Limits & Billing

Billing model, rate limits, idle timeout, and known limitations

Billing

Browser API sessions are billed at 1 credit per 2 minutes, rounded up. A session that lasts 3 minutes costs 2 credits. A session that lasts 4 minutes 1 second also costs 2 credits (you're billed at the start of each 2-minute window).

Limits

Avoiding the idle timeout

The connection is closed if your script is silent for 120 seconds. Long workflow pauses (MFA wait, slow API polls, OAuth callbacks) need a keepalive — call any cheap browser API every ~60 seconds:

import asyncio

# during a long wait...
while waiting_for_mfa():
    await page.evaluate("() => 0")  # cheap keepalive
    await asyncio.sleep(60)

Playwright's page.wait_for_function() and page.wait_for_selector() also keep the session alive while they're polling — preferred for any "wait until X appears" loop.

The cleanest practice is browser.close() as soon as you're done — don't leave idle connections open just because you can.

Not supported

• Selenium / ChromeDriver — only CDP-native clients (Playwright, Puppeteer, chromedp) are supported.

Error responses

Browser API errors come back as standard HTTP responses before the WebSocket upgrade, so your CDP client receives them as connection failures: