Writing and content decision
LanguageTool
Because the official LanguageTool implementation is open-source (LGPL) and provides the grammar engine and server, a technical user can self-host the core product; keep paying only if you need the vendor's hosted premium/paraphrasing or managed team features.
Visit website↗Open-source builds that already do this
Every project below is open source and already does this job today. Fork one, self-host it, or take the parts you need — the build prompt further down assumes an empty file, and this is the shortcut past that. Licences differ; check the one on each card before you ship.
What a replacement has to do
- Self-host the open-source LanguageTool server and expose a REST endpoint that accepts text and returns grammar/style suggestions.
What it still won’t have
- Hosted Premium features and subscription management (cloud account, billing)
- Any proprietary A.I. paraphrasing models or hosted paraphraser if those are not included in the open-source repo
- Built-in cloud editor features like synced Personal Dictionary / statistics unless you implement them
- Managed uptime/SLA and automatic platform updates
What remains hard
- Brand trust
2000+ organizations trust our AI-based writing tools
First-year cost
Keep paying
Paying is—cheaper in year one.
On cash alone, building overtakes the subscription at 3 seats.
Money you would actually spend
Time you would spend
—
What you would spend
What we assumed
The verdict above measures whether you could build it. This one is only about money.
Runnable build prompt
Build a self-hosted LanguageTool service using the upstream Java code from https://github.com/languagetool-org/languagetool. Stack: OpenJDK 11+, PostgreSQL (optional for dictionaries), Nginx reverse proxy, systemd service. In scope: fetch and build the repo, run the LanguageTool HTTP server, configure TLS via Nginx, add a single-user auth mechanism (basic or OAuth), provide a /check REST endpoint that accepts text and returns JSON suggestions, mount a configurable user dictionary directory, and deploy on a single small VM (2 vCPU, 4GB RAM). Out of scope: reimplementing rule engine logic, training any proprietary paraphrasing models, multi-tenant billing. Require: robust error handling, logging, automated start/stop scripts, and at least 10 automated integration tests that validate the /check endpoint across three languages.
How we checked
How the score was reached
- Self-host verdict base92
- An open-source build was found+5
- 5 cited sources+3
- 3/3 assessment runs agreed+4
- Evidence score99
The base comes from the verdict. Everything under it is a check that either happened or did not, and each one is a fact frozen in this record rather than a judgement made at render time — so the same evidence always produces the same number.
How scoring works →Cited sources · 5
Every page the run actually retrieved.
- official productLanguageTool — official product
- official pricingLanguageTool — Premium
- official docsLanguageTool — Google Docs integration
- open sourcelanguagetool-org/languagetool
- open sourceAutomattic/harper
Integrity checks
What held up, and what did not.
