humanlayer The chrome-devtools-mcp CLI lets you interact with the browser from your terminal.
Setup
Note: If this is your very first time using the CLI, see references/installation.md for setup. Installation is a one-time prerequisite and is not part of the regular AI workflow.
AI Workflow
- Execute: Run tools directly (e.g.,
chrome-devtools list_pages). The background server starts implicitly; do not runstart/status/stopbefore each use. - Inspect: Use
take_snapshotto get an element<uid>. - Act: Use
click,fill, etc. State persists across commands.
Snapshot example:
uid=1_0 RootWebArea "Example Domain" url="https://example.com/"
uid=1_1 heading "Example Domain" level="1"
Command Usage
chrome-devtools <tool> [arguments] [flags]
Use --help on any command. Output defaults to Markdown, use --output-format=json for JSON.
Input Automation ( from snapshot)
chrome-devtools take_snapshot --help # Help message for commands, works for any command.
chrome-devtools take_snapshot # Take a text snapshot of the page to get UIDs for elements
chrome-devtools click "id" # Clicks on the provided element
chrome-devtools click "id" --dblClick true --includeSnapshot true # Double clicks and returns a snapshot
chrome-devtools drag "src" "dst" # Drag an element onto another element
chrome-devtools drag "src" "dst" --includeSnapshot true # Drag an element and return a snapshot
chrome-devtools fill "id" "text" # Type text into an input or select an option
chrome-devtools fill "id" "text" --includeSnapshot true # Fill an element and return a snapshot
chrome-devtools handle_dialog accept # Handle a browser dialog
chrome-devtools handle_dialog dismiss --promptText "hi" # Dismiss a dialog with prompt text
chrome-devtools hover "id" # Hover over the provided element
chrome-devtools hover "id" --includeSnapshot true # Hover over an element and return a snapshot
chrome-devtools press_key "Enter" # Press a key or key combination
chrome-devtools press_key "Control+A" --includeSnapshot true # Press a key and return a snapshot
chrome-devtools type_text "hello" # Type text using keyboard into a focused input
chrome-devtools type_text "hello" --submitKey "Enter" # Type text and press a submit key
chrome-devtools upload_file "id" "file.txt" # Upload a file through a provided element
chrome-devtools upload_file "id" "file.txt" --includeSnapshot true # Upload a file and return a snapshot
Navigation
chrome-devtools close_page 1 # Closes the page by its index
chrome-devtools list_pages # Get a list of pages open in the browser
chrome-devtools navigate_page --url "https://example.com" # Navigates the currently selected page to a URL
chrome-devtools navigate_page --type "reload" --ignoreCache true # Reload page ignoring cache
chrome-devtools navigate_page --url "https://example.com" --timeout 5000 # Navigate with a timeout
chrome-devtools navigate_page --handleBeforeUnload "accept" # Handle before unload dialog
chrome-devtools navigate_page --type "back" --initScript "foo()" # Navigate back and run an init script
chrome-devtools new_page "https://example.com" # Creates a new page
chrome-devtools new_page "https://example.com" --background true --timeout 5000 # Create new page in background
chrome-devtools new_page "https://example.com" --isolatedContext "ctx" # Create new page with isolated context
chrome-devtools select_page 1 # Select a page as a context for future tool calls
chrome-devtools select_page 1 --bringToFront true # Select a page and bring it to front
Emulation
chrome-devtools emulate --networkConditions "Offline" # Emulate network conditions
chrome-devtools emulate --cpuThrottlingRate 4 --geolocation "0,0" # Emulate CPU throttling and geolocation
chrome-devtools emulate --colorScheme "dark" --viewport "1920x1080" # Emulate color scheme and viewport
chrome-devtools emulate --userAgent "Mozilla/5.0..." # Emulate user agent
chrome-devtools resize_page 1920 1080 # Resizes the selected page's window
Performance
chrome-devtools performance_analyze_insight "1" "LCPBreakdown" # Get more details on a specific Performance Insight
chrome-devtools performance_start_trace true false # Starts a performance trace recording
chrome-devtools performance_start_trace true true --filePath t.gz # Start trace and save to a file
chrome-devtools performance_stop_trace # Stops the active performance trace
chrome-devtools performance_stop_trace --filePath "t.json" # Stop trace and save to a file
chrome-devtools take_memory_snapshot "./snap.heapsnapshot" # Capture a memory heapsnapshot
Network
chrome-devtools get_network_request # Get the currently selected network request
chrome-devtools get_network_request --reqid 1 --requestFilePath req.md # Get request by id and save to file
chrome-devtools get_network_request --responseFilePath res.md # Save response body to file
chrome-devtools list_network_requests # List all network requests
chrome-devtools list_network_requests --pageSize 50 --pageIdx 0 # List network requests with pagination
chrome-devtools list_network_requests --resourceTypes Fetch # Filter requests by resource type
chrome-devtools list_network_requests --includePreservedRequests true # Include preserved requests
Debugging & Inspection
chrome-devtools evaluate_script "() => document.title" # Evaluate a JavaScript function on the page
evaluate_script "(a) => a.innerText" --args 1_4 # Evaluate JS with UID arguments
chrome-devtools get_console_message 1 # Gets a console message by its ID
chrome-devtools lighthouse_audit --mode "navigation" # Run Lighthouse audit for navigation
chrome-devtools lighthouse_audit --mode "snapshot" --device "mobile" # Run Lighthouse audit for a snapshot on mobile
chrome-devtools lighthouse_audit --outputDirPath ./out # Run Lighthouse audit and save reports
chrome-devtools list_console_messages # List all console messages
chrome-devtools list_console_messages --pageSize 20 --pageIdx 1 # List console messages with pagination
chrome-devtools list_console_messages --types error --types info # Filter console messages by type
chrome-devtools list_console_messages --includePreservedMessages true # Include preserved messages
chrome-devtools take_screenshot # Take a screenshot of the page viewport
chrome-devtools take_screenshot --fullPage true --format "jpeg" --quality 80 # Take a full page screenshot as JPEG with quality
chrome-devtools take_screenshot --uid "id" --filePath "s.png" # Take a screenshot of an element
chrome-devtools take_snapshot # Take a text snapshot of the page from the a11y tree
chrome-devtools take_snapshot --verbose true --filePath "s.txt" # Take a verbose snapshot and save to file
Service Management
chrome-devtools start # Start or restart chrome-devtools-mcp
chrome-devtools status # Checks if chrome-devtools-mcp is running
chrome-devtools stop # Stop chrome-devtools-mcp if any