Webcam test
Test your webcam in the browser: after one click the page shows a live preview with resolution, aspect ratio and measured frame rate, plus device switching and a mirror toggle. Nothing is recorded or uploaded.
Runs in your browserEvery computation happens in your browser — your data never leaves this device.
Webcam test
Press start and the browser asks for camera permission. Once granted you get a live preview with resolution, aspect ratio and measured frame rate. The stream stays local — nothing is recorded or uploaded.
Result
No test running yet. Press start and allow permission to see the preview and device parameters here.
The stream is only attached to a local <video> element: no recording, no snapshots, no uploads, and the tracks are stopped as soon as you press stop.
What this tool does
- Check a second-hand laptop or external webcam before buying: confirm the image works and that the resolution and frame rate match the listing.
- Run a pre-meeting sanity check to see whether another app is holding the camera or the image is cropped and badly tinted.
- Compare real parameters between the built-in camera, a USB webcam and a phone used as a webcam.
- Debug stutter: when the measured frame rate sits well below the reported one, the resolution is too high, the light is too dim or something else is eating bandwidth.
Example
Input
Start the test and allow permission; the device reports 1920×1080 at 30fps
Output
Resolution 1920 × 1080, aspect ratio 16:9, quality Full HD, 2.1 MP, reported frame rate 30 fps, measured frame rate 30.0 fps
The measured frame rate comes from requestAnimationFrame timestamps, so it only counts frames the page receives and is capped by the display refresh rate and background tab throttling.
Frequently asked questions
Why is the measured frame rate lower than the reported one?
It is derived from the browser paint callback, which is capped by the screen refresh rate (about 60fps on a 60Hz panel) and paused entirely in background tabs. Keep the page in the foreground and close GPU-heavy tabs to see the camera’s real ceiling.
The picture is reversed — is that expected?
Front-facing cameras are mirrored by default so the preview behaves like a mirror. The mirror toggle here turns that off and shows the raw orientation; it only affects display, never the video data.
Does the tool record or upload my video?
No. The stream is attached to a local video element only, the page sends no requests and writes no files, and pressing stop immediately halts the tracks so the camera light goes out.
The device list is empty — what should I do?
Browsers hide device labels before permission is granted, and some do not return any entries at all until then. Grant permission once and the list fills in; if it stays empty, the operating system has not detected a camera.
Keywords：webcam testcamera testvideo deviceframe rateresolution摄像头测试摄像头检测画面测试分辨率帧率