---
title: "How it works"
description: "What happens to a document from the moment you open it, what you get back, and what the certificate says."
canonical: https://keepitlocal.app/how-it-works
last-updated: 2026-09-13
---

# How it works

What happens to a document from the moment you open it, what you get back, and what the certificate says.

Six things happen to a document, all of them inside your browser.
- Open: You choose the file. It is read inside the tab, and nothing is sent.
- Read: A scan or a photograph is read as a picture first, in a language chosen for you.
- Find: The detectors mark what they know. Your search terms and your template apply too.
- Approve: Accept or reject each mark, accept a whole kind at once, or draw your own box.
- Export: A page is rebuilt as a picture with the marks burned in. Other files are rewritten in place.
- Check: The new file is read back and checked. A failed check stops the export.

What you get back:
- The redacted file: In the format it went in as.
- A report: What was covered, how much, over how many pages.
- A certificate: The signed record, which you can hand over on its own.
- One zip: The three together, so nothing is sent alone by accident.

What the certificate says:
- The file that went in: A fingerprint of it, not the file and not its name.
- The file that came out: The same, taken after the export.
- When: The moment it was issued.
- How much: Marks applied, and pages.
- Which version did the work: The version of the program that made the file.
- Whether it passed its checks: How many checks the file was read back against.
- Who approved it: Present when your workspace requires a second person.

How anyone checks it:
- Open the address printed on the certificate.
- The page says whether we signed it, and shows what the signature covers.
- No account, and the file is never uploaded to check it.