Kitsumi browser extension
Last updated: 7 September 2026


Kitsumi has no accounts, no servers, and no analytics. Everything it stores,
it stores in your own browser. It makes network requests only when you use a
feature that needs one, and every one of those is listed below.

On a fresh install, nothing you type, hover, watch or listen to is sent
anywhere. The features that would send something are off until you turn them
on.


All of the following is kept locally in your browser, using extension storage
and IndexedDB. None of it is transmitted anywhere.

• Your settings: subtitle appearance, position, timing offsets, per-show sync
  offsets, interface preferences, allowlisted sites.
• Your study data: words you have looked up, words marked as known, study
  time, streaks, active days, ranks and achievements, per-language statistics.
• Dictionaries you install, stored as local databases.
• Subtitle files you load, for the duration of playback.
• Recognition data for any OCR language you have used, cached after its first
  download.
• API keys you choose to enter for optional third-party services.

You can delete all of it at any time by removing the extension, or by using
the reset controls in the extension's settings.


Kitsumi does not contact any server operated by the developer, because none
exists. It contacts third-party services only in response to an action you
take:

| You do this | Kitsumi contacts | What is sent |
| :--- | :--- | :--- |
| Search for subtitles | Jimaku, OpenSubtitles or SubDL, whichever you have set up with your own key | The show title taken from the page, or the terms you typed |
| Search for subtitles | Kitsunekko | Nothing. Kitsumi fetches its public directory index and matches your show against it on your device |
| Download a dictionary | GitHub Releases, Hugging Face and the other hosts named in the dictionary catalog | A file request. No personal data |
| Look up a word online, off until you turn it on | The dictionary service you selected | The word you looked up |
| Play a word's pronunciation | assets.languagepod101.com | The word and its reading |
| Read text from an image | Nothing, for Japanese vertical text. For any other language, tessdata.projectnaptha.com | The name of the language. The picture is recognised on your device and never leaves it |
| Generate subtitles with AI, optional | Groq | The audio of the video or file you chose, plus your own Groq API key |
| Enable AI definitions, optional | Groq | The word and the subtitle line being worked on, plus your own Groq API key |
| Enable AI imagery, optional | WaveSpeed | The prompt text, plus your own WaveSpeed API key |
| Mine a card to Anki | AnkiConnect on http://localhost:8765 | The card contents, including a screenshot or clip if you turned those on. This request never leaves your computer |

Online dictionary lookups are off on a fresh install. Until you switch them
on, every lookup is answered from the dictionaries stored on your device, with
no network request at all. You can turn them on from the welcome page or in
the Dict tab, and turning every source off again switches them back off.

Subtitle providers need a key of your own. Kitsumi ships no shared key.
Jimaku, OpenSubtitles and SubDL each stay dormant until you enter one, so none
of them is contacted until you decide to set it up. Kitsunekko needs no key,
and it receives no search terms.

The AI features are off by default and stay dormant until you enter your
own API key. With no key present, no request is made to Groq or WaveSpeed at
any time.

About the OCR download. Japanese vertical recognition works entirely
offline; its data ships inside the extension. Any other language downloads its
recognition data once, from tessdata.projectnaptha.com, and keeps it on your
device afterwards. The only thing sent is the name of the language. In the
Opera version of Kitsumi this also applies to Japanese, because Opera's store
does not accept that file type in a package. What is downloaded is recognition
data, not program code, and none of your images or text is uploaded for it.

Each third-party service handles the data it receives under its own privacy
policy. If you enable one of these features, you are choosing to send that
content to that provider, under your own account where a key is involved.


Kitsumi requests access to all sites because subtitles have to be rendered
over video players it cannot know about in advance, including players inside
embedded frames. It reads the page only to find the video player, its subtitle
track, and any image you point the OCR at, and only on pages where you use it
or that you have allowlisted.

Kitsumi does not collect page content and does not transmit it, with one
exception that is entirely in your hands: if you switch on an AI feature with
your own API key, the subtitle line, or the audio of the video you asked it to
transcribe, is sent to that provider so it can do the thing you asked for.
Nothing else from the page is ever transmitted, and none of it is ever stored
outside your browser.

If you would rather narrow this, both browsers let you restrict an extension
to specific sites:

• Chrome: right-click the extension icon, "This can read and change site
  data", "On specific sites".
• Firefox: Add-ons Manager, Kitsumi, Permissions.

All features continue to work on the sites you allow.

• No user accounts, sign-in, or registration.
• No analytics, telemetry, crash reporting, or usage tracking.
• No advertising and no advertising identifiers.
• No cookies. Kitsumi neither sets nor reads any.
• No selling or sharing of data.
• No transmission of your study history, vocabulary, or statistics anywhere.
• No sending of your API keys to anyone but the service that issued them.

Kitsumi is a general-purpose study tool and does not knowingly collect data
from anyone, including children.


Material changes to this policy will be published in this file, and its
"last updated" date will change. The version history is public in this
repository.


Questions about this policy: olexifyyy@gmail.com
Or ask in the Discord.