Self-hosted LanguageTool private instance is an offline alternative to Grammarly

Setting up LanguageTool is easy. If you have DNS ad blocking enabled then you will want to disable abTesting as described in this post.

docker-compose.yml

services:

  languagetool:

    image: silviof/docker-languagetool:latest

    restart: unless-stopped

    command: java -cp languagetool-server.jar org.languagetool.server.HTTPServer --port 8010 --public --allow-origin '*' --config /etc/http_server.cfg

    ports:

      - 127.0.0.1:8010:8010

    volumes:

      - ./ngrams:/ngrams

      - ./http_server.cfg:/etc/http_server.cfg

Download ngrams

These weigh about 8.3GB

mkdir ngrams

wget https://languagetool.org/download/ngram-data/ngrams-en-20150817.zip

(cd ngrams && unzip ../ngrams-en-20150817.zip)

rm -f ngrams-en-20150817.zip

Disable AB Testing

To prevent outgoing network requests to fetch said tests:

cat <<EOF > http_server.cfg

languageModel=/ngrams

abTest=null

abTestClients=null

EOF

Start Server

docker compose up -d

Install Browser Extension

• From Chrome Web Store
• From Mozilla

Configure Browser Extension

In advanced config set API server to http://127.0.0.1:8010/v2