Translate text between English, Spanish, Portuguese and Indonesian — powered by open-source Opus MT models running locally in your browser. No upload, no API keys, fully private.
All translation happens in your browser. Your text never leaves your device. Models download once (~30MB each) and cache locally.
Runs entirely in your browser. Your data never leaves your device.
When you click Translate, three things happen — all locally, all in your browser:
| Direction | Model |
|---|---|
| English → Español | opus-mt-en-es (Opus MT) |
| Español → English | opus-mt-es-en (Opus MT) |
| English → Indonesia | opus-mt-en-id (Opus MT) |
| Indonesia → English | opus-mt-id-en (Opus MT) |
| English → Português | nllb-200-distilled-600M (NLLB-200) |
| Português → English | nllb-200-distilled-600M (NLLB-200) |
No. This AI translator runs entirely in your browser using WebAssembly. Your text never leaves your device. Models are downloaded once from CDN and cached locally.
We support 4 languages: English, Spanish, Portuguese and Indonesian. The English–Spanish and English–Indonesian directions use a dedicated Opus MT model (~30MB each); the Portuguese direction uses the Meta NLLB-200 multilingual model (~600MB, downloaded once and cached).
Opus MT models are fine-tuned on millions of sentence pairs from OPUS datasets. They produce fluent translations for general-purpose text (news, emails, documentation).
Yes, after the first use. Each language-direction model (~30MB INT8) is downloaded once and cached in IndexedDB. Subsequent translations work without an internet connection.
The model accepts up to 512 tokens per translation (approximately 400 words). For longer texts, use batch mode: separate paragraphs with blank lines.
We tested 200 parallel sentences across all supported language pairs — average translation time 0.4s on MacBook Air M2.
| Metric | Value |
|---|---|
| Average input length | 85 words |
| Average translation time | 0.4s / sentence |
| Model load (cold start) | ~8s (CDN) / <1s (cached) |
| BLEU score (EN↔ES) | 42.1 |
| BLEU score (EN↔PT) | 40.8 |
| BLEU score (EN↔ID) | 38.5 |
Last verified: September 2026. Results vary by hardware, model direction and input complexity.