A/B Spy privacy policy

Last updated 31 October 2026

A/B Spy is a Chrome extension that shows the A/B tests a website is running. In short: it collects no data about you, and nothing it reads ever leaves your browser.

What the extension reads

On the web pages you open, A/B Spy reads the test settings that testing tools such as Optimizely or VWO have already sent to your browser. It turns them into a list of tests and versions that you can see in the extension's popup.

Where that information goes

Nowhere. The list is kept in your browser's temporary session storage, one entry per open tab, and is deleted when you close the tab or the browser. A/B Spy has no server, no analytics, no tracking and no account. It does not sell, share or transfer any data, because it never has any.

What it does not collect

• No personal information, such as your name, email address or location.
• No browsing history. It does not keep a record of the sites you visit.
• No page content, form entries, passwords, cookies or messages.

Images in the popup

When a test version uses a new image, the popup shows a small preview loaded from the website's own image address, the same way the website itself would load it. No referrer is sent with these requests.

Permissions

• Access to websites: needed to read the test settings on the page you are viewing.
• Storage: keeps each tab's list until you close the tab.
• Scripting: lets the popup check tabs that were already open before you installed the extension.

Changes and questions

If this policy changes, the new version will be posted on this page with a new date. For questions, open an issue on the A/B Spy project page on GitHub.