Get some info about registered plugins in the current profile
For now its just experiments.
Open the plugin inspector via the dev tools panel (F12).
Plugin Inspector ships with multiple profiler backends. Toggle profiling with the Profiler button in the toolbar, then stop it to collect and view the results. Enable or disable individual profilers via the Settings action.
Most profilers and interactive vizualisation tools have to be installed manually
pip install pyinstrument snakeviz yappi viztracer
When multiple profilers are active at the same time, they will profile each other. Running more than one profiler simultaneously is not recommended.
| Type | Statistical (sampling) |
| Install | pip install pyinstrument |
| Output | Interactive HTML report opened in browser |
| Visualization | Built-in HTML renderer |
| Docs | pyinstrument.readthedocs.io |
pyinstrument samples the call stack at regular intervals rather than tracing every function call. This makes it lightweight with low overhead and ideal for getting a quick, high-level view of where time is spent. Because it samples rather than traces, short-lived calls may be missed — but the overall picture is usually accurate and easy to read.
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| Type | Deterministic (tracing) |
| Install | Built-in (Python standard library) |
| Optional | pip install snakeviz for interactive visualization |
| Output | .prof and .txt files; snakeviz browser UI if available |
| Visualization | snakeviz (sunburst / icicle) |
| Docs | docs.python.org/3/library/profile.html |
cProfile is Python's built-in deterministic profiler. It records every function call and return, giving exact call counts and cumulative timings. The trade-off is higher overhead compared to statistical profilers. When snakeviz is installed it opens an interactive sunburst visualization in the browser; otherwise a text summary is shown.
| Type | Deterministic (tracing), multi-threaded |
| Install | pip install yappi |
| Optional | pip install snakeviz for interactive visualization |
| Output | pstat-compatible .prof and human-readable .txt; snakeviz browser UI if available |
| Visualization | snakeviz (sunburst / icicle) |
| Docs | github.com/sumerc/yappi |
yappi profiles all threads, not just the main thread, and supports both
wall-clock and CPU-time modes. In wall-time mode it captures everything that
happens during nested event loops (e.g. QDialog.exec()), making it
particularly useful for understanding what QGIS does while a modal dialog is
open.
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| Type | Full call-stack timeline tracer |
| Install | pip install viztracer |
| Output | JSON trace file; interactive timeline via vizviewer |
| Visualization | vizviewer (Perfetto-based timeline) |
| Docs | viztracer.readthedocs.io |
viztracer records every function call chronologically across all threads and renders the result as an interactive timeline. This is the most detailed view available — ideal for understanding ordering, concurrency, and nested event-loop behaviour. The downside is significantly higher overhead and larger output files. Many aspects of the trace can be tuned in the profiler settings (stack depth, argument logging, minimum duration filter, etc.).
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