Connect to a Chrome instance via WebSocket URL. Get the URL from http://localhost:PORT/json/version or from an existing cdp-tools connection.

List available Chrome debugging targets. Use this to find the WebSocket URL to connect to.

Disconnect from Chrome

Enable request interception. Optionally specify URL patterns to intercept.

Disable request interception

Continue a paused request, optionally modifying URL, method, headers, or body

Respond to a paused request with a custom/mock response

Fail a paused request with an error

Get the response body of a paused request (at Response stage)

List all currently paused/intercepted requests

Emulate a specific device (iPhone, Pixel, iPad, etc.) with correct viewport, DPR, user agent, and touch

Set custom device metrics (viewport size, scale, mobile mode)

Fake the browser's geolocation to any coordinates

Override the browser's timezone

Override the browser's locale for i18n testing

Override the browser's user agent string

Toggle dark mode (prefers-color-scheme)

Toggle reduced motion preference

Simulate vision deficiencies (color blindness, blurred vision)

Throttle CPU to simulate slower devices

Toggle touch emulation

Clear all emulation overrides and reset to defaults

List all available device presets for emulation

Run an accessibility audit on the current page. Checks for missing alt text, unlabeled buttons/links, form inputs without labels, empty headings, and clickable elements without roles.

Get the accessibility tree for the current page (what screen readers see)

Search the accessibility tree by role and/or accessible name

Get current runtime performance metrics (DOM nodes, event listeners, layout counts, JS heap, etc.)

Get Core Web Vitals (LCP, CLS, FCP, TTFB) with GOOD/NEEDS IMPROVEMENT/POOR ratings

Start CPU profiling. Perform the actions you want to profile, then call perf_cpu_profile_stop.

Stop CPU profiling and get the results with top functions by CPU time

Take a heap memory snapshot to find memory leaks

Get computed CSS styles for an element. Optionally filter to specific properties.

Get all CSS rules matching an element (inline, matched, inherited, pseudo-elements)

Get background colors and font info for an element (useful for contrast checking)

Force pseudo-states on an element (e.g. :hover, :focus, :active) for testing

Get the actual fonts used to render an element (not just font-family, the actual loaded fonts)

List all media queries used across all stylesheets

Start tracking CSS rule usage. Browse around, then call css_coverage_stop to see which rules are unused.

Stop CSS coverage tracking and get the report showing used vs unused rules

Set a CSS property value on an element (live modification)