browser-screenshots

name	browser-screenshots
description	Captures browser screenshots and videos on request using Playwright for embedding in tutorials. Use this when asked to capture, document, screenshot, or record a web page or locally running development server.

Browser Screenshot & Video Capture

Capture browser screenshots and record videos when the user requests them. This skill uses Playwright-based scripts to automate browser interactions and save screenshots or videos directly to disk.

When to Use

Use this skill when the user asks you to:

• Capture a screenshot of a specific URL
• Document a web page or web application state
• Take screenshots of a locally running development server
• Capture a sequence of browser interactions
• Record a video or GIF of a page with animations
• Create looping videos to showcase animated content

How to Capture

Use the Playwright capture script located at .github/skills/browser-screenshots/scripts/capture.cjs.

Basic Screenshot

node .github/skills/browser-screenshots/scripts/capture.cjs \
  --url https://example.com \
  --output static/screenshots/week-1/example-homepage.png

Common Options

Option	Description	Default
--url	URL to capture (required)	-
--output	Output file path (required)	-
--width	Viewport width	1280
--height	Viewport height	800
--fullpage	Capture full scrollable page	false
--element	CSS selector to capture specific element	-
--highlight	CSS selector to highlight with red border	-
--execute	JavaScript to run before capture	-
--wait	Milliseconds to wait before capture	500
--dark	Use dark color scheme	false
--phone	Use mobile phone viewport (375x812)	false

Examples

Capture with dark mode:

node .github/skills/browser-screenshots/scripts/capture.cjs \
  --url https://code.visualstudio.com \
  --dark \
  --output static/screenshots/week-1/vscode-homepage.png

Highlight a specific element:

node .github/skills/browser-screenshots/scripts/capture.cjs \
  --url https://github.com/new \
  --highlight ".repo-name-input" \
  --output static/screenshots/week-1/github-repo-name.png

Capture a specific element only:

node .github/skills/browser-screenshots/scripts/capture.cjs \
  --url https://example.com \
  --element ".hero-section" \
  --output static/screenshots/week-1/hero-only.png

Execute JavaScript before capture (e.g., click a button):

node .github/skills/browser-screenshots/scripts/capture.cjs \
  --url https://example.com \
  --execute "document.querySelector('button').click()" \
  --wait 1000 \
  --output static/screenshots/week-1/after-click.png

Full page screenshot:

node .github/skills/browser-screenshots/scripts/capture.cjs \
  --url https://example.com \
  --fullpage \
  --output static/screenshots/week-1/full-page.png

Saving Screenshots

Save to /static/screenshots/week-{week}/ with descriptive kebab-case filenames.

A WebP copy is automatically generated alongside each PNG/JPEG screenshot (requires cwebp — install with brew install webp). The Screenshot and PhoneScreenshot components serve WebP via <picture> elements for better performance. You do not need to reference the .webp files manually.

Naming convention: Use kebab-case:

• ✅ github-new-repo.png
• ✅ homepage-hero-section.png
• ❌ GitHubNewRepo.png

Directory structure:

static/screenshots/
  week-1/
    vscode-homepage.png
    github-new-repo.png
  week-2/
    ...

Embedding in Tutorials

When embedding in .svx files, use the Screenshot component:

<script>
  import Screenshot from '$lib/components/Screenshot.svelte';
</script>

<Screenshot
  src="/screenshots/week-1/github-new-repo.png"
  alt="GitHub new repository form"
  chromeTitle="Create a new repository"
  chromeUrl="https://github.com/new"
/>

Component Props

Prop	Type	Default	Description
src	string	required	Path relative to /static/
alt	string	required	Accessibility description
showChrome	boolean	true	Browser window styling
chromeTitle	string	''	Title bar text
chromeUrl	string	''	Address bar URL

Phone Screenshots

Use the --phone flag to capture at a mobile viewport size, then embed with the PhoneScreenshot component which wraps the image in a phone-shaped frame.

