Grammarly alternatives: 7 open-source picks
Grammarly costs $30/mo — $360 a year. These 7 alternatives replace it for $0, led by Harper, LanguageTool and Writing Tools. All 7 are open source. License, stars and last commit checked by hand on 2026-08-29. No trials, no crippled tiers.
A fast English grammar checker that stays on your device and mostly keeps its opinions to itself.
Grammar, style and spell checker for 30+ languages; run the server locally and keep your prose private.
licenseLGPL-2.1
runsyour server
setupnot verified by us yet — check the repo README
facts verified 2026-08-29
Select text anywhere, hit a hotkey, and fix, rewrite, summarize, or obey a custom instruction without opening another tab.
licenseGPL-3.0
runson your machine
installDownload the native or portable app, configure a provider or local model, then use the global hotkey
enginesGemini, OpenAI-compatible APIs, Ollama, llama.cpp, KoboldCPP, TabbyAPI and vLLM
dataAPI keys and settings stay locally; selected text goes to the chosen provider or local model, and transient history is cleared when the app closes
the catch vs GrammarlyIt is a manual select-text-and-hotkey workflow rather than Grammarly's continuous inline underlines and suggestions across supported apps.
setupA model API key or a separately running local model is required; some operating systems may warn about an unsigned or unrecognized binary
facts verified 2026-08-10
A LibreOffice extension with long-document checks, style statistics, profiles, and local AI; installing Java is the cover charge.
licenseLGPL-2.1
runson your machine
installInstall Java 17 or newer, LibreOffice 24.2 or newer and the WritingTool extension
enginesLanguageTool plus optional OpenAI-compatible services, especially a local LocalAI server
dataDocuments remain normal LibreOffice files; checking is local unless a remote LanguageTool or AI endpoint is configured
the catch vs GrammarlyIt is centered on LibreOffice rather than working continuously across browsers, email and arbitrary desktop apps like Grammarly.
setupJava and LibreOffice are mandatory, and optional AI needs a separately configured service
facts verified 2026-08-10
One-command local runner for Llama, Qwen, DeepSeek, Gemma and other open models with an API
licenseMIT
runsyour server
setupnot verified by us yet — check the repo README
facts verified 2026-08-29
Polished multi-model AI chat UI with plugins, knowledge base, and one-click deploy.
licenseApache-2.0
runsyour server
setupnot verified by us yet — check the repo README
facts verified 2026-08-29
One chat UI for every provider — OpenAI, Anthropic, Google, local models — with agents, search, and per-user keys.
licenseMIT
runsyour server
setupnot verified by us yet — check the repo README
facts verified 2026-08-29
What each one is, in full: LanguageTool · Ollama · Lobe Chat
last updated 2026-08-29 · no votes, no pay-to-list · just what's real
the usual suspects · recommended everywhere, rejected here
LanguageTool FreeThe engine is open source, but the browser extension went Premium-only in 2026; the free web checker no longer replaces across-app use.
how to choose a Grammarly alternative
Easiest to get running
Harper — a one-click install, no server to maintain.
Most proven
Ollama, with 178,000 GitHub stars — the largest community of the 7, which usually means more answers when something breaks.
Runs on your own machine, no server
Writing Tools — nothing to host, your data stays on your disk.
Works on your phone
Harper has a mobile app.
what you give up by leaving Grammarly
- inline suggestions everywhere
- document/email integrations
- tone/brand controls
- enterprise admin
- polished false-positive handling
None of the picks above covers all of it. The full verdict says which gaps matter.
Grammarly alternatives at a glance
| tool | license | running it | platforms | stars | active |
|---|---|---|---|---|---|
| Harper | open source | one-click install | macos, android, browser-extension | 14,200 | 2026-08 |
| LanguageTool | LGPL-2.1 | docker to self-host | self-hosted, web | 13,000 | 2026-08 |
| Writing Tools | GPL-3.0 | one-click install | macos, windows | 2,400 | 2026-05 |
| WritingTool | LGPL-2.1 | one-click install | macos, windows, linux | 65 | 2026-07 |
| Ollama | MIT | one-click install | self-hosted, web | 178,000 | 2026-08 |
| Lobe Chat | Apache-2.0 | one-click install | self-hosted, web | 65,000 | 2026-08 |
| LibreChat | MIT | one-click install | self-hosted, web | 28,000 | 2026-08 |
why people still pay for Grammarly
They pay because suggestions appear inside the apps where writing actually happens. If none of that applies to you, any pick above saves $360 a year.
questions about switching from Grammarly
Is there an open-source alternative to Grammarly?
Yes: Harper, LanguageTool, Writing Tools and 4 more. Every tool on this page is open source: no trials, no crippled tiers.
Can open source really replace Grammarly?
Our verdict is YES. Ollama (178k stars), Lobe Chat (65k stars), LibreChat (28k stars) are mature open-source replacements for Grammarly — self-host in one command and stop paying $30/mo. The full verdict, and what you give up by switching, is at caniopensourceit.online/grammarly.
What is the easiest open-source Grammarly alternative to set up?
Harper — a one-click install, no server to maintain.
What is the most popular open-source Grammarly alternative?
By GitHub stars, Ollama (178,000). Lobe Chat is next with 65,000.
