Chrome Devtools CLI

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

1. Execute: Run tools directly. If you don't know the target page's ID, run chrome-devtools list_pages to find it. The background server starts implicitly; do not run start/status/stop before each use.
2. Inspect: Use chrome-devtools take_snapshot <pageId> to get an element <uid>.
3. Act: Use chrome-devtools click <pageId> <uid>, chrome-devtools fill <pageId> <uid> <value>, 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"

Permissions & File Access

By default, the CLI has full filesystem access (--allowUnrestrictedPaths=true), allowing file-saving parameters (--filePath, --outputDirPath) and upload_file to access files anywhere on the system. Pass --allowUnrestrictedPaths=false if you want to restrict file access to the OS temp directory.

Command Usage

chrome-devtools <tool> [arguments] [flags]

• Required arguments are passed positionally; optional arguments use flags.
• Use --help on any command for usage details.
• Output defaults to plain Markdown-like text; pass --output-format=json for JSON.

Input Automation (<uid> from snapshot)

chrome-devtools take_snapshot 1 # Take a text snapshot of the page to get UIDs for elements
chrome-devtools click 1 "id" # Clicks on the provided element
chrome-devtools click 1 "id" --dblClick true --includeSnapshot true # Double clicks and returns a snapshot
chrome-devtools drag 1 "src" "dst" # Drag an element onto another element
chrome-devtools drag 1 "src" "dst" --includeSnapshot true # Drag an element and return a snapshot
chrome-devtools fill 1 "id" "text" # Type text into an input, textarea, or select an option
chrome-devtools fill 1 "id" "text" --includeSnapshot true # Fill an element and return a snapshot
chrome-devtools handle_dialog 1 accept # Handle a browser dialog (accept/dismiss)
chrome-devtools handle_dialog 1 dismiss --promptText "hi" # Dismiss a dialog with prompt text
chrome-devtools hover 1 "id" # Hover over the provided element
chrome-devtools hover 1 "id" --includeSnapshot true # Hover over an element and return a snapshot
chrome-devtools press_key 1 "Enter" # Press a key or key combination ("Control+A", "Escape")
chrome-devtools press_key 1 "Control+A" --includeSnapshot true # Press a key and return a snapshot
chrome-devtools type_text 1 "hello" # Type text using keyboard into a focused input
chrome-devtools type_text 1 "hello" --submitKey "Enter" # Type text and press a submit key
chrome-devtools upload_file 1 "id" "file.txt" # Upload a file through a provided element
chrome-devtools upload_file 1 "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 1 --url "https://example.com" # Navigates the currently selected page to a URL
chrome-devtools navigate_page 1 --type "reload" --ignoreCache true # Reload page ignoring cache
chrome-devtools navigate_page 1 --url "https://example.com" --timeout 5000 # Navigate with a timeout
chrome-devtools navigate_page 1 --handleBeforeUnload "accept" # Handle before unload dialog
chrome-devtools navigate_page 1 --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 1 --networkConditions "Offline" # Emulate network conditions
chrome-devtools emulate 1 --cpuThrottlingRate 4 --geolocation "0x0" # Emulate CPU throttling and geolocation
chrome-devtools emulate 1 --colorScheme "dark" --viewport "1920x1080" # Emulate color scheme and viewport
chrome-devtools emulate 1 --userAgent "Mozilla/5.0..." # Emulate user agent
chrome-devtools resize_page 1 1920 1080 # Resizes the selected page's window

Performance

chrome-devtools performance_analyze_insight 1 "1" "LCPBreakdown" # Get more details on a specific Performance Insight (pageId, insightSetId, insightName)
chrome-devtools performance_start_trace 1 --reload true --autoStop false # Starts a performance trace recording (reload, autoStop)
chrome-devtools performance_start_trace 1 --reload true --autoStop true --filePath "t.json.gz" # Start trace and save to a file
chrome-devtools performance_stop_trace 1 # Stops the active performance trace
chrome-devtools performance_stop_trace 1 --filePath "t.json.gz" # Stop trace and save to a file

Memory

chrome-devtools take_heapsnapshot 1 "./snap.heapsnapshot" # Capture a memory heap snapshot

Memory Debugging (requires --memoryDebugging=true)

chrome-devtools get_heapsnapshot_summary "./snap.heapsnapshot" # Get snapshot summary stats
chrome-devtools compare_heapsnapshots "./base.heapsnapshot" "./target.heapsnapshot" # Compare two snapshots
chrome-devtools get_heapsnapshot_class_nodes "./snap.heapsnapshot" "Array" # Inspect class instances
chrome-devtools get_heapsnapshot_details "./snap.heapsnapshot" 123 # Detailed object properties
chrome-devtools get_heapsnapshot_dominators "./snap.heapsnapshot" 123 # Dominator tree for node
chrome-devtools get_heapsnapshot_duplicate_strings "./snap.heapsnapshot" # Find duplicated strings
chrome-devtools get_heapsnapshot_edges "./snap.heapsnapshot" 123 # Node edges/references
chrome-devtools get_heapsnapshot_object_details "./snap.heapsnapshot" 123 # Object details by node ID
chrome-devtools get_heapsnapshot_retainers "./snap.heapsnapshot" 123 # Retaining objects
chrome-devtools get_heapsnapshot_retaining_paths "./snap.heapsnapshot" 123 # Shortest retaining paths
chrome-devtools close_heapsnapshot "./snap.heapsnapshot" # Free memory from loaded snapshot

Network

chrome-devtools get_network_request 1 # Get the currently selected network request for page 1
chrome-devtools get_network_request 1 --reqid 1 --requestFilePath "req.md" # Get request by id and save to file
chrome-devtools get_network_request 1 --responseFilePath "res.md" # Save response body to file
chrome-devtools list_network_requests 1 # List all network requests for page 1
chrome-devtools list_network_requests 1 --pageSize 50 --pageIdx 0 # List network requests with pagination
chrome-devtools list_network_requests 1 --resourceTypes Fetch # Filter requests by resource type
chrome-devtools list_network_requests 1 --includePreservedRequests true # Include preserved requests

Debugging & Inspection

chrome-devtools evaluate_script "() => document.title" --pageId 1 # Evaluate a JavaScript function on page 1
chrome-devtools evaluate_script "(a) => a.innerText" --pageId 1 --args 1_4 # Evaluate JS with UID arguments on page 1
chrome-devtools get_console_message 1 1 # Gets a console message by its ID
chrome-devtools get_css_styles 1 "1_4" # Retrieves resolved CSS styles (inline, matched, inherited, pseudo) for an element on page 1
chrome-devtools get_css_styles 1 "1_4" --pageSize 20 --pageIdx 0 # Get CSS styles with pagination on page 1
chrome-devtools lighthouse_audit 1 --mode "navigation" # Run Lighthouse audit for navigation