Sumcheck — Privacy Policy
Last updated 19 August 2026
Sumcheck does not collect, store or transmit any user
data. There is no server, no account, and no analytics. This is not a
promise about how we handle your data — it is that we never receive any.
What happens to your documents
All conversion happens locally, inside your browser. Files you convert,
pages you capture and the resulting output never leave your device. The
extension makes no network requests while running: every component it needs —
the PDF engine, the OCR engine and its language data, the word lists — is
bundled inside the package.
Converted output exists in the tab until you download or discard it.
What is stored on your device
- Your settings, in
chrome.storage.local, so
they persist between sessions. Local to your browser; not synced to a Google
account, not transmitted.
- A page you capture, briefly, in
chrome.storage.session, so the converter tab can read it. These
entries are discarded within five minutes and never leave the browser.
Site access
Sumcheck requests no host permissions at install time. If you use
Convert linked file, Chrome asks your permission for that one site so
the file can be fetched and converted. That request is made to the site
hosting the file, by your browser, at your instruction — nothing is sent to
us, because there is no "us" to send it to.
How you can check
You do not have to take any of this on trust. Sumcheck is open source under
the Apache License 2.0, and the claim is enforced rather than asserted:
- Chrome's Manifest V3 content security policy blocks remotely hosted
code; the extension ships with
script-src 'self'
'wasm-unsafe-eval'.
- The build fails on any remote script reference
(
npm run check).
- Every dependency is vendored in the package and listed, with its
licence, in
THIRD_PARTY_NOTICES.md.
- An automated check asserts the shipped manifest is refused when
it tries to read a page without an explicit user action.
Read the source: github.com/mshresponse/sumcheck
Children
Sumcheck collects no data from anyone, of any age.
Changes
If this policy ever changes, the updated date above changes with it and the
revision is visible in the repository's history.
Contact
sumcheck@everythingvirtually.com