> ## Documentation Index
> Fetch the complete documentation index at: https://docs.browspark.krishm.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# devtools_profile

> CPU profiler.

CPU profiler. start/stop a sampling profile (.cpuprofile artifact, opens in DevTools Performance/JavaScript Profiler). stop and analyze return a bottom-up list of expensive functions (self time) and a call tree of hot paths.

## Parameters

<ParamField body="tabId" type="integer">
  Target tab id from browser\_tabs, which lists tabs across all windows. Defaults to the agent's most recently opened usable tab, or the only usable tab. Otherwise select a listed tabId.
</ParamField>

<ParamField body="action" type="enum" required>
  One of: `start`, `stop`, `analyze`, `list`.
</ParamField>

<ParamField body="samplingIntervalUs" type="integer">
   
</ParamField>

<ParamField body="profileId" type="string">
   
</ParamField>

<ParamField body="limit" type="integer">
   
</ParamField>

## Example

```json theme={null}
{
  "tabId": 1234,
  "action": "start",
  "samplingIntervalUs": 500
}
```

```json theme={null}
{
  "tabId": 1234,
  "action": "stop",
  "limit": 20
}
```