How to Test Your Webcam and FPS Online
A good webcam test answers three questions: does the camera work, what resolution is it really sending, and how many frames per second actually arrive. Spec sheets and driver dialogs report what a camera can do; CamTestKit measures what it is doing right now, in your browser, with your lighting and USB port.
- Close other video apps. Zoom, Teams, Discord, OBS and other browser tabs can lock the camera or force it into a lower mode.
- Press “Test my webcam” and allow access. The page requests the highest resolution your camera supports. Nothing is uploaded.
- Pick your camera under Camera & mode, below the picture, if you have several (laptop camera, USB webcam, virtual camera, capture card).
- Wait three seconds for the FPS counter to stabilize, then read the diagnostics result.
- Take a snapshot to inspect sharpness at full native resolution — the PNG is not scaled to your screen.
Reading the metrics
| Metric | What it means | Healthy value |
|---|---|---|
| Stream resolution | Pixel size of frames the camera actually delivers (not the size of the preview box). | 1920×1080 or higher |
| Measured FPS | New frames received per second, counted frame by frame. | 29–30 or 59–60 |
| Frame interval / jitter | Average time between frames and how much it varies. | 33.3 ms, with no frames arriving half a frame late (a few ms of variation is normal) |
| Requested FPS | The frame rate the driver reports it is configured for. | Matches measured FPS |
| Color space | Primaries / transfer function of decoded frames (where supported). | BT.709 or sRGB |
Why measured FPS beats advertised FPS
Browsers expose a frameRate setting on every camera track, but it is only the configured target. CamTestKit uses
requestVideoFrameCallback to count every decoded frame as it arrives, including frames that arrive between screen refreshes, and averages the
count over one-second windows. Frames that arrive half a frame late or more tell you whether motion will look smooth or stuttery on a call; a few milliseconds of variation is normal and invisible.
Fixing Common Webcam Problems
Low frame rate (15 fps instead of 30)
There are three causes, and the test tells you which one you have. The camera may have no 30 fps mode at all, so light will not help. It may be set to a slower mode, which you can change under Camera & mode. Or, most often, the room is too dim: auto-exposure lengthens each frame beyond 33 ms, so add a light in front of you, turn off “low-light compensation” in the camera software, or choose a lower resolution. A USB 2.0 hub shared with other devices can also cap the frame rate.
Resolution stuck at 720p or 640×480
Plug the camera straight into a USB 3 port, close other apps that may hold the camera in a low mode, and select the physical camera rather than a virtual one (OBS, Snap Camera, NVIDIA Broadcast) in the device list. If the largest mode listed under Camera type (in All measurements) is below 1920×1080, the camera itself is the limit.
Rolling bands or pulsing brightness
That is mains flicker from your room lights. Set the camera’s anti-flicker (powerline frequency) to 50 Hz or 60 Hz to match your country, or use the flicker test to find a flicker-safe shutter speed.
Video feels delayed on calls
Delay from camera to screen under 100 ms feels instant; above 250 ms is noticeable. Higher frame rates and fewer software filters reduce latency.
Benchmark Any Camera with Test Patterns
Want to go beyond your webcam? The test pattern generator turns your monitor into a precision target for phones, DSLRs, mirrorless and action cameras: rolling shutter, shutter speed, resolution, focus and white balance.
Webcam Test FAQ
Is this webcam test private? Is my video uploaded?
Your video never leaves your device. CamTestKit runs entirely in your browser using the WebRTC getUserMedia API. Frames are analyzed locally, snapshots are generated locally, and there is no server that receives video or images.
Why does my webcam only show 15 fps instead of 30 fps?
The most common cause is low light. Most webcams use automatic exposure, and when the room is dark they lengthen each exposure beyond 33 ms, which forces the frame rate down to 15 fps or lower. Add a front-facing light, disable low-light compensation in the camera software, or lower the resolution. USB 2.0 hubs and other apps using the camera can also reduce the frame rate.
Why is my 1080p webcam only running at 720p or 640x480 in the browser?
Browsers pick a default mode unless a page asks for more. CamTestKit requests the highest resolution your camera offers, so if you still see 720p the limit is usually the camera itself, a USB 2.0 port or hub without enough bandwidth, or a virtual camera driver sitting in between. Select the camera directly in the device list and try another USB port.
How accurate is the FPS counter?
In Chrome, Edge and Safari the counter uses requestVideoFrameCallback, which fires for every new decoded camera frame and reports how many frames were presented, so the result reflects frames actually delivered rather than the advertised setting. Values are averaged over one-second windows. Browsers without that API use a requestAnimationFrame fallback, which is marked as estimated.
Why does my camera not appear in the device list?
Browsers hide camera names until you grant permission, so press Test my webcam first and the list will fill in. If a camera is still missing, make sure it is connected, not disabled by a privacy switch or the operating system, and not exclusively locked by another application.
Why is my webcam preview mirrored?
Previews are mirrored by default so moving feels natural, like a mirror. The people on your call see the unmirrored image. Toggle Mirror to compare; snapshots are always saved unmirrored, exactly as others see you.
Does the webcam test work on phones?
Yes. On iPhone and Android, open the page in Safari or Chrome, allow camera access and pick the front or back camera from the list. The Camera type row in All measurements shows which one is active.