Is online translation safe for confidential documents?
For public text, yes. For confidential text, only as safe as the company that receives it: an online translator works by sending your words to its servers, where they are processed and may be logged, kept or reviewed under its policy. If the text must not leave your hands, translate it on your own device, so it isn't sent anywhere.
Updated:
What happens to the text you paste into a translator
When you paste a paragraph into an online translator or upload a file, it travels over the internet to the provider's servers, a translation model runs there, and the result comes back. What happens to it after that depends on the service, its settings and its policy, which can change:
- Logs and storage. Requests may be kept for a time, for debugging, abuse checks or legal reasons.
- Improving the service. Free services in particular may use what you submit to train or evaluate their models.
- Human review. Some services let staff or contractors review samples of what was translated.
- Your account and your browser. History may be saved to your account, and browser extensions may see the page too.
None of this is unusual or sinister: it is how cloud services work. But even a good policy is only a promise about text that has already left.
When it matters
It matters when the text is not yours to share, or would hurt you if it leaked:
- contracts, NDAs, court papers and anything covered by professional confidentiality or privilege;
- medical records, test results and letters from a doctor;
- bank statements, tax documents, passports and ID numbers;
- unpublished work, source code, business plans and internal email;
- private messages from other people.
Many companies forbid pasting such text into public online tools for exactly this reason. Before translating a client's or an employer's document, check what your rules allow.
How to check whether a translator sends your text
- Switch off Wi-Fi and try to translate. If it still works, the translation happens on your device.
- If it only works online, it is sending the text somewhere. Read its privacy policy for what happens to it.
- In a browser, open the developer tools, choose the Network tab and watch the requests while you type.
Translate confidential text on your own device
Kalila translates on the device, so there is no server that receives your text:
- On a Mac: select text in any app and press ⌃⌥T, or type it into Kalila in the menu bar. Kalila for Mac uses Apple's on-device translation and only languages downloaded to your Mac. It is free and needs no account.
- In any browser: paste the text into kalila.app/translate. The translation engine runs inside the tab, and the page lists every request it makes, live, so you can see that none of them carries your text.
Version 0.2.3 · macOS 26.4 or later · Apple Silicon
The trade-off
Online translators run large models on powerful servers and can translate better on some language pairs and on long, nuanced text. They also handle whole documents and photos, which Kalila doesn't. If the text is public, use whatever translates it best; if it is confidential, keep it on your device.
Questions
Do online translators keep what I translate?
It depends on the service and its settings. Many keep requests for some time, and some use them to improve their systems. The policy tells you; a translator that runs on your device has nothing to keep.
Is a paid plan safer than a free one?
Often, yes: paid and business plans tend to have stricter terms, such as not using your text for training. But the text still travels to the provider's servers to be translated.
Is it safe to translate a contract online?
If the contract is confidential, sending it to a third party may itself break the confidentiality you agreed to. Translating on your own device avoids the question: no one else receives it.
Does Kalila send my text anywhere?
No. Kalila has no account, no analytics and no server that receives your text. The internet is used only to download languages and updates — the same files for everyone.
Is offline translation good enough for important documents?
For understanding a document and working with it, usually yes. For a translation that will be signed or filed, use a professional translator, and keep the machine translation as your own working copy.
Related
- Machine translation for lawyers: keep client documents confidential
- Translating medical records without sharing them
- How to translate a PDF on a Mac without uploading it
- A private translator