> ## 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_coverage

> Coverage panel.

Coverage panel. start records JavaScript and CSS usage; stop reports per-file used/unused bytes; detail lists the unused ranges of one file with line numbers and snippets.

## 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`, `detail`.
</ParamField>

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

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

<ParamField body="reload" type="boolean">
  start: reload after enabling so every function is instrumented (default true, like the DevTools Coverage panel)
</ParamField>

## Example

```json theme={null}
{
  "tabId": 1234,
  "action": "start",
  "reload": true
}
```

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

```json theme={null}
{
  "tabId": 1234,
  "action": "detail",
  "url": "https://example.com/app.js"
}
```