Comparison

Polylens vs Lingo.dev

Lingo.dev writes translations. Polylens checks that whatever shipped is healthy.

Lingo.dev is an AI localization toolkit: a compiler and engine that produce translations for your app, aiming to remove translation keys and JSON juggling altogether. It answers the question "how do I get this translated?"

Polylens answers a different question: "are the locale files we ship right now broken?" It is the independent check that catches missing keys, dropped placeholders, untranslated copy, and stale strings, whoever produced them: humans, agencies, or an AI engine.

Side by side

Polylens

Lingo.dev

Primary job

✓ Translation quality gate in CI

AI-generated translations

Produces translations

✓ No, by design

Yes, that is the product

Verifies shipped files

✓ Yes, 13 issue classes

Validates what it generates

Vendor-independent check

✓ Yes, works with any source of strings

Coupled to its own pipeline

Health score and drift trend

✓ Yes

CI gate that fails the build

✓ Yes, HTTP 422 on regression

CI integration for translation runs

Works without changing your build

✓ Yes, reads plain JSON and YAML

Compiler or pipeline integration

Price

✓ Free tier, Team $19/mo

Free OSS core, paid engine usage

When Lingo.dev is the right call

·You want AI to produce your translations and minimize i18n plumbing.
·You are starting fresh and can adopt its compiler-driven workflow.

When Polylens is the right call

✓You need an independent gate on translation quality, whatever produces the strings.
✓Your locale files come from mixed sources: translators, PRs, machine translation.
✓You want drift caught in CI without changing how you build or translate.

Generator and gatekeeper. If you adopt AI translation, an independent health check matters more, not less. Run Polylens on the output and let CI prove it is safe to ship.

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