Qt, Linux and Everything: Debugging Qt Webassembly
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The debate around Qt WebAssembly's potential as a cross-platform application target sparked a lively discussion, with some commenters eagerly anticipating its maturity, while others expressed reservations about relying on browsers as the primary target. As the conversation unfolded, it veered into related topics, such as the possibility of using WASI runtimes and the current state of Qt on macOS, with the Qt for macOS maintainer chiming in to assure that the framework is adapting to the latest Mac UI refresh. Notably, some developers shared their experiences using Qt for macOS app development, highlighting its continued relevance. The thread's relevance lies in its exploration of the evolving landscape of cross-platform development and the role Qt plays in it.
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- 01Story posted
Dec 9, 2025 at 4:19 PM EST
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This is the kind of thing that I feel is very nice and terrible at the same time. Yes it is convenient but it is also such a complex piece of software, it's sad that it is required to run gui apps. Ok, it may not be required yet per say, but I have mixed feelings about this direction.
We've tweaked our styles to take the new design metrics into account, and fixed or worked around issues where we've seen them. We don't integrate with NSGlassEffectView and friends yet. If you find any issues in recently released version of Qt 6.10, 6.8 or 6.5, please report them upstream, thanks!
See also https://www.qt.io/blog/qt-on-macos-26-tahoe
Thank you for replying, glad to hear that Qt is staying on top of the game, I know it's a tough job.
This indie dev (uses Qt) shows the process for updating icons to the latest UI refresh https://successfulsoftware.net/2025/09/26/updating-applicati...
[1] https://get-notes.com
Debugging wasm qt apps is not hard at all. Yes, as the article says, you need to build the code in debug mode, this isn’t unusual.
If you use qtcreator, it’s, and I hate this word, trivial. Most of the work comes from setting up the qt kit in qtcreator… which takes about 5 minutes.
Breakpoints just work. Debugging just works. Everything… works.
...and you're actually debugging the WASM executable which runs in a browser and not a native version of the application?
Not that it matters most of the time, I also do 99% of my debugging session on the native target. But for debugging problems that only happen in the WASM version actually debugging the WASM version makes a lot of sense, and that was anything but trivial not too long ago.
I’m not a professional webdev, I was just messing around with qt+wasm for a few weeks a little while ago.
And as QtCreator is first-class citizen for everything related to Qt, you'll have all the Qt types correctly resolved/unrolled/displayed/annotated by gdb, which makes your debugging experience a lot, lot more convenient.
What makes this particularly interesting is the technology stack: Emscripten embeds DWARF debugging symbols (the same format used for native Linux binaries) directly into WebAssembly binaries. A Chrome browser extension then reads these embedded symbols and reconstructs the original C++ source code view in the DevTools, mapping the compiled WebAssembly back to your Qt C++ source with full directory paths intact.
All of this would have seemed impossible not long ago.
So it doesn't work in any other browser? More incentive for those web 4.0 or 5.0, i lost count, "experts" to only support Chrome?
It has stopped being the Web long time ago.
https://floooh.github.io/2023/11/11/emscripten-ide.html