Privacy Policy

Last updated: October 11, 2026

Sumi (the app) is a manga translation reader. The app is published by the Sumi team (the publisher, contact: hello@mangasumi.com). This page explains what we collect, when, and why.

Sumi ships as an iPhone and iPad app (with the Sumi Safari extension), an Android app on Google Play, extensions for Chrome and Firefox, and the mangasumi.com website. All of them use the same Sumi account. A section that names one of them applies only to that one. The two apps have their own sections: Sumi for iPhone and iPad and Sumi for Android.

Plain-language summary

One account everywhere. A Sumi account holds your pages and your plan, and they are the same in the iPhone and iPad app, the Safari extension, the Android app, the Chrome and Firefox extensions and on mangasumi.com. You sign in with Apple, Google or a one-time email code. We keep the account's email address, its display name and its profile picture if it has one, and show them back to you so you can see which account you are signed in to.
When you need an account. On a new iPhone or iPad install, cloud translation, free pages and purchases need an account; reading your own files and offline translation do not. If you used the iPhone or iPad app before Sumi accounts existed, signing in there is optional. The Android app requires an account. On the Chrome and Firefox extensions and the website, an account is optional.
The offline tier of the iPhone and iPad app never sends your manga pages anywhere: detection, OCR and translation all happen on your device. The Android app has no offline engine.
The online tier sends what you are translating — the page image, a single speech bubble when you ask for one bubble to be translated again, the manga image you choose in an extension, or a passage of text from an e-book or a PDF — to our Cloudflare-hosted relay, which forwards it to a vision-language model (a fast Google Gemini model via OpenRouter). We do not keep the image or the text you send. We keep the text read from a page and its translation for up to 30 days, filed under a fingerprint of the image rather than under who you are, so the same page is not translated twice.
The iPhone and iPad app counts how its features are used, under a random identifier the app creates for itself — not under your name or your email address.
We do not track you across other companies' apps or websites, we do not use an advertising identifier, and we do not sell your data or share it for advertising. We do not collect your phone number.

What we collect

Your Sumi account

What	When	Why we need it	How long we keep it
Email address	When you sign in with Apple, Google or an email code. With Apple's Hide My Email, it is the relay address Apple gives us	To identify the account, send sign-in codes, and show you which account you are signed in to	Until you delete the account
Display name	The name you enter when you register, the name Google shares, or the name Apple shares the first time you use Sign in with Apple	Shown back to you in the apps and on the website	Until you delete the account
Profile picture	Shared by Google, or uploaded by you in your account settings on mangasumi.com	Shown back to you in the apps and on the website	Until you delete the account
Sign-in methods	When you sign in with Apple or Google	The identifier Apple or Google gives the account, so the same login always reaches the same account. For Apple, also an encrypted token Apple issues at sign-in, kept only so we can revoke Sign in with Apple when you delete the account	Until you delete the account; the Apple token until Apple confirms the revocation
Signed-in devices	Each time an app, an extension or a browser signs in	To keep you signed in and to sign you out everywhere. A browser session on the website also records that browser's IP address and user agent	Until you sign out, the session expires, or you delete the account
Pages, plan and purchases	When pages are added, claimed or spent, and when you buy	The account's page balance and its history, its subscription, and the store's record of each purchase (App Store, Google Play or Stripe transaction, product, amount, time), so each purchase is credited exactly once, to the right account	While the account exists. Purchase records outlive a deletion for refunds and accounting — see Delete your Sumi account and data
IP address of a signed-in translation	Each page you translate while signed in	To spot abuse of an account	Deleted after 90 days

Emails we send

We email your account only its sign-in codes and notices about the account itself. Creating an account does not put you on any mailing list: if we send product-update emails, you get them only after you choose to subscribe, and you can unsubscribe at any time.

What you translate

What	When	Why we need it	How long we keep it
The page image — a scaled-down image of the page; a single bubble when you ask for one bubble to be translated again	Each cloud translation	To transcribe and translate it	Discarded as soon as the response is returned
Text you translate — a passage of an e-book, a word you look up, or text you select in a PDF	Each text translation	To translate it	Discarded as soon as the response is returned
The text read from a page, and its translation	After a page is translated	So the same page in the same language is answered at once instead of being translated again	Up to 30 days, filed under a fingerprint of the image and the language — never under your account, your device or the site the page came from
A per-page charge key	Each translation	So re-translating the same page does not charge you twice	Briefly; the charge record itself (amount, time, identifiers — never the image) is kept for billing

Things we infer

What	Source	Why
Aggregate daily request counts per device or account	A counter in our edge storage	Abuse and runaway-bill defense. We see only the count, not the request.
RevenueCat events (purchase, renewal, refund)	RevenueCat webhook	To grant or end what was bought

Account events

Our server records three account events in PostHog under the account's id: an account being created (with the domain of its email address, such as gmail.com), a sign-in (with the method used), and a free-page claim made in the iPhone and iPad app or the Safari extension. They count sign-ups and claims; they hold no email address and nothing you read.

Things we don't collect

We do not collect your phone number, contacts, location, photo library, microphone or camera.
We do not collect the manga files you import. They stay on your device; when you translate one of their pages with the online tier, that page is sent as an image and discarded once the translation is returned.
A translation request never carries the address of the page you are reading.
We do not use an advertising identifier, do not track you across other companies' apps or websites, and never use what you read for advertising.

Website analytics

On the mangasumi.com website (separate from the app's reading experience) we use a privacy-light, cookieless PostHog setup to count page views and understand which pages and sign-up/checkout flows people use. It sets no analytics cookies, disables automatic interaction capture and session recording, and honors Do Not Track and Global Privacy Control.

Visitors who are 18 or older may separately opt in to Microsoft Clarity. Clarity creates heatmaps and a replay of website interactions from page structure, clicks, scrolling, and pointer movement; it is not a camera or a video recording. The Clarity script is not loaded until consent is granted. Inputs are masked, and account, authentication, settings, admin, and online translation areas are fully masked. You can withdraw consent at any time with Privacy choices in the footer, which also clears Clarity cookies.

Clarity code is served only by pages we operate on mangasumi.com. It cannot observe third-party manga sites opened through the Sumi iOS app or the Safari, Chrome, and Firefox extensions, and it is never used to profile what manga you read. Microsoft's privacy statement applies to its processing of consented Clarity data.

Where your data goes

When you use the online translation tier, each request is relayed through:

Cloudflare Workers (our edge function at mangasumi.com) — checks your balance or plan and forwards the image or text to the model provider.
OpenRouter (gateway).
A Google Gemini vision model (the actual translation model).

The model provider's privacy commitments apply during their handling. We do not send anything with the request that would let the model provider identify you personally — no Apple ID, no email, no name.

The offline translation tier never leaves your device. All inference runs locally.

Other services that handle data for us:

Service	What it does for Sumi
Cloudflare	Hosts the website and our API, and stores the account, page and purchase records and uploaded files
RevenueCat	Validates App Store and Google Play purchases and tells us what to grant
Apple	Sign in with Apple, App Store purchases, App Attest, notifications, and Apple Search Ads attribution
Google	Sign in with Google, Google Play purchases, and Play Integrity
Stripe	Website payments — we never see your card details
Resend	Sends sign-in codes and account emails, and product emails if you subscribe
PostHog	Analytics for the iPhone and iPad app and the website, and the account events above
Sentry	Crash, hang, and performance reports from the iPhone and iPad app (from version 1.0.13)
UserJot	The feedback board, when you send feedback from the iPhone or iPad app
Microsoft Clarity	Website heatmaps and replays, only for visitors who opt in

Refund requests

When you ask Apple or Google to refund a Sumi purchase, the store may ask us about that purchase before it decides. RevenueCat, which processes our in-app purchases, may answer on our behalf. The answer says only whether the purchase was delivered, that Sumi lets you try it for free before you buy (the free starting pages), and whether we would prefer the refund to be granted or declined. It does not include your email, your name, what you read, or the sites you visit. The store makes the final decision and issues any refund itself; its own privacy policy covers that review.

Children

Sumi is rated 17+ on the App Store and is not directed at children under that age. The Android app is not directed at children either — it contains a browser that can open any website, so its Google Play listing is aimed at adults. We do not knowingly collect data from anyone under 13. The optional Clarity website notice is expressly limited to visitors aged 18 or older; visitors under 18 should select Not now.

Your rights

You can delete your account and the data attached to it yourself: in the iPhone and iPad app at Settings → your account → Delete account and data, or on the website at Settings → Security. Delete your Sumi account and data explains what is removed and what is kept, and how to ask by email if you cannot sign in.
You can delete the on-device library at any time from Settings → Delete all chapters.
For App Store purchases and subscriptions, use Apple's purchase management tools to view, cancel, or request refunds. For Google Play purchases and subscriptions, use Play Store → Payments and subscriptions → Subscriptions.
If you want a copy of any data we hold tied to your account, your device or your install identifier, or you want it deleted, email privacy@mangasumi.com.

