How-to Guides Design & Media

How to Test Your Webcam, Microphone and Screen

Check your camera, microphone, speakers, display and keyboard before a call or after buying new gear, using browser tests that upload nothing.

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Steps

  1. Test the webcam

    Open the Webcam Test, press Start camera and allow access. Check the resolution and measured frame rate it reports, try the 720p, 1080p and 4K requests, and look at framing and lighting. The camera chooses the closest mode it supports, so the result can differ from what you requested.

  2. Test the microphone

    Open the Microphone Test, press Start Microphone and speak at your normal distance. Speech usually sits between about -30 and -12 dBFS. If the meter barely moves, move closer or raise the input volume; if it shows clipping, lower the gain. Record five seconds and play it back to judge clarity and noise.

  3. Compare browser processing

    Switch the browser's noise and echo processing on and off in the microphone test and record again. Processing helps on a noisy desk and can cut off quiet speech, so use whichever sounds better on playback.

  4. Check the speakers or headphones

    Start low and use the Tone Generator with the Balance control to play a tone in the left channel, then the right, to confirm the channels are the right way round. A slow sweep from 20 Hz upward reveals rattles and cut-offs.

  5. Look for dead pixels

    Clean the screen, then run the Dead Pixel Test full screen. Look closely on each colour: a dead pixel stays black and shows best on white, a stuck pixel stays one colour, and a hot pixel stays white and shows best on black. Wipe the spot to rule out dust.

  6. Check every key

    Open the Keyboard Tester and press every key. Keys that never light up are dead, a key flagged as chatter registers twice for one press, and holding several keys shows how many your keyboard can report at once.

What you need

A device with the hardware you want to check, a modern browser, and permission to use the camera and microphone when it asks. Test new equipment soon after it arrives, because return and warranty windows are limited.

Reference values for test tones

The tone generator shows the period and wavelength of the tone; the same values follow from the speed of sound in air (about 343 m/s at 20 °C):

Frequency Use Period Wavelength in air
50 Hz Mains hum (50 Hz regions) 20.00 ms 6.860 m
100 Hz Low bass / subwoofer 10.00 ms 3.430 m
440 Hz Concert pitch A4 2.27 ms 0.780 m
1,000 Hz Standard test tone 1.00 ms 0.343 m
10,000 Hz High-frequency hearing check 0.10 ms 0.034 m

What each result means

Test Good sign Problem sign
Webcam Expected resolution, steady frame rate Low resolution or a frame rate far below what is reported
Microphone Speech peaks around -30 to -12 dBFS Barely moves (too quiet), or shows clipping (distorted)
Speakers Tone comes from the channel you pan to Left and right swapped, or one channel silent
Screen Uniform colour on every test colour A dot that stays black, white or one colour
Keyboard Every key lights up once per press A key that never lights up, or lights twice (chatter)

Common pitfalls

  • Testing with the wrong device selected. Choose the right camera or microphone from the device list when several are connected.
  • Blaming the website. If a call app cannot see your camera, check whether another app is already using it.
  • Mistaking dust for a dead pixel. Wipe the screen and check whether the spot moves.
  • Forgetting the volume. Start low with the tone generator and raise it slowly.
  • Judging chatter after one press. Press a suspect key several times before deciding it is faulty.

Try these tools

Webcam Test

Free online webcam test.

Microphone Test

Free online microphone test.

Tone Generator

Play sine, square, sawtooth or triangle waves from 20 Hz to 20 kHz, pan left or right to test each speaker.

Dead Pixel Test

Free dead pixel test.

Keyboard Tester

Press each key to light it up on an on-screen layout, see key, code and keyCode values.

See also

  • Glossary Decibel (dB)
    A decibel is a logarithmic unit that compares two levels of sound, signal or power; in digital audio, level is measured in dBFS.
  • Glossary Frame rate
    Frame rate is how many video frames are shown per second (fps), such as 24, 25, 30 or 60.
  • Glossary Hertz (Hz)
    A hertz is one cycle per second, the unit of frequency; for sound it sets the pitch.
  • Glossary Resolution and PPI
    Resolution is the number of pixels in an image (such as 1920 × 1080).
  • Glossary Dead pixel
    A dead pixel is a screen pixel that stays permanently dark, while a stuck pixel is locked on one colour.

Frequently Asked Questions

No. Camera video, microphone sound and key presses stay in your browser tab. The microphone test can record five seconds to play back to you, but that clip is not sent anywhere.

Allow access when the browser asks, or click the camera or lock icon in the address bar if you blocked it earlier. An 'in use' error means another app such as Zoom or Teams is holding the device; close it and retry. Also check for a privacy shutter or a function key that disables the camera.

No. A slow sweep gives an informal check of your high-frequency hearing, but it is not a medical test. Keep the volume low, because loud tones, especially high frequencies on headphones, can damage hearing.

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