Full policy: https://mangasumi.com/privacy

Sumi collects only what is needed to translate manga images, keep a reader's purchases from being charged twice, and show account and quota state. Everything is sent to mangasumi.com and nowhere else. There is no analytics endpoint, no third-party host, and no remote code.

Website content / image data: When the reader requests a translation — on demand, or automatically on a host they explicitly enabled — Sumi sends that manga image as image_b64 to https://mangasumi.com/api/web/translate-page together with page_id and target_lang, and renders the returned text back into the image. Sumi also stores the translated image locally in IndexedDB, and stores the ORIGINAL image bytes alongside it whenever the page cannot be relied on to serve them again (a blob: URL a virtualizing reader revokes, or a signed URL that expires). This local store is what lets "show original" work after a reload and stops the reader paying a second time for a page they already translated. It is bounded and evicts least-recently-used entries.

Authentication information: When the reader is signed in on mangasumi.com, a content script running on that site (first-party) asks the site to mint a bearer token for the extension. Sumi stores that token in chrome.storage.local and sends it as an Authorization header to /api/web/translate-page and /api/web/me. The token is renewed on a mangasumi.com visit and is cleared as soon as the server refuses it. It exists because Safari never lets an extension see the site's cookie, so a single header-based mechanism serves both browsers.

Personally identifiable information: /api/web/me returns the signed-in account's email, which the popup shows and which Sumi stores next to the token so it can detect that the stored token belongs to a different account than the one now signed in — the check that stops one reader's pages being billed to another.

Web history: Sumi records hostnames locally for the sites where the reader enabled auto-translate or hid the on-page control. It transmits a hostname in exactly one case: the reader presses "Report this site" in the empty state, which POSTs {host, version, platform} to /api/web/site-report. Hostname only, never a path or full URL, never automatically, and at most once per host per browser session. The reader is told what it sends before they press it.

User activity: A random anonymous id (not tied to a person) identifies the install to the free-tier daily quota, and per-tab random page ids make billing idempotent so a retry is never charged twice.

Not collected: Sumi does not collect full URLs or paths, page text or HTML, screenshots of anything other than the manga image being translated, location, passwords, payment card details, personal communications, health data, or anything at all from sites the reader has not interacted with or enabled for auto-translate.