Changes to this policy

We will update this page when our practices change. Major changes will also be announced in the app's release notes.

Sumi for iPhone and iPad

The app identifier

At first launch the app creates a random identifier for itself. It is not an advertising ID, it is not derived from your hardware, and it is not tied to your Apple Account. It is stored in the device's Keychain on that device only — it is not synced to iCloud — and iOS keeps it when the app is deleted, so reinstalling on the same device picks it back up.

The identifier is used to:

hold the device's own page balance and purchases while you are signed out (it is the id RevenueCat knows the install by);
prove that requests come from a genuine install, with Apple's App Attest;
count product events (see App analytics);
attach crash and performance reports to the install (see Crash and performance reports);
deliver the notifications you allow;
match an install that came from an Apple Search Ads campaign to a later purchase;
identify feedback you send from the app.

Signing in

Sign in with Apple — Apple shares your email address, or a Hide My Email relay address if you choose one, and, the first time, the name you choose to share.
Sign in with Google — Google's own sign-in page opens in a secure browser window. Google shares your email address, name and profile picture.
Email — we send a 6-digit code to the address you enter. It is valid for 10 minutes.

On a new install, cloud translation, free pages and purchases need an account; reading your own files, offline translation and Restore Purchases do not. If you used the app before Sumi accounts existed, signing in is optional.

The app keeps its sign-in, and the account's email address, name and picture link, in the device's Keychain on that device only. The picture is loaded from where it is hosted and kept in memory only. Sign out from your account in Settings.

The first time you sign in on an iPhone or iPad that already has pages, those pages are copied into your account, and an App Store subscription bought on that device is added to the account. The pages also stay on the device, for when you are signed out. Some pages bought in older versions of the app can only be used on the device they were bought on; the app tells you when that applies. A device's pages are copied into one account only, once.

If the account already has a subscription and the device has a different App Store subscription, the sign-in is undone and nothing changes: one account holds one subscription.

Purchases

Subscriptions, page packs and the offline buy-out are billed by Apple, and RevenueCat validates them. While you are signed in, the app sends us the purchase's transaction id, its product and Apple's signed record of the transaction, and the purchase is credited to your account. While you are signed out, it is credited to the device's own balance. The offline buy-out always stays with the Apple Account that bought it. We never see your card or payment details.

App analytics

The app sends product events to PostHog under the app identifier — never under your account, your email address or your name. The events cover: the app being opened (once a day), moving between its tabs, onboarding steps, your choice on the cloud-translation notice, sign-in being shown and completed (with the method used), the paywall being shown, a purchase being started and completed (with the product, not the price or the transaction), a translation starting, finishing, failing or being blocked (with a short description of the error), the rating prompt, and what you open on the Home screen.

PostHog adds the device model, screen size, iOS version, app version, language, time zone and network type (Wi-Fi or cellular). When a translation in the in-app browser fails, the event carries the domain name of the site (such as example.com — never the full address); when you open a title from the Home screen's catalog, it carries that title's id and the site it is on. There is no session recording, and taps and screens are not captured automatically.

Crash and performance reports

Starting with version 1.0.13, the app sends crash, hang, and performance reports to Sentry (Functional Software, Inc., United States) so we can find and fix problems. A report contains the stack trace, the app version and build, the device model and iOS version, the app identifier above, and a short trail of the screens and actions that led up to the problem. That trail is made of fixed names such as reader opened or translation succeeded — it never contains a manga title, a chapter name, a page image, the address of a site, or any text you read. The app also forwards Apple's MetricKit daily summaries (how the app exited, memory and hang figures) for the same purpose.

We do not send your email or name with a report, your IP address is not stored with it, and Sentry's session replay, screenshots, and view-hierarchy capture are switched off. Reports are tied to the app identifier only, so App analytics and these reports can be looked at together when you write to support. To have them deleted, email privacy@mangasumi.com.

Notifications

If you allow notifications, the app sends us its notification token with your language, time zone, app version and whether you want the daily-page reminder, so we can send that reminder in your evening and tell you about problems with the app. Turn notifications off in iOS Settings at any time.

