LangSync
AI-powered localization API for managing translation strings across 100+ languages.
LangSync centralises every translation string in your product, generates context-aware translations with AI, and exposes them as i18n-ready JSON over a REST API. It replaces the spreadsheet-and-Slack workflow most teams ship with – one dashboard for your source strings, glossaries to keep terminology consistent, and resumable batch jobs that auto-translate everything you haven't filled in.
What you can do with LangSync
Manage source strings
Add, edit and group translation keys in namespaces – one workspace per app, module, or client project.
Auto-translate to 100+ languages
Fill missing translations across every enabled language with one click, or stream a single string in real time.
Keep terminology consistent
Define brand names, product terms and untranslatables in a glossary the AI consults on every call.
Fetch translations from your app
Pull the latest strings via the public API with a long-lived API key – no rebuilds, no CDN flushes.
Core concepts in one minute
- Namespace – an isolated translation workspace (one per app or client). Has a default language and a set of enabled target languages.
- Term – a translation key (like
welcome.titleorbutton.submit). - Translation – the actual string for one term in one language.
- Glossary – an organization-wide dictionary that constrains how specific words must (or must not) be translated.
- Sync job – an asynchronous push of a project's strings, optionally followed by AI auto-translation across every missing language.
Pricing
LangSync bills per non-empty translated string stored – empty translations don't count, and every namespace × language combination is counted once per term. See Platform → Billing for the current rates.