Privacy Policy

Last updated: 2026-07-16

Interlinear is a Chrome extension that overlays a translation beneath the paragraph you're currently reading. This page explains what data it processes and where it goes. It doesn't require an account, a login, or any signup to use.

What text gets processed, and where it goes

Interlinear reads the text of the article paragraph you're currently viewing (or the text you select) so it can translate or explain it. What happens to that text depends entirely on which translation provider ends up handling the request:

• Chrome's built-in Translator/Prompt API (used by default, when available) — runs entirely on your device. The text never leaves your computer or goes to any server, Interlinear's or anyone else's.
• LibreTranslate (optional, off by default) — only used if you type an endpoint into the popup settings. If you do, the paragraph text is sent to that specific server for translation. If you're self-hosting your own instance, that's a server you control; if you point it at someone else's instance, their privacy policy applies to that request. Interlinear asks Chrome for permission to contact that one server the moment you save the endpoint — it doesn't have standing access to any other site for this purpose.
• DeepL (optional, off by default) — only used if you paste a DeepL API key into the popup settings. If you do, the paragraph text is sent to DeepL's API to be translated, subject to DeepL's own privacy policy.

Chrome's translation/explanation APIs and the two optional fallbacks above are the only places paragraph text is ever sent. Interlinear itself has no server and doesn't collect, log, or transmit anything you read.

What's stored, and where

• Translations are cached on your device (in-memory for the current tab session, and in IndexedDB for up to 30 days) so the same passage doesn't get re-translated every time. This cache never leaves your device.
• Settings (enabled/disabled, languages, display mode, font size, and the optional LibreTranslate/DeepL configuration) are stored via chrome.storage.local — local to your device and browser profile. Interlinear never asks Chrome to sync any of this across your devices.

What Interlinear does not do

• No analytics, telemetry, or usage tracking of any kind.
• No third-party scripts, trackers, or ads.
• No account, login, or signup.
• No data sold or shared with advertisers.

Permissions, and why

• storage — to save your settings and translation cache locally, as described above.
• Content script access to http://*/* and https://*/* — this is what lets the translation overlay appear automatically while you read, without clicking anything first. Interlinear only actually does anything on pages it detects as an article (via a readability check); it stays completely inert on everything else (webmail, dashboards, video sites, etc.).
• host_permissions for api-free.deepl.com/api.deepl.com — fixed DeepL API domains, needed only when you've configured a DeepL key.
• optional_host_permissions for arbitrary hosts — requested at the moment (and only for the specific server) you configure a LibreTranslate endpoint. Not granted otherwise.

Changes to this policy

If this policy changes, the updated version will be posted at this same location with a new "last updated" date.

Contact

Questions about this policy or the extension can be filed as an issue on the project's repository.