How to debug SWF in browser?

Has anyone had any luck getting the Flash debug player to work in current versions of Chrome or Firefox? Any tips on how to at least get FP crash traces to display on the browser console? Or even better, getting an Animate debug session to connect to FP in a current browser? Thanks!

see Flash Roadmap
also Manage Flash in your users’ Chrome Browsers

Flash Disabled by Default (Target: Chrome 76+ - July 2019)


Flash will be disabled by default, but can be enabled in Settings at which point explicit permission is still required for each site when the browser is restarted.


Require affirmative user choice to run Flash Player.

Announcements/ Artifacts

Flash Support Removed from Chromium (Target: Chrome 87+ - Dec 2020)


Flash support/ capability will be removed from Chromium.


Align with Adobe’s announced plan to end support.

Announcements/ Artifacts

  • TBD

also see previous posts

you need to enable flash logs with mm.cfg, see Adobe docs

Now I would say it depends what you need to test etc.
for some things running the Flash Player projector content debugger can be enough
eg. Adobe Flash Player Support Center - Debug Downloads

with the big advantage that you will not need the browser to test

It had become quite complicated to test Flash in the browser,
and if you build an Adobe AIR app just use ADL (Adobe Debug Launcher)

so my question do you want to test in the browser by habit or is it really a need to publish (and so debug) a SWF file meant to run in the browser ?

I’m afraid I do need to publish the SWF to be run in the browser. (We are in the process of migrating, but for now, I still need to deliver content to my users via the browser.) Debugging individual SWFs with Animate works fine, but for various reasons we need to be able to open local SWF files via browser. I can manually trace to the browser console with ExternalInterface but I want to see all FP crash dumps too (at a minimum).

The links you referred to are great, thank you, but several seem to be obsolete (e.g. chrome://plugins/ doesn’t work…)

those are for reference, eg. at the time when I looked into the problem
so yeah some things have probably changed

but the general idea should work

  • find out the available chrome flags
  • launch chrome with a series of flags and see if it works

I don’t have something that I’m sure is working right now
because it’s been many months I don’t target SWF for the web

I use a small java applet called “Vizzy Flash Tracer” to read the output, Chrome uses a log file located at “Users[USER]\AppData\Local\Google\Chrome\User Data\Default\Pepper Data\Shockwave Flash\WritableRoot\Logs\flashlog.txt”. Hope that helps.