Apple Search Ads

On its first launches the app asks iOS for an Apple Search Ads attribution token and sends it to us with the app identifier. We exchange the token with Apple for campaign-level data — whether the install came from a Search Ads campaign and, if so, the campaign, ad group, keyword, country or region and click date — and later match it to a purchase to learn which campaigns work. This uses no advertising identifier and does not track you across other companies' apps or websites.

Feedback

Feedback you send from the app goes to UserJot, our feedback board, with the title and message you write, the app version, the device model and iOS version, your translation settings, your page balance and, if you send it from the in-app browser, the address of the page you were on. The form says what is attached before you send it. Email us to have feedback deleted.

When you choose to share a before-and-after image or a translated PDF as a link, the image or the PDF and its title are uploaded to us, and anyone with the link can open it. The app also sends iOS's identifier for our apps, used only to limit how many links one device can create in a day. Share links are not attached to your account. To have one removed, email us the link.

What stays on the device

Imported chapters, your library, reading settings, offline models and the translation log in Settings → Diagnostics stay on the device. The log is never uploaded; you export it yourself if you want to share it.

Sumi for Android

The Sumi Android app is distributed on Google Play. Two things are worth saying up front. It has no offline engine: every translation it performs goes through the online tier described above. And it requires a free mangasumi.com account: you sign in once in your browser so the same pages work on the website, and so we can give you the daily free pages (one claim per account per day). Without signing in, the Android app does not open the reader.

The install identifier

At first run the app generates a random per-install identifier — the string and2_ followed by 32 hexadecimal characters. It is not an advertising ID, it is not derived from your hardware, and it is not tied to your Google account. The app does not request the AD_ID permission and contains no advertising or attribution SDK.

That identifier is used with Play Integrity to prove the install came from Google Play. It is not the page ledger. After you sign in, translation, balance, daily pages and purchases are keyed by your mangasumi.com account. The identifier lasts until you uninstall the app or ask us to delete it.

Checking that the install is genuine (Play Integrity)

When the app registers, and when its credentials are renewed, it asks Google Play services for a Play Integrity verdict and sends that verdict to us along with the install's public key. We use it for exactly one thing: to check that the install came from Google Play and is not an automated client minting free pages. An install that did not come from Google Play can fail this check. Google's own handling of that request is covered by Google's privacy policy.

Translating a page

What	When	Why we need it	How long we keep it
The image of the page you are translating	Each translation, in the built-in browser or in the reader	To transcribe and translate it	Discarded as soon as the response is returned; the text read from it and its translation are kept as described in What you translate
Your account, the target language, and a per-page charge key	Each translation	To charge the account once, and only once	The ledger entry (amount, timestamp, identifiers — never the image) is kept for billing

The request does not carry the address of the site you were reading. The app only sends images that are already on screen and that you asked it to translate; it never scrolls a page for you and never captures a whole page. Chapters you import from your own files stay on the device — only the single page being translated is sent, as an image.

The account

Signing in is required to use the Android app. It happens on mangasumi.com, not inside the app: the app shows a code, you approve it in your browser, and the app receives a token that can read your balance, claim the day's free pages, and spend pages on translation. The app then displays the email address, display name and profile picture of the account you signed in to. Until you sign in, the reader is not available. Sign out from the same screens.

A new account starts with 5 pages. After that, you claim 5 more each UTC day, once per account — every app, extension and the website share that claim. If you already have a Sumi account, sign in with that same account: its page balance and its plan come with it. A purchase you make in Google Play is added to that account. An account can have one active subscription at a time.

Purchases

Subscriptions and page packs bought in the Android app are billed by Google Play. We use RevenueCat as the processor that validates those purchases and tells us what to grant; the identifier RevenueCat is given is your mangasumi.com account id, not your email address. We never see your card or payment details.

What stays on the device

Imported chapters, bookmarks, recent sites, browser preferences, your target language and your reading settings are stored on the device only. Uninstalling the app removes them. The optional evening reminder is scheduled locally by the phone — there is no push token and no notification server.

What the Android app does not collect

No analytics. There is no product-analytics SDK in the app and no usage event leaves it. Our server's account events apply to every account.
No crash or diagnostics reporting. No Crashlytics, no Sentry, no equivalent.
No advertising ID, no ad SDK, no attribution SDK.
No location, contacts, calendar, messages, or audio.
No browsing history. Bookmarks and recent sites never leave the device, and a translation request carries no source URL.

