LanguageTool, 1 can be self-hosted on your own server or local machine: Apple Writing Tools (proprietary, free).
How much does switching from LanguageTool to a free alternative save?+
LanguageTool starts at $5.47/month per seat ($66/year). Switching a 5-person team to a free alternative like Harper saves $328 per year in software subscription fees.
Should I vibe-code or build my own LanguageTool clone from scratch?+
Our build verdict for LanguageTool is YES (the core loop fits in a weekend). Because the core engine is open source, a technical user can run the grammar checker locally or self-host the server for many use cases.
