Deploy and Host LanguageTool on Railway

LanguageTool is an open-source grammar, style and spell checker covering more than 30 languages. This template runs its HTTP API server (/v2/check) as a single service from a digest-pinned community image, with language detection enabled and the JVM heap sized to the container.

About Hosting LanguageTool

LanguageTool is a Java server and needs a few things handled for Railway, all done in the start command:

Heap from the container, not the host. The JVM would otherwise size itself from the host's memory. The start command reads the container memory limit and sets the maximum heap to 70% of it (capped at 6 GB).
Railway's port. The server listens on the port Railway injects, so the HTTP healthcheck on /v2/languages reaches it.
Language detection. The bundled fastText model is enabled, so language=auto works.
No state. Rules and models ship inside the image, so no volume is needed.

Why Deploy

A drop-in /v2/check endpoint for editors, browser extensions and apps
No text leaves your own infrastructure
No variables to fill in; deploy and call the API
Image pinned by digest, so a deploy never changes under you

Common Use Cases

Grammar and spell checking inside your own writing or CMS tool
Backing the LanguageTool browser extension or editor plugins with a private server
Proofreading user-submitted text in an application pipeline
Self-hosted alternative to Grammarly-style cloud checkers

Dependencies for LanguageTool Hosting

None. LanguageTool runs as one service with no database or volume.

Deployment Dependencies

LanguageTool: https://github.com/languagetool-org/languagetool
HTTP server docs: https://dev.languagetool.org/http-server
Community image: https://hub.docker.com/r/erikvl87/languagetool

Implementation Details

Check a text:

curl -d 'language=en-US' --data-urlencode 'text=This are a tset.' https:///v2/check

The API is open to anyone who knows the domain. Put it behind your own proxy or keep it on the private network if that matters. Premium-only rules and n-gram data are not included.

Why Deploy LanguageTool on Railway?

Railway is a singular platform to deploy your infrastructure stack. Railway will host your infrastructure so you don't have to deal with configuration, while allowing you to vertically and horizontally scale it.

By deploying LanguageTool on Railway, you are one step closer to supporting a complete full-stack application with minimal burden. Host your servers, databases, AI agents, and more on Railway.