PII Pseudonymizer

Browser extension

Paste text into ChatGPT, Claude or Gemini as usual. The extension replaces names, addresses, ID numbers and other personal data before the text reaches the chat, and gives you the real values back when you copy the answer.

It runs entirely in your browser. The detection engine is part of the extension; it makes no network requests at all, not even to Kwizmo. You do not have to trust our servers, because your text never reaches them.

Download for Chrome, Edge, Brave Download for Firefox

How it works

  1. Paste. When the pasted text contains personal data, the chat receives a protected version, and a short notice shows how many values were replaced. Ctrl+Z undoes it. In the settings you can choose to be asked first.
  2. Ask. The AI works with realistic fake names and numbers, so its answer stays natural.
  3. Copy the answer. Select the answer and copy it: the clipboard gets the real values, also in grammatical forms the AI invented. Or click Show real data, which appears when you select text with fake values.

More ways to use it:

  • Alt+Shift+P or right-click → Protect personal data in this field protects text you have typed. This also works on any other website.
  • Alt+Shift+R or right-click → Show with real values for a selection.
  • The toolbar button protects or restores any text you paste into it.

The same person keeps the same fake name for the whole browser session on a site, so follow-up questions work. The engine is the same as on this website, including the machine-learning detector for names without cues; see the measured accuracy.

Installation

Until the extension is published in the browser stores, install it manually:

Chrome, Edge, Brave, Opera

  1. Download the file above and unzip it into a folder you keep.
  2. Open chrome://extensions (Edge: edge://extensions) and switch on Developer mode.
  3. Click Load unpacked and choose the folder.

Firefox (version 128 or newer)

  1. Open about:debugging#/runtime/this-firefox.
  2. Click Load Temporary Add-on and choose the downloaded zip file. Firefox removes temporary add-ons when it restarts; a signed version will follow.

Sites

Protection when pasting is on for ChatGPT, Claude, Gemini, Microsoft Copilot, Mistral Le Chat, Perplexity and DeepSeek. You can switch it off per site and add other sites, such as your company's own AI tool, in the settings. The browser asks for permission for each added site.

Privacy and permissions

  • No network access. The extension contains no code that sends data anywhere, and its security policy forbids connections.
  • Replacement lists are kept in the browser's memory and are gone when you close the browser. You can choose to keep them longer, or delete them any time.
  • Names you enter in the settings stay on your computer. Other settings sync with your browser account.
  • Permissions: access to the listed AI sites (to see what you paste and copy there), storage, the right-click menu, and access to the current tab only when you use a shortcut or the menu.

Limitations

  • Files and images you upload to the chat are not checked.
  • Text you type directly is protected only when you press the shortcut.
  • Detection is automatic and can miss things. Glance at the notice's Details before you send something sensitive.
  • If a chat site changes how its input box works, pasting may need an update of the extension.

For companies

Companies can install the extension for all employees through browser policies (Chrome and Edge ExtensionSettings, Firefox policies.json) and preset names to replace, words to never replace, the paste behaviour, the language and the detectors (managed storage keys knownNames, neverReplace, mode, locale, disabled). For applications that call AI models directly, use the LLM gateway. See the business plans.