Using Wasmtime's cross-platform profiler

The guest profiling strategy enables in-process sampling and will write the captured profile to a file which can be viewed at

To use this profiler with the Wasmtime CLI, pass the --profile=guest[,path[,interval]] flag.

  • path is where to write the profile, wasmtime-guest-profile.json by default
  • interval is the duration between samples, 10ms by default

When used with -W timeout=N, the timeout will be rounded up to the nearest multiple of the profiling interval.