Profiler: Start

Use this action to start the profiler for the specified number of seconds. It collects a set of statistics that show how much time each part of Home Assistant takes, which helps you track down a performance issue or a misbehaving integration.

This action requires an administrator account.

Using this action from the user interface

If you prefer building automations and scripts visually, Home Assistant walks you through this action step by step. You pick what to target, tweak a few options, and save. No YAML knowledge required.

To start the profiler from an automation or a script:

1. Go to Settings > Automations & scenes.
2. Open an existing automation or script, or select Create automation > Create new automation.
3. If you’re setting up a new automation, add a trigger in the When section. Scripts don’t need a trigger. They run when something else calls them.
4. In the Then do section, select Add action.
5. Search for and select Profiler: Start.
6. Optionally, set the number of Seconds to run the profile.
7. Select Save.

Options in the UI

Using this action in YAML

If you work directly in YAML, or you want to know exactly what Home Assistant does under the hood, this section has the technical reference. It lists the field names you use in YAML, their types, and which ones are required.

In YAML, refer to this action as profiler.start. A basic example looks like this:

action: profiler.start
data:
  seconds: 120

This runs the profiler for 120 seconds.

Options in YAML

This action does not support targets.

Good to know

When the profile is complete, the profiler generates a Python cprof file and a callgrind.out file in your configuration directory. The exact path to these files appears in a notification, so you can find and copy them.

To view a cprof file, use:

• SnakeViz
• Gprof2dot

To view a callgrind.out file, use:

• KCachegrind or QCachegrind
• Gprof2dot

The gprof2dot tool generates DOT files, which you can convert to images using the dot tool from Graphviz, or view directly with xdot. The -e and -n parameters set the minimum percentage required to include a function in the output file. For example:

• To generate the DOT files:

Try it yourself

Ready to test this? Open Developer tools > Actions, search for this action, fill in the fields, and select Perform action. You see what happens on your actual entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more] without writing a line of YAML.

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with the action you’re calling and what you expected to happen, or share on our subreddit /r/homeassistant.

Related actions

These actions work well alongside this one:

• Profiler: Memory: Starts the memory profiler for a set number of seconds.

• Profiler: Start log objects: Starts logging the growth of objects in memory.

• Profiler: Dump log objects: Logs the representation of objects of a given type in memory.