Kernel: a cloud browser an agent can create, drive, and replay

Measured 2026-10-08 from this machine (Chromium vs Kernel us-east). Real API run, not a mock.

1. Agent creates a browser and drives it

const kb = await kernel.browsers.create();            // ~0.6s round trip
// kb.session_id, kb.cdp_ws_url, kb.browser_live_view_url
await kernel.browsers.replays.start(kb.session_id);
await kernel.browsers.playwright.execute(kb.session_id, { code: `
  await page.goto('https://en.wikipedia.org/wiki/Main_Page');
  await page.fill('input[name=search]', 'headless browser');
  await page.keyboard.press('Enter');
  await page.goto('https://news.ycombinator.com');
  return await page.title();` });
await kernel.browsers.replays.stop(replayId, { id_or_name: kb.session_id });
await kernel.browsers.deleteByID(kb.session_id);

2. What you get back: the recorded session (real MP4 from that run)

3. Faster than local Chrome? Depends on where the commands run

Median ms	Local Chrome	Kernel via CDP	Kernel execute (in VM)
Wikipedia load	190	262	114
Hacker News load	279	256	110
example.com load	37	166	18
20 small commands	69	3133	228
Start browser	402	600–671	—

Takeaway: the Kernel VM loads real sites faster (datacenter network), but every command sent from your machine costs ~157 ms. Send the whole script to playwright.execute instead. Single run, 3 samples per page, one region.