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How to choose a translation engine

A translation engine is the underlying service that converts your text from one language to another. Different engines have different strengths — speed, tone, and language coverage all vary. Lokalize lets you choose, and your selection applies to bulk translate, auto-translate, and per-field AI translate.

Change your engine​

  1. Open Lokalize → Account → Settings.
  2. Choose your engine under Translation Engine.
  3. Save.

The change takes effect immediately and applies to future translations only — existing translations aren't re-translated. If you downgrade to a plan that doesn't include your current engine, Lokalize switches you back to the Default engine.

Screenshot pending

Account settings page with the Translation Engine selector

The built-in engines​

Default​

The standard engine, available on every plan including Basic. Fast, reliable neural machine translation with the broadest language coverage. Best for high-volume, straightforward content like product specs, size guides, and policy pages.

ChatGPT​

Available on Pro and higher. AI-powered translation with improved accuracy, tone awareness, and natural phrasing. Best for marketing copy, hero sections, and customer-facing content where tone matters.

You don't need an OpenAI account for this — it's included with your plan and billed through your Lokalize word balance.

Bring your own key (Business)​

On the Business plan you can connect your own provider account and use these engines with your own API key:

  • DeepL (BYOK)
  • DeepSeek (BYOK)
  • ChatGPT (BYOK)

How BYOK works:

  • Paste your provider API key in Account → Settings. Your key is stored encrypted.
  • Translations made with a BYOK engine are billed directly by your provider, not against your Lokalize word balance.
  • If your key is invalid or your provider rejects a request, the error is surfaced so you can fix it — BYOK never silently falls back to another engine.

Language fallback for LLM engines​

The Default engine supports the broadest range of languages. The AI (LLM) engines may not support every language Lokalize offers. When you translate into a language an LLM engine doesn't support, Lokalize automatically falls back to Google Translate for that specific language. Your other languages keep using your selected engine.

Glossary works with every engine​

Whichever engine you choose, your Glossary rules are respected, so brand names and preferred terms stay consistent everywhere.