chrome-capture

Record a Chrome tab at 60-120fps (up to 2160p) straight to a AV1 .mp4. Tab audio too. No ffmpeg.

npx chrome-capture https://paulirish.github.io/chrome-capture/ demo.mp4 4s

Chrome 153+ has a native MP4 tab recorder! 😻

For the past ~decade, Page.startScreencast was the only way to get video frames out of CDP. That API is from ~2013, built so DevTools could show a live preview of a USB-tethered Android. (So good!) Both Playwright (recordVideo) and Puppeteer (page.screencast()) built their video capture on top of it: Chrome JPEG-encodes each frame, base64s it into JSON over CDP, waits for an ack, and the library pipes those JPEGs into ffmpeg. It's served us well.

In Sept 2026… the new Page.startScreenRecording landed (thx alex rudenko!). Frames go straight from the compositor to an out-of-process encoder over shared memory, and Chrome writes AV1 into the mp4 as it goes (plus optional tab audio). 💅 Stopping is ~instant because the encoding is already done (no multi-second ffmpeg flush at the end). And you can start/stop recording whenever you want: log in, warm up the page, then record just the interaction.

In short: It's hot. It's good. really good.

senna-800kg-1920x1080-120fps.mp4

(Thx github.com/Sam1983Aing/senna-800kg for this Gemini Argon generation.)

Puppeteer v25.10+ wraps this in an experimental page.record() (deprecating page.screencast()). (Update: Nov 10th... Playwright now has an open PR (#43999) bringing Page.startScreenRecording to Chromium! :fingers_crossed:)

Feel free to install this from npm.. or tbh just point your agent at src/index.ts and steal the implementation. It's tiny.

CLI

# 720p @ 60fps for 4s, with tab audio
npx chrome-capture https://paulirish.github.io/chrome-capture/ demo.mp4 4s

# 1080p @ 120fps (needs a 120Hz display and headful Chrome, e.g. a ProMotion MacBook)
npx chrome-capture https://paulirish.github.io/chrome-capture/ 120fps.mp4 5s --fps=120 --width=1920 --height=1080 --headful

# Record the page with DevTools open next to it
npx chrome-capture https://paulirish.github.io/chrome-capture/ devtools.mp4 5s --with-devtools

The CLI records audio by default and runs headless (--headless=new) for <= 60fps, automatically switching to --headful on macOS when --fps > 60 so Chrome can lock onto ProMotion's 120Hz CVDisplayLink. --help for the rest.

Playwright, Puppeteer, or raw CDP

startRecording() takes a Playwright Page, a Puppeteer Page, or a CDP session. It defaults to 60fps and works with await using, so the mp4 is written when the block exits:

import {startRecording} from 'chrome-capture';

// `page` can be a Playwright Page, a Puppeteer Page, or a CDP session!!
{
  await using rec = await startRecording(page, {
    outputPath: 'flow.mp4',   // optional: omit to get a Buffer from rec.stop()
    frameRate: 60,            // default: 60 (up to 120 on a 120Hz display)
    maxWidth: 1280,           // default: 1280
    maxHeight: 720,           // default: 720
    captureArea: 'target',    // 'target' (viewport) or 'browserWindow'
    audio: false,             // 48kHz stereo Opus tab audio
  });
  await page.goto('https://paulirish.github.io/chrome-capture/');
  await page.click('a');
}

@playwright/test fixture

Records every test and attaches the mp4 to the report:

import {test as base} from '@playwright/test';
import {screenRecordingFixture} from 'chrome-capture/playwright';

export const test = base.extend({
  recordVideo60fps: screenRecordingFixture({auto: true, audio: true}),
});

(Drop auto: true if you'd rather call recordVideo60fps.start() yourself, mid-test.)

Raw CDP

import {CdpScreenRecorder, connectCdpSession} from 'chrome-capture';

const session = await connectCdpSession(pageWebSocketDebuggerUrl);
const recorder = new CdpScreenRecorder(session);

await recorder.start({maxWidth: 1920, maxHeight: 1080});
// ... do stuff
const mp4 = await recorder.stop();
session.close();

Visible cursor

With Playwright, await page.screencast.showActions() draws its cursor, element highlights, and click badges right into the DOM (without starting Page.startScreencast), so startRecording(page) captures them natively. To restyle the cursor SVG and click ring yourself, inject a custom DOM overlay instead: see examples/custom-cursor/ (pointermove/pointerdown tracking for Playwright or manual sessions) and examples/raw-cdp-cursor/ (raw CDP Bezier choreography).

Benchmarks

Same 6.4s UI replay (typing, clicks, drag-and-drop, scroll) at 1280x800, comparing the Page.startScreencast + ffmpeg pipeline (recordVideo) against Page.startScreenRecording (chrome-capture at its default 60fps) on an M4 Max. Methodology and the full numbers are in benchmarks/README.md.

	recordVideo (startScreencast)	chrome-capture (startScreenRecording)
Output fps	25 (up to 60)	60 (up to 120)
Total wall-clock	21s	11s
Stop + finalize	3,800ms	17ms
WebSocket traffic	10.5 MB	450 KB
Final file size	480 KB	330 KB
PSNR vs. lossless screenshot	32 dB	34 dB
Audio	none	optional

Because Chrome encodes the video in-flight instead of piping JPEGs to ffmpeg, stopping takes 17ms instead of 3.8s (or 91ms vs 20.5s at 2160p), and the whole test finishes ~10s quicker.

What about bitrate and visual quality? There's no bitrate/CRF knob (yet). Under the hood, Chrome encodes on the fly with libaom AV1 in realtime 1-pass VBR and scales target bitrate linearly with pixel rate (2 Mbps at 720p30 -> 9 Mbps at 1080p60 -> 18 Mbps at 1080p120 -> 72 Mbps at 2160p120).

The high bitrate sweet spot is 1080p60 (9 Mbps) and up (bumping resolution or frameRate doubles as a backdoor bitrate multiplier). If you ever need lossless 1px text fidelity and only care about ~10-15fps, an offline Page.startScreencast({format: 'png'}) -> ffmpeg pipeline still has a place.

How high can it go?

Video files can lie about fps. So the stress test (demo) draws a binary frame counter on every requestAnimationFrame, then decodes it back out of the mp4 to count unique frames:

barcode-1920x1080-120fps.mp4

• Mac (--headless=new): 2160p @ 60fps (60 unique fps). Headless Chrome still gets full Metal GPU acceleration, so 1080p, 1440p, and 2160p all lock at 60fps, but headless drives rAF from a synthetic 60Hz timer instead of the display's CVDisplayLink.
• Mac (--headful on 120Hz ProMotion): 1080p @ 120fps and 2160p @ 120fps 😲 (119.9 fps, 59.8 Mbps AV1 + stereo Opus on Three.js/WebGL2 scenes in examples/capture-demos.ts).
• Headless Linux (no GPU / CI): 1080p @ 60fps (60.4 unique fps) or 1440p @ 60fps (~58 unique fps) on standard 60Hz vsync, and up to 1080p @ 75-83fps if you uncap vsync (--disable-frame-rate-limit --disable-gpu-vsync).
• Other setups (Windows / Linux w/ discrete GPU): ?

One macOS gotcha: don't pass --disable-frame-rate-limit --disable-gpu-vsync on a GPU-accelerated Mac. rAF spins at 1,600-9,800fps, floods the Metal command queue, and starves the capture readback (dropping 2160p@60 to 0.3fps). Leave native vsync alone; it's what gets you to 120.

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