What is Sakana Translate?
Sakana Translate is a free translation tool from Tokyo-based Sakana AI, launched on 6 July 2026 as part of Sakana Chat; translate.sakana.ai now redirects to chat.sakana.ai/translate. It translates between Japanese, English and Chinese in both directions, with the aim of carrying over tone, politeness and context rather than just the words.
It has three modes. Translate streams the result as it is written and keeps a history. Proofread rewrites a draft to sound natural and highlights every change. Ask lets you question a result: what a nuance means, another way to say it, or why a word was chosen. Since 21 August it runs on the newer generation of Sakana's Namazu model.
It is free; registering an account opens all three modes. Sakana's announcement puts the limit at about 5,000 Japanese characters per request, and the signed-out page shows a 2,000-character box. File translation, glossaries, an API and business features such as SSO are listed as plans, not products.
Is Sakana Translate worth it?
Translating Japanese is rarely about vocabulary. The hard part is register: whether a sentence should sound like a note to a colleague or a letter to a client, and how to render a cultural idea such as Omiyamairi, a baby's first shrine visit, without a clumsy footnote.
Sakana Translate is aimed squarely at that. It works between Japanese, English and Chinese, and runs on Sakana's Japanese-tuned Namazu model; Sakana's own review on real Japanese texts found it handled honorifics, place names and cultural concepts well. The Proofread mode is the more useful half for many readers: paste your own Japanese or English draft and it rewrites it for tone and politeness, highlighting each change so you can learn from it. Ask mode lets you query a single phrase, which a plain translator cannot do.
Sakana's evidence is its own. On an in-house set of 160 Japanese-to-English tasks, judged by its own TransEvalnia method, it says its output won more than half of head-to-head comparisons against every system tested. The announcement does not name those systems or give exact win rates, so treat the claim as a direction rather than a ranking.
The catch: it is narrow. Three languages, pasted text up to about 5,000 characters, no document upload, no glossary for your company's terms and no API. Because it lives inside Sakana Chat, it inherits that service's terms: inputs may train Sakana's models unless you opt out, personal information is banned, and the FAQ says the service works only from Japan.
Our take: for a single email or a page of slides between Japanese and English, it is worth a tab beside your usual translator, mostly for Proofread and Ask. For contracts, customer data or anything with names in it, the terms make that decision for you.
Where it earns its place
A Japanese engineer writing to an overseas supplier
Turn a careful Japanese email into natural business English
Paste the email into Translate, then use Ask on any phrase that reads oddly. Free, and short enough to sit well inside the 5,000-character limit.
A foreign hire at a Tokyo company
Check that a Japanese message to a manager uses the right level of politeness
Run the draft through Proofread, which rewrites for register and highlights each change, so you can see which honorifics it fixed and why.
A marketing team localising a Chinese product page for Japan
Get a first-pass Japanese version with culturally natural wording
Translate section by section, since there is no file upload. Have a native speaker sign off, as Sakana's quality figures are self-reported.
Before you commit
- Setup
- Open chat.sakana.ai/translate (translate.sakana.ai redirects there), paste text and choose a mode; register a free account to get all three modes.
- Integrations
- None yet. File translation for PDFs and Office documents, glossary integration, industry-specific models, an API, SSO, audit logs and on-premises deployment are listed as future plans.
- Data and privacy
- Translate sits inside Sakana Chat, whose FAQ says inputs may be used to train Sakana's models, with an opt-out under Privacy in settings. Data is stored on Google Cloud in Japan, and the terms bar entering personal information. Which AI tools train on your data?
- Limits
- Japanese, English and Chinese only; about 5,000 Japanese characters per request according to the announcement, with a 2,000-character box on the signed-out page; pasted text only.
What's good
- Free
- Proofread mode highlights each change to tone and politeness
- Ask mode explains nuance and word choice
- Handles honorifics and Japanese cultural terms well, by Sakana's account
- Japanese, English and Chinese in both directions
What's not
- Only three languages
- Pasted text only, about 5,000 characters per request
- No file translation, glossary or API yet
- Quality claims rest on Sakana's own test set
- Trains on inputs unless you opt out; personal information banned
Best for
People in Japan who write in Japanese and English for work and want a free second opinion on tone and politeness, not a document translation pipeline.
Sakana Translate alternatives
Sakana Translate: common questions
- Is Sakana Translate worth it?
- A free translator that gets Japanese politeness right more often than a generic tool and can explain why, but it handles three languages, pasted text only, and nothing you would not post publicly. We rate it 3.5 out of 5.
- How much does Sakana Translate cost?
- Free; a free account opens Translate, Proofread and Ask. No paid plan or API yet.
- What are the downsides of Sakana Translate?
- Only three languages; pasted text only, about 5,000 characters per request; no file translation, glossary or API yet; quality claims rest on Sakana's own test set; trains on inputs unless you opt out; personal information banned.
- Who is Sakana Translate best for?
- People in Japan who write in Japanese and English for work and want a free second opinion on tone and politeness, not a document translation pipeline.
- Is Sakana Translate safe for company data?
- Translate sits inside Sakana Chat, whose FAQ says inputs may be used to train Sakana's models, with an opt-out under Privacy in settings. Data is stored on Google Cloud in Japan, and the terms bar entering personal information.
- What are the best Sakana Translate alternatives?
- The closest alternatives we have reviewed are Sakana Chat, ChatGPT, Google Gemini and Grammarly.
Answers checked Oct 26, 2026.