Lingo.dev v1.0
LLMs can translate well - wrap an API call and most text comes out fine.
But a model update quietly degrades output for a locale nobody on the team understands. Product terms - feature names, UI labels - come back translated differently each time. LLM output is non-deterministic, with no memory between calls. Sounding professional in German means something different than in Japanese - and suddenly there's a per-locale prompt system to maintain, one for every language you ship.
Each looks like a quick fix. Stitch them together, and you're maintaining custom localization infrastructure - tech debt that scales with every locale you add.
Lingo.dev v1.0#
To end this maintenance cycle, we took everything we learned from translating 100M+ words for our customers and built Lingo.dev v1.0 - a localization engineering platform where teams create stateful localization engines and call them from backend code, CLI, or CI/CD pipelines for continuous localization.
A localization engine is a stateful translation API. Configure once, call everywhere:
- Models - pick from the full OpenRouter catalog, with fallback chains for reliability
- Brand voice - define linguistic rules and tone per locale
- Instructions - set per-locale translation rules for specific patterns
- Glossary - lock down product terminology so "Workspace" stays "Workspace" in every language, every build
What this means#
If you're already using Lingo.dev - the CLI, CI/CD, and MCP tools keep working as before. v1.0 adds engine configuration: model selection, fallback chains, brand voice, glossaries. All per locale. All from the dashboard. Zero migration.
If you're new to Lingo.dev - sign up and get a pre-configured localization engine, tuned for production. First translated build in 4 minutes with the CLI, or integrate via the API. Set it up once, and forget about localization.
Model freedom#
Closed-model translation APIs vendor-lock glossary, style rules, and terminology. A model regression means a support ticket. A better model from another provider? Out of reach.
Lingo.dev separates localization engineering from the model. Any model from the OpenRouter catalog works. The enrichment layer adds glossary, brand voice, and instructions to every request - producing localization tokens that steer any model toward consistent output.
Pricing is per million localization tokens, plus passthrough model costs at zero markup. Details on the pricing page.
We found that a well-built glossary reduces how much intelligence the model needs. As glossaries mature, Lingo.dev flags when a cheaper model would match the same quality.
AI Reviewers#
AI Reviewers are automated quality checks that run immediately after each translation. Define criteria in natural language - "Are all HTML tags preserved?" or "Rate naturalness for a native speaker." An independent LLM evaluates the output. If GPT-4o translates, Claude Sonnet scores - eliminating grading bias.
Cross-model evaluation catches what self-assessment misses: hallucinated terms, shifted register, broken placeholders. Sampling is configurable - 100% when precision matters, 10% in high-volume pipelines.
Playground#
Test engine configurations in the playground before they go live. Try a string, compare across locales, push to production when ready.
Reports#
Every translation request is logged: model used, tokens consumed, fallback status, applied glossary items and instructions. v1.0 ships with reports for word generations, token consumption, top locales, glossary coverage, and change rates via GitHub integration.
Who this is for#
Lingo.dev v1.0 is for teams that need localization to behave like infrastructure - stateful, configurable, API-driven. Teams like Cal.com and Solana already run their localization through Lingo.dev's open-source CLI, CI/CD, and MCP server, maintained by a 4,000-member developer community. Teams that prefer coordinating translators through review rounds may find traditional translation management platforms a better fit.
What's next#
Bring your own API keys - connect existing OpenAI, Anthropic, or OpenRouter keys to consolidate billing. Pay only for localization tokens.
Batch API - process thousands of keys in a single request for CI/CD pipelines and large-scale migrations.
Create a free developer account to get started.