LanguageTool
FreemiumUntestedOur check runs without a key, so we couldn't test this one. It doesn't mean it's down.
Checks grammar, spelling and style in 30+ languages; free public endpoint, paid API for scale.
Example request
curl -s -X POST 'https://api.languagetool.org/v2/check' --data 'text=This are a test&language=en-US'
Free tier, in plain English
The free public checker needs no key but is rate-limited per IP; it's meant for manual or low-volume use, not automated integrations.
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