Deleting Android data

Delete your Sumi account and data has the full procedure. In short: uninstalling the app ends the collection and removes everything held on the device; if you signed in, you can delete the account itself at mangasumi.com → Settings → Security; and you can email privacy@mangasumi.com without signing in.

Sumi Safari Extension

The Sumi Safari extension is included with the Sumi iPhone and iPad app and spends the same pages as the app:

When the app is signed in and the device's pages are in your account, the app hands the extension a short-lived sign-in of its own, and Safari translations use your account's pages and plan. Signing out of the app, or deleting the account, signs the extension out too.
When the app is signed out, the extension asks the app for the app identifier and a proof from Apple's App Attest, and Safari translations use the device's own balance.

Website session cookies are omitted from these requests, so a Safari translation cannot accidentally spend whatever account happens to be signed in to mangasumi.com in Safari.

The extension sends only the manga image you ask it to translate, the target language and an identifier used to prevent double charging — never the address of the page. On image hosts that block a normal extension fetch, the containing app may fetch the same displayed image on the extension's behalf. Images are processed for the requested translation and are not retained after the response.

Safari keeps extension preferences and a short-lived translation cache on the device. The extension has no analytics. If you use Report this site, it sends that site's domain name, the extension version and the platform. If the Sumi app has not been opened yet, or its pages cannot be read, the extension asks you to open Sumi.

Sumi Chrome Extension & Web Accounts

This section covers the Sumi Chrome extension and mangasumi.com web accounts — the same Sumi account the apps use. You can use the extension anonymously (a free daily quota) or sign in to your account for its pages.

How the extension translates

The extension translates the manga images on the page you choose:

On demand — when you click the Sumi icon and choose "Translate visible manga" or pick an image, only that page/image is translated.
Auto-translate (opt-in, per site) — you can turn auto-translate on for a specific website. The first time you do, Chrome asks you to grant access to that site. From then on, Sumi automatically translates the manga images on that site only as you scroll. You can switch any site off or remove it in the extension's options page, which revokes that access. Sumi never auto-translates a site you have not enabled.

To translate an image, the extension sends that image to our translation API at mangasumi.com. On a site you enabled auto-translate for, the extension also fetches the manga image files already shown on that page (from whatever host the page serves them) so it can translate them. No other sites are contacted; Sumi does not crawl sites, read page text other than the manga images, run analytics, or bypass paywalls.

What we collect

What	When	Why	How long
The manga images you translate (`image_b64`)	Each translation (anonymous or signed-in)	To perform the translation you requested	Discarded after the response is returned; a per-page idempotency key (not the image) is briefly kept so re-translating the same page doesn't double-charge
Account email	When you're signed in and the extension calls `GET /api/web/me`	Show your identity and balance in the popup	While your account exists
Credit balance + debits	When you translate while signed in	Show remaining pages and deduct credits fairly	Current balance in our database; the debit record (amount, timestamp, idempotency key — not the image) is retained for billing

What the extension stores on your device

In Chrome's local storage (chrome.storage.local), all local and non-personal: your target language, the "translate sound effects" toggle, the list of sites you turned auto-translate on for, an anonymous random device ID (for free-tier quota), and a short-lived cache of recent translations so the same image isn't re-translated. Signing in uses your normal mangasumi.com session cookie — there is no token to copy or paste.

What we do not collect

Your browsing history, or page contents other than the manga images being translated.
Anything from sites you have not turned auto-translate on for.
Location data, passwords, or analytics on what you read.

Revocation

Turn auto-translate off for a site (or remove it) in the extension's options page — this revokes Sumi's access to that site. Sign out in the extension, or uninstall it, to clear all local data.

Web checkout and credit purchases happen only on mangasumi.com (Stripe) — the extension never collects payment details.

Signing in with Google

You can create or access a mangasumi.com web account with Sign in with Google, including Google One Tap — a prompt that may appear on our sign-in and registration pages so you can continue with a Google account you are already signed in to. Choosing it loads Google's sign-in components (Google Identity Services / FedCM) on those pages — third-party scripts provided by Google — and Google processes the sign-in information involved (such as verifying your Google account and returning your email, name and profile picture) under Google's Privacy Policy.

We use what Google returns only to authenticate you, create or open your account, and show you which account you are signed in to — nothing else. The One Tap prompt appears only on our sign-in and registration pages, never on marketing or reading pages; you can ignore or dismiss it and sign in another way. It is not used to profile you or to track what manga you read.

Contact

privacy@mangasumi.com