Hover Translator

VS Code extension that translates the word, string literal or selection under your cursor, without turning your editor into a request firehose.

Features

• Hover translation — rest the pointer on a word to see it in your language.
• Smart identifier handling — recognises snake_case, camelCase, PascalCase, kebab-case, Title Case and UPPER_SNAKE_CASE, including acronym runs such as parseURLValue, userID and API_V2.
• String literal translation — hover inside '…', "…" or `…` to translate its contents.
• Block translation — select a region and hover it, or run Translate Selected Block to replace or copy the result. Reserved words and identifiers are protected so the code still compiles; comments and strings are translated as prose.
• Offline dictionary — common programming words resolve locally with no network request at all (Vietnamese today).
• Six translation backends — DeepL, Google Cloud Translation, Azure AI Translator, LibreTranslate (self-hostable) and two keyless public endpoints, with automatic fallback.
• 11 languages — English, Vietnamese, French, German, Spanish, Italian, Portuguese, Russian, Chinese, Japanese, Korean.

Privacy: read this first

Translating means sending the hovered text to a translation service. On first run the extension asks once before it sends anything, and stays inactive until you accept.

Only the text you hover over is sent, never the whole file. Files matching hoverTranslator.excludeFilePatterns are skipped entirely; the default list covers .env, *.pem, *.key, id_rsa*, secrets.*, node_modules/** and other generated files.

For anything proprietary, configure an API key or self-host LibreTranslate.

Avoiding Too many requests

Keyless public endpoints are rate limited per IP, so the extension is built to send as few requests as possible. Layers, in order — a request only leaves the machine if it survives all of them:

If it still happens, the reliable fix is a key: Hover Translator: Set Translation API Key. DeepL's free tier allows 500k characters a month, which is far beyond what hovering consumes.

When every provider is cooling down, the status bar shows ⚠ Translate (5m); hover over it for a full breakdown, or run Hover Translator: Show Status.

Usage

1. Hover a word, identifier or string literal.
2. Select a region and hover it to translate the whole block.
3. Run Hover Translator: Translate Selected Block to replace or copy the result. When the selection is a single identifier, the replacement is folded back into the original casing (user_name → ten_nguoi_dung) so the code stays valid.
4. Click the status bar to toggle the extension or change the target language.

Commands

Settings

Basics

Provider

Rate limiting and performance

Example: fully local setup

{
  "hoverTranslator.provider": "libretranslate",
  "hoverTranslator.libreTranslateUrl": "http://localhost:5000/translate",
  "hoverTranslator.targetLanguage": "Vietnamese",
  // A local server has no quota, so the throttle can be relaxed.
  "hoverTranslator.maxRequestsPerMinute": 120,
  "hoverTranslator.minRequestDelay": 0
}

docker run -p 5000:5000 libretranslate/libretranslate --load-only en,vi

Caching

Translations are cached on disk in the extension's global storage and survive restarts. Entries expire cacheTtlDays days after they were fetched (reading one does not extend its life), and the least recently used entries are evicted once cacheLimit is reached. The file is written atomically, so an interrupted write cannot corrupt it.

Troubleshooting

Development

npm install
npm run watch        # esbuild in watch mode
npm run lint
npm run check-types
npm test             # node:test unit tests, no network required
npm run bundle:prod
npm run package      # requires Node >= 20 (see DEPLOY.md)

License

MIT