DESKTOP VS BROWSER-ONLY
Desktop app vs browser-extension-only redaction
A browser extension is the most convenient place to catch a risky prompt, and the most limited place to do the actual work. DataAnonymiser uses both: an extension for the moment of typing, and a desktop app for everything a browser cannot reach.
Side by side
The differences that matter.
Compared at the level of the category, not a specific vendor's current feature list.
| Dimension | Browser-extension-only tool | DataAnonymiser |
|---|---|---|
| Text typed into a web AI tool | Covered | Covered, by the companion extension |
| PDFs, DOCX, XLSX | Not covered | Covered by the desktop app |
| Images and screenshots | Generally not covered | Covered by the desktop app |
| Whole folders | Not covered | Folder DLP scan with per-file and per-category reporting |
| Desktop AI apps and non-browser tools | Not covered — the extension cannot see them | Covered: anonymize in the app, paste anywhere |
| Detection engine | Limited to what can run inside a browser tab | Runs in the desktop app, with far more room to work |
| Extra install required | No — extension only | Yes — desktop app, with the extension as an optional companion |
The browser only sees the browser
An extension can read and rewrite what you type into a page, which makes it excellent at the specific moment a prompt is about to be sent. What it cannot do is open the contract sitting in your Downloads folder, read the screenshot you were about to attach, or protect you in a desktop AI client that is not a web page at all.
If your entire workflow lives in a browser tab, an extension may be all you need. Most professional workflows do not: the sensitive material arrives as a PDF, a spreadsheet, an exported ticket log, or a photo of a document.
Why the engine belongs outside the tab
Anything running inside a web page has to share that tab's resources and stay small enough not to make typing feel sluggish. That puts a ceiling on how thorough the detection can be.
DataAnonymiser does the work in the desktop app, where it has room, and lets the browser extension call it on the same machine. You get the extension's convenience with the desktop app's engine, and the text still never leaves the machine.
How the companion extension works
The extension has two modes. On demand: select text on any page, open the toolbar popup, and the desktop app anonymizes it locally. Live watch: on ChatGPT, Claude, Gemini, Gmail and Outlook, it checks what you type or paste and warns when it spots personal data, with one-click anonymize; while the warning shows, the site's send button is paused. In ChatGPT, Claude and Gemini, a Restore button then puts the real details back into the answer.
The two talk to each other only on your own computer, through a connection you set up yourself and can switch off. It is disabled by default, and no traffic leaves the machine.
Questions
Common follow-ups.
Do I have to install the browser extension?
No. The extension is an optional companion. The desktop app is fully usable on its own — you paste or open content, anonymize, and copy the safe version wherever you need it.
Does the extension send my text to a server?
No. It talks to the DataAnonymiser desktop app on your own machine, and nowhere else. If the desktop app is not running, the on-demand mode simply does not work; nothing is sent anywhere else.
Which sites does the live watch cover?
ChatGPT, Claude, Gemini, Gmail and Outlook. The on-demand popup mode works on any page where you can select text.
Related
Other comparisons.
ON-DEVICE VS CLOUD
On-device redaction vs cloud redaction APIs
Why sending data to a cloud service to have it de-identified creates the exposure you were trying to avoid.
APP VS LIBRARY
A finished app vs a self-hosted redaction library
Open-source toolkits are free and flexible. This compares the total cost of owning one against a finished local app.
REDACTION VS SETTINGS
Redaction vs relying on the AI vendor's privacy settings
Opting out of training is a promise about what happens to your data after it lands. Redaction changes what lands.
DataAnonymiser is a best-effort redaction tool, not legal advice. It does not guarantee detection or removal of all personal data, nor compliance with GDPR, CCPA or any other law. Always validate outputs against your own obligations.