01
Speaker Test
Plays test tones through the left, right and both channels so you can confirm every speaker is…
Live Spectrum Analyser
Shows what your microphone hears as a live frequency spectrum on a logarithmic scale, with the peak frequency named.
Audio Tests
Nothing uploaded
No sign-up
Free, unlimited
The test starts automatically — follow the prompts above.
In short
A spectrum analyser should use a logarithmic frequency axis, because that is the only scale that matches hearing — an octave occupies the same width whether it runs from 100 to 200 Hz or from 5 to 10 kHz. On the linear axis most simple analysers default to, everything below 1 kHz is squeezed into the first few percent of the width, which is where nearly all musical information lives. The resolution is set by the FFT size divided by the sample rate: a 4096-point FFT at 48 kHz gives about 11.7 Hz per bin, so a bigger FFT sees closer frequencies apart but responds more slowly.
How to use the Live Spectrum Analyser
- Allow microphone access when asked.
- Make a sound — the peak frequency is named below the display.
- Raise the FFT size to separate close frequencies.
- Press Reset to stop the microphone.
About the Live Spectrum Analyser
The Live Spectrum Analyser shows what your microphone hears as a live frequency spectrum on a logarithmic scale, with the peak frequency named. It runs as plain JavaScript inside the page, which means there is no upload step, no queue and no size limit imposed by a server — the only limit is your own device.
What people use it for
- Finding the frequency of a hum or a whine.
- Checking what a room does to a tone.
- Seeing which frequencies an instrument actually produces.
Details
| Axis | Logarithmic by default — an octave is an octave |
|---|---|
| Resolution | Sample rate ÷ FFT size per bin |
| 4096 at 48 kHz | About 11.7 Hz per bin |
| Trade-off | A bigger FFT sees finer detail and reacts more slowly |
| Privacy | The stream stays in this tab and is never recorded |
Smoothing is a display choice, not a measurement one. A high value gives a calm, readable display that lags reality; zero shows every frame exactly and flickers. Neither is more correct — pick by what you are trying to see.
Where this tool stops
Shows the microphone's view of the room. It is not calibrated, and the microphone's own frequency response is baked into everything you see.
Frequently asked questions
Why is the bass end so wide?
Because the axis is logarithmic, and that is deliberate. Hearing works in ratios rather than differences, so the octave from 100 to 200 Hz deserves the same width as the one from 5 to 10 kHz. A linear axis gives the top octave half the screen and crushes everything musical into the left edge.
What FFT size should I use?
Depends what you are looking for. A big FFT resolves close frequencies — useful for identifying a hum or separating two nearby tones — but averages over a longer window, so transients smear. A small one follows fast changes and cannot tell 100 Hz from 110. 4096 is a fair middle.
Can I trust the levels?
Relatively, not absolutely. You are seeing the room and the microphone as much as the source, and a laptop or phone microphone rolls off sharply below about 100 Hz — so bass that looks missing may simply be unrecorded. Use it to compare, not to measure.
Do I need an account to use the Live Spectrum Analyser?
There is no cost and no cap. The Live Spectrum Analyser is not a demo of a paid product, so nothing is held back or watermarked.
Is what I paste into the Live Spectrum Analyser stored?
No. The Live Spectrum Analyser runs entirely in your browser using JavaScript. Your input never reaches inputtesthub.com or any third party — open your browser's Network tab while you use it and you will see no request go out.
What is the Live Spectrum Analyser used for?
Typical uses: finding the frequency of a hum or a whine. Checking what a room does to a tone. Seeing which frequencies an instrument actually produces. It is built for exactly those cases rather than being a general-purpose tool with this bolted on.
Where does the Live Spectrum Analyser stop being reliable?
Shows the microphone's view of the room. It is not calibrated, and the microphone's own frequency response is baked into everything you see. Knowing where a tool stops being trustworthy matters more than the cases where it works.
What are the key numbers for the Live Spectrum Analyser?
Axis is Logarithmic by default — an octave is an octave. Resolution is Sample rate ÷ FFT size per bin. 4096 at 48 kHz is About 11.7 Hz per bin. These are printed on the page itself, so you do not have to take them on trust.
Does the Live Spectrum Analyser need an app or a driver?
No installation, no extension and no driver. The Live Spectrum Analyser uses the browser's own device APIs and begins as soon as the page loads, so there is nothing to press first. Press Reset at any point to start over with a clean slate.
Related audio tests tools
All 1802
Left Right Speaker Test
Plays a tone in one channel at a time, with a panel that lights up on the matching side so you…
03
Headphone Test
Checks both headphone drivers with separate left and right tones, and confirms the stereo…
04
Stereo Test
Confirms that stereo separation is working by playing distinct tones in each channel and then…
05
Audio Balance Test
Alternates between channels so you can hear whether one side is quieter, and adjust the…
06
Online Tone Generator
Generates a pure tone at any frequency from 1 Hz to 22 kHz, with a choice of waveform, channel…
07
Bass Test
Sweeps from 20 Hz up to 200 Hz so you can hear exactly how low your speakers or headphones…
08
Subwoofer Test
A slow sweep from 10 Hz to 120 Hz for checking how deep a subwoofer really goes and where it…
09
Treble Test
Sweeps from 2 kHz to 20 kHz to check tweeter performance and find where high-frequency…
10
Frequency Sweep Test
Glides smoothly across the whole audible range so you can hear dips, peaks and rattles in a…