Stop the Monosnap memory leak — switch in 60 seconds

The leak is not your computer

If you've been wondering whether it's your machine — an old driver, Windows 11 oddities, a runaway Chrome tab — it isn't. The leak is inside Monosnap and has been for years. Search r/monosnap and you'll find thread after thread describing the same pattern.

Here's what happens under the hood. Each time Monosnap captures a region, it allocates a frame buffer large enough to hold the raw pixel data. For a 2560 x 1440 screen that's roughly 14 MB. When the editor closes, those buffers should be released back to the OS. In Monosnap, they often aren't — they're retained by the Electron renderer's heap, waiting for a garbage-collection pass that either never runs or runs too late. Over a workday of 40+ captures, the retained buffers accumulate into hundreds of megabytes of phantom RAM.

The fix is a different app

Monosnap's architecture ties the leak to Electron itself, and patching it would require rewriting the capture pipeline. That rewrite hasn't happened in five years. The practical fix is a tool that was designed without the problem in the first place.

Maxisnap is built on PyQt6 and compiled with PyInstaller into a single Win32 executable. There's no Chromium process. Each capture allocates a QImage, the editor references it, and when the window closes the reference is dropped and the memory returns to the OS immediately — because PyQt's ownership model and Python's reference counting both release eagerly rather than waiting for a generational GC.

Empirically: Maxisnap idle at launch is around 50 MB. After 72 hours of continuous running with regular captures, it's still around 50 MB. The chart above is from actual logs.