Trace Spy is a compact portable tool which captures and displays debug output on your PC (highly technical status messages from running applications). It's essentially a .NET version of Sysinternals DebugView, with filtering, trace colorization via regular expressions, and basic Event Tracing for Windows support.

The good news: Trace Spy is extremely easy to use: just launch it and messages will be appear in real time.

The bad news, for regular users: as you'll guess from the description, this is a developer-oriented tool; most programs don't generate any debug output, and when you do see a message it'll probably be extremely cryptic. We regularly saw messages like "explorer 11872 0000000000000000 LEAVE: DllCanUnloadNow" and "SearchProtocolHost JIT-V : New Virtualized Thread: 16672", for example - not particularly helpful.

Still, there are occasional exceptions.

When right-clicking a folder on our test system, Explorer generated a debug message complaining that it "failed to load resource DLL...", and pointed to an Apple file, maybe useful if a folder wasn't displaying as you expected.

We noticed that Google Earth displayed some status information when it launched: Intrinsic Alchemy version, EGL version, vendor strings and more. Even if you've no idea what any of this meant, you could perhaps compare the debug output on this PC with a working system, and look for any differences.

Running VLC Media Player on our test system also produced some unusual debug output, including a warning of an "ES_OUT_RESET_PCR" error. We've no idea what that means, but if we were having a VLC problem then it could be a valuable clue, and a quick web search would tell us more.

You shouldn't expect too much from Trace Spy; barely 5% of our test programs displayed any debug output, and most of that is too cryptic to be useful. But there are one or two exceptions, and on balance (and if you're an experienced PC user), it's probably worth adding Trace Spy to your troubleshooting toolkit.

Version 2.1 changes:
 - Added ETW description into process name (option).
 - Added Quick Colorizers feature.
 - Added RecordView (double click on a trace).
 - Added support for ETW trace levels (the 2nd parameter in the WriteMessageEvent call above)
 - Added support for TAB '\t ' character in trace texts.


Trace Spy provides a simple and straightforward way to monitor debug output. It's very much a developer's tool, but if you're an experienced PC user - you know your way around the darker corners of Process Hacker, say - then the program might occasionally help with your troubleshooting.