The profiler for agents and humans.

Find it, fix it, share it. Any running program, no code changes.

curl -fsSL https://perfr.dev/install.sh | sh

The service runs on Linux, macOS and Windows. The viewer runs in any browser.

The evolution of Orbit, from its original author.

Works with

Drag to pan · wheel over the ruler to zoom · click a thread · right-click a scope · Home to fit Open it on its own

4.6 MB stream

Coming soon Sharing a capture with a link, and annotating it.

What perfr is

A profiler for a program that is already running. A person and an agent look at the same capture: where the time went, and whether a fix moved it.

In the manual

Linux, macOS, Windows

perfr

On the machine you profile

It attaches to a process that is already running. You do not rebuild that process, and you do not relaunch it.

The same view

  • Desktop
  • Tablet
  • Phone

Any device with a browser can open it, including one that is not the machine being profiled. A saved capture also opens with no service at all.

  1. Find it

    See the hot function

    Attach and record. The flame graph shows where the run spends its time, with nothing added to the program.

  2. Fix it

    Change your program

    The fix is yours. Capture again, and read the same flame graph. That pair is the before and the after.

  3. Share it

    One capture, any browser

    The timeline and the flame graph open on any device. A saved capture needs no service. A link to send someone is coming soon.

The command is at the top of this page. The recordings are on the features page.

About

The evolution of Orbit, from its original author: the same DNA, with new capabilities. The capture agent and the web viewer are the work in this repository.

Site built 2026-11-06 at commit b80a744. Recordings are of the live viewer at da8aa05c, profiling game_loop. The embedded capture is a .perfr.stream.