postMessageObserver

by yishiashia · Developer Tools

FeaturedManifest V3 Free

View in Chrome Web Store Data as of 15 Oct 2026

A Chrome extension that allows you to observe the flow of postMessage messages on the side panel.

Users

961

+5 in 30 days

Rating

5.0 / 5

unchanged in 30 days

Ratings

0 in 30 days

Store rank

#32K

#27K among extensions

Version

1.0.0

updated 24 Oct 2023

Users

monthly, 3 years

Latest, 15 Oct 2026: 961 usersMove the mouse over the chart for any month

Ratings count

monthly, 3 years

Latest, 15 Oct 2026: 1 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About postMessageObserver

Chrome PostMessage Observer provides a convenient side panel to view postMessages for the current page. This extension offers a user-friendly UI that simplifies the debugging and observation of message flows between iframes and the top window. Easily intercept and analyze postMessage messages, view their payload, source, and target details, and efficiently troubleshoot communication issues within web applications. Contributions are welcome to the GitHub project, which can be found here: https://github.com/yishiashia/chrome-postmessage-observer