extension ExtPose

postMessage debugger

CRX id


Description from extension meta

This extension prints messages sent with postMessage to the console

Image from store postMessage debugger
Description from store This chrome extension prints messages sent with postMessage to the console for debugging.

Latest reviews

  • (2023-11-12) Валентин Ткачев: Thank you, very convenient for development process.
  • (2023-01-30) E. Donker: This extension is great! Use it a lot.
  • (2023-01-20) Matt P: I was pleasantly surprised that this reports messages sent to iframes as well as messages received by the top frame as well. As others said, if you don't see anything in the devtools console, you probably need to pull out the sidebar to look at the verbose/debug log level. A good example case is the youtube embed API (you can find examples on codepen). It would be very helpful if this logged a bit more information about each MessageEvent rather than just the data...like the origin, source, ports and lastEventId. Currently it seems to log the window title, but perhaps the window url or origin would be more useful.
  • (2022-12-26) Elías Daniel Araya Díaz: This is not working at all 👎
  • (2021-06-30) Edouard Lopez: Work as expected and log event, but I wasn't able to toggle off the logging other than disabling the whole extension.
  • (2021-04-20) John Horner: Very useful extension, but the thing about selecting 'verbose' in the Console's 'levels' box ought to be more prominent! It should be in the description of the Extension: "This extension prints messages sent with postMessage to the console (turn on Verbose levels to see them)"
  • (2020-10-08) Danilo Hoss: very helpfull :)
  • (2020-08-17) Alberto Blacutt: Nice tool... works great
  • (2020-01-08) Oliver Jones: This works nicely and does what I need. Others have mentioned setting "Verbose" in "Default Levels". It's also helpful to choose the appropriate context from the pulldown (just to the left of the eyeball) in the top bar of console.log Suggestions for improvement, if you have time: 1) log the postMessage events from / to all contexts, not just the chosen one. 2) use some sort of log level that doesn't require messing with Default Levels, if possible. These things would make it easier for me to ask my customers to use it to troubleshoot message posting between iframes (mine) and parents (theirs). Again, thanks for this extension. It's really useful.
  • (2019-10-18) Pike96: Convenient tool! I was about to write one, it saves my time. For guys not seeing the log, Check 'Verbose' in Console tab's top bar 'Default levels'
  • (2019-08-22) Eric Eldard: Works as advertised (logs to debug, so make sure to set console log level to Verbose). Inspected the source code on 8/22/19 and as of now it's not doing anything malicious (no file downloading, no posting your data, no analytics tracking). Thanks for a very helpful tool!


4,000 history
4.5833 (12 votes)
Last update / version
2018-11-28 / 0.2.0
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