Capture

node .github/skills/browser-screenshots/scripts/capture.cjs \
  --url http://localhost:5174/ \
  --phone \
  --output static/screenshots/week-6/mobile-view.png

Embedding in Tutorials

<script>
  import PhoneScreenshot from '$lib/components/PhoneScreenshot.svelte';
</script>

<PhoneScreenshot
  src="/screenshots/week-6/mobile-view.png"
  alt="Mobile view of the page showing responsive layout"
/>

PhoneScreenshot Component Props

Prop	Type	Default	Description
src	string	required	Path relative to /static/
alt	string	required	Accessibility description
maxWidth	string	'320px'	CSS max-width of the phone frame

Recording Videos

Use the video recording script for pages with animations, GIFs, or dynamic content that needs to be captured over time.

Basic Video Recording

node .github/skills/browser-screenshots/scripts/record-video.cjs \
  --url https://example.com \
  --output static/screenshots/week-2/animation.gif \
  --duration 5

Video Recording Options

Option	Description	Default
--url	URL to capture (required)	-
--output	Output file path - .gif, .mp4, or .webm (required)	-
--width	Viewport width	1280
--height	Viewport height	800
--duration	Recording duration in seconds	5
--fps	Frames per second for GIF output	10
--execute	JavaScript to run before recording	-
--wait	Milliseconds to wait before recording	500
--dark	Use dark color scheme	false

Video Examples

Record a 5-second GIF:

node .github/skills/browser-screenshots/scripts/record-video.cjs \
  --url https://example.com \
  --output static/screenshots/week-2/demo.gif \
  --duration 5

Record MP4 video:

node .github/skills/browser-screenshots/scripts/record-video.cjs \
  --url https://example.com \
  --output static/videos/demo.mp4 \
  --duration 10

Higher framerate GIF for smoother animation:

node .github/skills/browser-screenshots/scripts/record-video.cjs \
  --url https://example.com \
  --output static/screenshots/week-2/smooth.gif \
  --fps 15 \
  --duration 3

Embedding Videos in Tutorials

For GIFs, use the same Screenshot component:

<Screenshot
  src="/screenshots/week-2/animation.gif"
  alt="Animated demo of the feature"
  chromeTitle="Demo"
  chromeUrl="https://example.com"
/>

For MP4 videos, use a standard HTML video tag in the .svx file:

<video autoplay loop muted playsinline width="100%">
  <source src="/videos/demo.mp4" type="video/mp4" />
</video>

Authenticated Sessions

Some pages require login to display certain elements (e.g., the "Use this template" button on GitHub). You can save authenticated sessions and reuse them for captures.

Saving a Session

Run the session saver script, which opens a browser where you can log in:

node .github/skills/browser-screenshots/scripts/save-session.cjs \
  --url https://github.com \
  --session github

This opens a browser window. Log in to the site, then press Enter in the terminal to save your session. Sessions are stored in ~/.playwright-sessions/.

Using a Saved Session

Add the --session flag to capture or record commands:

# Screenshot with GitHub session
node .github/skills/browser-screenshots/scripts/capture.cjs \
  --url https://github.com/palewire/cuny-jour-static-site-template \
  --session github \
  --output static/screenshots/week-2/github-repo.png

# Video with GitHub session
node .github/skills/browser-screenshots/scripts/record-video.cjs \
  --url https://github.com/settings \
  --session github \
  --output static/screenshots/week-2/github-settings.gif

Listing Saved Sessions

node .github/skills/browser-screenshots/scripts/save-session.cjs --list

Session Options

Option	Description	Default
--url	URL to open for login	https://github.com
--session	Name to save session as	default
--list	List all saved sessions	-

Prerequisites

Playwright must be installed. If not already installed:

npm install playwright
npx playwright install chromium

For GIF output, ffmpeg must also be installed:

brew install ffmpeg

Limitations

• Cannot capture: VS Code windows, terminal output, system dialogs (these require manual screenshots)
• Requires network access: URLs must be reachable from the machine running the script
• GIF output requires ffmpeg: Install via brew install ffmpeg on macOS
• Sessions expire: Saved sessions will expire based on the site's cookie policies; re-run save-session when needed