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About this tool
Test your microphone online: live level meter, waveform and spectrum, peak and noise-floor dB, clipping alerts and a 5 or 10 second playback recording.
This mic test opens your microphone with the browser's getUserMedia API and feeds it into a Web Audio analyser that is never connected to your speakers, so there is no feedback. Every animation frame it measures the RMS level and the absolute peak in dBFS, draws the waveform and a 40 Hz to 16 kHz spectrum, and flags clipping when samples reach 99% of full scale. The noise floor is the quietest 10% of the last six seconds of readings. You can pick any input device, switch echo cancellation, noise suppression and auto gain on or off, and record a 5 or 10 second clip to hear yourself. Audio never leaves your device.
Open Mic Test on AltFTool — it loads instantly in your browser.
Choose your device in the Microphone list (or leave System default) and press Start test; allow microphone access when the browser asks.
Speak at your normal distance and watch the Input level (dBFS) meter: the status pill reads Good level when speech sits between −30 and −10 dB, and a Clipping warning appears if peaks hit 99% of full scale.
Stay silent for a few seconds to read the Noise floor tile, then tick Echo cancellation, Noise suppression or Auto gain control to compare how the browser processes your voice.
Press Record 5 s sample (or pick 10 s), play the clip back in Record & play back, and use Copy report to paste the device, sample rate and dB readings into a support ticket.
RMS level, a 2-second peak hold, session max peak, session average and noise floor are all shown in dBFS, so you can compare settings and devices objectively.
Record a 5 or 10 second sample and play it straight back, with the same echo cancellation, noise suppression and auto-gain settings a call app would apply. Download the clip if you want to keep it.
Blocked permission, missing device, a mic held by another app and a silent input each get a specific explanation and steps, instead of a blank meter.
The analysis and recording run locally with Web Audio and MediaRecorder. Nothing is uploaded, and only your device choice and toggles are remembered in this browser.
| RMS level | Status shown | What to do |
|---|---|---|
| Below −70 dB | No signal | Check mute switch, device choice and OS input volume |
| −70 to −45 dB | Very quiet | Raise input gain or move closer to the mic |
| −45 to −30 dB | Quiet | Usable; a little more gain helps |
| −30 to −10 dB | Good level | Ideal range for calls, streams and voice-over |
| −10 to −3 dB | Loud | Lower gain slightly to leave headroom |
| Above −3 dB / peaks at 0 dB | Too hot / Clipping | Reduce gain; clipped audio is permanently distorted |
Levels are digital (dBFS), measured after any browser processing you enable. They are not sound-pressure readings and depend on your gain setting.
Press Start test, allow access when the browser prompts, and speak. If the level meter moves and the status reads Good level or Quiet, the microphone works. To check quality as well as presence, record a 5 or 10 second sample and play it back through your headphones.
The usual causes are a hardware mute switch, the wrong device selected, the operating system input volume at zero, or another app holding the microphone. After five seconds of silence the tool shows a checklist. Also confirm the site has microphone permission in the address-bar lock icon.
For speech, aim for an RMS level between about −30 and −10 dBFS with peaks staying under −3 dBFS. Much quieter and listeners will turn you up along with the background noise; peaks at 0 dBFS clip and distort. The meter colours change from green to amber at −12 dB and red at −3 dB.
dBFS stands for decibels relative to full scale. 0 dBFS is the loudest value digital audio can represent, so every real reading is negative. −6 dBFS is half the full-scale amplitude and −20 dBFS is a tenth. It measures the signal level in your computer, not the loudness of the room in dB SPL.
The noise floor is the level of the signal when you are not speaking: fans, hum, traffic and the microphone's own hiss. This tool takes the quietest 10% of the last six seconds of readings. Below about −60 dBFS is a quiet setup; above −40 dBFS the background will be clearly audible on calls.
For calls on laptop speakers, yes: echo cancellation stops others hearing themselves and noise suppression removes steady fan noise. For music, podcasts or a good headset you may prefer them off to keep the natural sound. Toggle them here and record a sample each way to compare.
Audio is processed only in your browser tab. Recording happens only when you press Record, the clip is kept in memory until you leave the page, and nothing is sent to a server. The only thing stored is your chosen device and toggle settings, in this browser's local storage.
Click the lock or tune icon left of the address, find Microphone and set it to Allow, then reload or press Try again. On macOS also enable the browser in System Settings › Privacy & Security › Microphone; on Windows check Settings › Privacy & security › Microphone.
The recording includes any browser processing you enabled and is compressed with the Opus or AAC codec your browser supports. Bluetooth headsets also drop to a narrow-band call profile while the microphone is active, which makes voices sound thinner. Wired or USB microphones avoid that.
Yes. After the first permission prompt the Microphone list shows every audio input your browser can see, such as the built-in array, a webcam mic and a headset. Selecting one restarts the test on that device, and your choice is remembered for next time.