Browser Modes

B4n1Web offers three browser modes, each with different capabilities and resource usage.

Mode Comparison

Light Mode

Best for: Fast scraping, SEO content, static sites, APIs returning HTML.

browser = AgentBrowser()  # Default is Light
page = browser.goto("https://example.com")

What it does:

• Fetches HTML via HTTP
• Parses HTML to extract text, links, meta tags
• Converts to clean markdown
• No JavaScript execution

Use cases:

• Blog posts, articles, documentation
• Product listings, directories
• Any content rendered server-side

JS Mode

Best for: Sites that load content via JavaScript but don’t need screenshots.

from b4n1web import AgentBrowser, BrowserMode

browser = AgentBrowser(mode=BrowserMode.JS)
page = browser.goto("https://example.com")

What it does:

• Same as Light mode
• PLUS: Extracts data from JavaScript variables
• Can evaluate JavaScript expressions
• Returns page.js_output with JS results

Use cases:

• Single Page Applications (SPAs)
• Sites with JSON data embedded in scripts
• Dynamic content loaded via fetch/XHR

Render Mode

Best for: Screenshots, clicking, typing, waiting, full browser automation.

from b4n1web import AgentBrowser, BrowserMode

browser = AgentBrowser(mode=BrowserMode.RENDER)
page = browser.goto("https://example.com", wait_for=".content")

# Screenshot
screenshot_b64 = browser.screenshot(1920, 1080)

# Interact
browser.click(".button")
browser.type_text("#search", "query")
browser.wait_for_selector(".results", 5000)

What it does:

• Full Chromium browser (headless)
• Screenshots (full page or viewport)
• Click, type, hover, scroll
• Wait for selectors
• Full JavaScript execution
• All MCP tools available

Use cases:

• Visual regression testing
• Form automation
• Complex SPAs
• Screenshots for reports
• Any interaction requiring real browser

Choosing the Right Mode

START: Do you need screenshots or interaction (click/type/wait)?
  YES → RENDER MODE
  NO  → Does the site load content via JavaScript?
    YES → JS MODE
    NO  → LIGHT MODE

Mode Switching

# Change mode per request
browser = AgentBrowser(mode=BrowserMode.LIGHT)

# Light request
page = browser.goto("https://example.com")

# Switch to Render for screenshot
browser2 = AgentBrowser(mode=BrowserMode.RENDER)
page2 = browser2.goto("https://example.com")
screenshot = browser2.screenshot(1920, 1080)

Note: Each AgentBrowser instance has one mode. Create separate instances for different modes.

Performance Tips

Memory Comparison

Light:     ████░░░░░░░░░░░░░░░░░░░░  ~15 MB
JS:        ████░░░░░░░░░░░░░░░░░░░░  ~15 MB
Render:    ████████████░░░░░░░░░░░░  ~100 MB

Quick Reference