Browser Automation with Chrome DevTools Protocol

Control Chrome browser programmatically using simple command-line scripts. All scripts auto-start Chrome in headless mode if not running.

Available Commands

All scripts are in bin/:

screenshot - Capture web pages as images

bin/screenshot URL [OUTPUT] [OPTIONS]

Options:

• --full-page - Capture entire scrollable page
• --selector=CSS - Capture specific element
• --format=png|jpeg|webp - Output format (default: png)
• --quality=N - JPEG/WebP quality 0-100
• --width=N --height=N - Set viewport size
• --max-dimension=N - Max output dimension (default: 8000, auto-scales large pages)

Examples:

# Basic screenshot
bin/screenshot https://example.com /tmp/page.png

# Full page as JPEG
bin/screenshot https://example.com /tmp/full.jpg --full-page --format=jpeg

# Capture specific element
bin/screenshot https://example.com /tmp/header.png --selector="header"

pdf - Generate PDFs from web pages

bin/pdf URL [OUTPUT] [OPTIONS]

Options:

• --paper=letter|a4|legal|a3|a5|tabloid - Paper size (default: letter)
• --landscape - Landscape orientation
• --margin=INCHES - All margins (default: 0.4)
• --scale=FACTOR - Scale 0.1-2.0 (default: 1.0)
• --no-background - Skip background colors/images

Examples:

# Basic PDF
bin/pdf https://example.com /tmp/doc.pdf

# A4 landscape
bin/pdf https://example.com /tmp/report.pdf --paper=a4 --landscape

# Tight margins
bin/pdf https://example.com /tmp/compact.pdf --margin=0.25

extract - Extract content from web pages

bin/extract URL [OPTIONS]

Options:

• --format=markdown|text|html - Output format (default: markdown)
• --selector=CSS - Extract specific element only
• --links - Also list all links
• --images - Also list all images
• --metadata - Also show page metadata

Examples:

# Get page as markdown
bin/extract https://example.com

# Get plain text from article
bin/extract https://example.com --format=text --selector="article"

# Get all links and metadata
bin/extract https://example.com --links --metadata

navigate - Navigate and interact with pages

bin/navigate URL [OPTIONS]

Options:

• --wait-for=SELECTOR - Wait for element to appear
• --click=SELECTOR - Click an element
• --type=SELECTOR=TEXT - Type text into input field
• --eval=JAVASCRIPT - Execute JavaScript and print result
• --timeout=SECONDS - Timeout (default: 30)

Examples:

# Navigate and wait for content
bin/navigate https://example.com --wait-for="#content"

# Fill form and submit
bin/navigate https://google.com --type="input[name=q]=hello" --click="input[type=submit]"

# Get page title via JavaScript
bin/navigate https://example.com --eval="document.title"

form - Fill out and submit web forms

bin/form URL [OPTIONS]

Options:

• --fill=SELECTOR=VALUE - Fill input field (can repeat)
• --select=SELECTOR=VALUE - Select dropdown option (can repeat)
• --fill-json='{"sel":"val"}' - Fill multiple fields from JSON
• --submit=SELECTOR - Click submit button after filling
• --wait-for=SELECTOR - Wait for element before filling
• --wait-after=SELECTOR - Wait for element after submit
• --screenshot=PATH - Take screenshot after completion

Examples:

# Login form
bin/form https://example.com/login \
  --fill='#username=john' \
  --fill='#password=secret' \
  --submit='button[type=submit]'

# Form with dropdowns
bin/form https://example.com/register \
  --fill='#name=John Doe' \
  --fill='#email=john@example.com' \
  --select='#country=US' \
  --submit='#register-btn'

# Using JSON
bin/form https://example.com/contact \
  --fill-json='{"#name":"John","#email":"john@test.com"}' \
  --submit='button.send'

record - Record screencast frames

bin/record URL OUTPUT_DIR [OPTIONS]

Options:

• --duration=SECONDS - Recording duration (default: 5)
• --count=N - Exact number of frames to capture
• --format=jpeg|png - Frame format (default: jpeg)
• --quality=N - JPEG quality 0-100 (default: 80)
• --max-width=N - Maximum frame width
• --max-height=N - Maximum frame height
• --fps=N - Approximate frames per second (default: 10)

Examples:

# Record 5 seconds
bin/record https://example.com /tmp/frames

# Record 30 PNG frames
bin/record https://example.com /tmp/frames --count=30 --format=png

# Convert to video with ffmpeg
ffmpeg -framerate 10 -i /tmp/frames/frame-%04d.jpg -c:v libx264 output.mp4

chrome-status - Check browser status

bin/chrome-status

Shows whether Chrome is running, version info, and open tabs.

Common Workflows

Screenshot a page

bin/screenshot https://example.com /tmp/screenshot.png

Convert page to PDF

bin/pdf https://example.com /tmp/document.pdf --paper=a4

Scrape page content

bin/extract https://example.com --format=markdown

Fill and submit a form

bin/form https://example.com/login \
  --fill='#username=user' \
  --fill='#password=pass' \
  --submit='button[type=submit]' \
  --wait-after='.dashboard'

Record a screencast

bin/record https://example.com /tmp/frames --duration=10
ffmpeg -framerate 10 -i /tmp/frames/frame-%04d.jpg -c:v libx264 video.mp4

Notes

• Chrome auto-starts in headless mode when needed
• Chrome continues running between commands for speed
• Use pkill -f 'chrome.*--remote-debugging-port' to stop Chrome manually
• Default port is 9222; set CHROME_DRIVER_PORT to change
• All scripts support --help for full usage info
• Large screenshots are auto-scaled to fit within 8000px (API limit)