Frequency Analyzer Online: Live Spectrum and Spectrogram From Mic or File
RingtoneGenerator turns sound from your microphone or an audio file into a live frequency analyzer in your browser, free to try. See the spectrum with FFT sizes from 2048 to 32768, a scrolling spectrogram and the waveform, plus the dominant frequency with its note name and cents, a log or linear axis, peak hold and freeze. Open MP3, WAV and other audio files and download any view as a PNG. Nothing is uploaded: files play and are analyzed on your device.
- Free, no sign-up
- Spectrum, spectrogram, waveform
- FFT 2048 to 32768
- Files never uploaded
Dominant
-Hz
Note
-
Peak level
-dB
Resolution
5.86Hz/bin
See the spectrum of any sound
Use your microphone, or open an audio file. Everything is analysed in your browser; nothing is uploaded.
Frequency analyzer
Press Space or the mic button to start
Runs in your browser. Audio never leaves this device and nothing is saved unless you download it.
- SpaceStart / stop mic
- FFreeze
- VNext view
- LLog / linear
- HPeak hold
- SSave PNG
- OOpen file
- EscStop mic
Analyzer settings
5.86 Hz per bin, 171 ms window.
Good to know
- You see what your microphone captures, including its own coloration; many built-in mics pick up little below about 100 Hz.
- The highest frequency shown is half the sample rate (for example 24 kHz at 48 kHz).
- Levels are relative dBFS per FFT bin, not calibrated sound pressure.
- Bigger FFT sizes show finer frequency detail but react more slowly.
- Files are decoded by your browser: MP3, WAV, M4A/AAC, OGG/Opus and FLAC work in most current browsers, but support varies.
- The dominant frequency is the strongest peak. For voices and instruments it can be a harmonic rather than the pitch you hear.
- Audio is processed on this device. Nothing is uploaded or stored, and there is no sign-in.
What a Frequency Analyzer Shows
Every sound is a mix of frequencies: the thump of a kick drum near 50 to 100 Hz, a voice from about 100 Hz up to 4 kHz, the hiss of cymbals above 8 kHz. A frequency analyzer, also called an audio spectrum analyzer or audio frequency meter, splits that mix apart with a Fast Fourier Transform (FFT) and draws how loud each frequency is, many times a second. This one shows it three ways: a spectrum for this moment, a spectrogram for the last few seconds and a waveform for the raw signal.
- A hum in a recording that you cannot place.
- A whine from a charger, a fan or a TV.
- A mix that sounds muddy or harsh, and you do not know where.
- A "lossless" file that might once have been an MP3.
- A note you can hear but cannot name.
Why Use This Audio Spectrum Analyzer
A frequency visualizer that is quick to read and deep enough to trust.
Four live views
Spectrum, an online spectrogram, a waveform analyzer and a Split view, one click apart, from the mic or a file.
Note name and cents
An audio frequency detector that shows the loudest frequency in Hz, its note, like A4, and how many cents sharp or flat it is.
FFT 2048 to 32768
Pick fast updates or fine detail, down to under 1.5 Hz per bin at a 48 kHz sample rate.
Log or linear axis
A log axis spreads bass and treble the way you hear them; a linear axis shows harmonics evenly spaced.
Mic or audio file
Analyze a live sound, or open a song, voice memo or recording in the audio analyzer and watch it as it plays, on loop if you like.
PNG download, no upload
Save the view as a PNG. Files and microphone audio stay on your device.
How to Use the Frequency Analyzer Online
This online frequency analyzer needs no install, no account and no upload.
- 1
Pick a source
Press Start microphone, or press Open audio file (or drop one) to play it on your device and analyze it as it plays.
- 2
Choose the view
Switch between Spectrum, Spectrogram, Waveform and Split, set a log or linear axis and pick an FFT size.
- 3
Read and save
Read the dominant frequency and its note, hover to read any point, press Freeze at the right moment, then Download PNG.
Audio Analyzer Features: Spectrum, Spectrogram, Waveform and Notes
Echo cancellation, noise suppression and auto gain are switched off for the microphone, so this online audio frequency analyzer sees the sound as it is.
Live Spectrum With a Log or Linear Axis and Peak Hold
The spectrum draws level against frequency, bass on the left and treble on the right. On the log axis each octave gets the same width, so 50 to 100 Hz takes as much room as 5 to 10 kHz, which matches how you hear. Switch to linear to see harmonics as evenly spaced spikes. Peak hold leaves a thin line at the highest level each frequency reached, so a short whistle or a resonance stays visible after it stops, and Smoothing calms the curve. Hover or touch to read the frequency and level at any point, and set the dB range and Highest frequency to zoom in. As an audio spectrum analyzer it is a handy EQ guide: you see a boomy 200 Hz bump or a harsh 3 kHz peak before you reach for a filter.
See the SpectrumSpectrogram Analyzer With a Scrolling Waterfall
A spectrogram adds time. Each new slice of sound becomes a column of color, low frequencies at the bottom and high ones at the top, brighter where it is louder, and the picture scrolls along. Steady tones become flat lines, speech becomes stacked bands that bend with your voice, drums become vertical stripes and noise becomes a haze. Spectrogram speed sets how fast it scrolls, and the Split view puts the spectrum on top. This online spectrogram is where hidden things show up: a 50 or 60 Hz mains hum, the 15.7 kHz whine of an old tube TV, or a file that stops dead near 16 kHz because it was once an MP3. Freeze it to study a moment.
Open the SpectrogramPeak Frequency With Note Name and Cents
The readout names the dominant frequency, measured between FFT bins for a finer reading, for example 440.5 Hz, the note it is closest to, A4, and the distance in cents, +2. A cent is one hundredth of a semitone, so a whistle, a sung note, a guitar string or a beep can be checked against the note it should be. It works as an online frequency detector for steady sounds. With chords or busy music the loudest part wins, and that can be a harmonic rather than the note you hear, so hold one note and give the frequency analyzer a moment to settle.
Find the FrequencyWaveform Analyzer, FFT Size and Freeze
Switch to the waveform to see the raw signal, held steady the way an oscilloscope does, with about four cycles on Auto: a pure tone is a smooth wave, a square wave has flat tops, and clipping cuts the peaks off. As an audio waveform analyzer it pairs well with the spectrum, which shows the same sound as frequencies. The FFT size sets the trade-off between detail and speed. At 48 kHz, 2048 points gives 23.4 Hz per bin and moves quickly; 32768 points gives 1.46 Hz per bin but looks at about 0.7 seconds of sound at once. Freeze holds the picture while the sound goes on, and Download PNG saves what you see.
Try the WaveformFrequency Analyzer Demo: Spectrum and Note Readout
Pick a test sound to see what the frequency analyzer draws, its spectrum, spectrogram and peak note, then change the FFT size and the axis. The demo draws made-up signals and never asks for your microphone; press Hear it to play the sound quietly.
Made-up signals drawn in your browser. Nothing here uses the microphone.
Test sound
A2 at 110 Hz plus harmonics at 2, 3, 4 times; highs fade first.
FFT size
5.9 Hz per bin, 171 ms of sound per frame at 48 kHz.
Hear it plays 2 seconds at low volume. Small speakers may not play the 60 Hz hum at all.
A pure 440 Hz tone is one spike; a plucked string adds harmonics at 2, 3 and 4 times the frequency; mains hum sits at 60 Hz with its multiples; white noise spreads across everything. The frequency analyzer at the top draws your own sound the same way.
What You Can Spot in an Online Spectrogram
Four things the frequency analyzer makes easy to see and that are hard to hear.
Mains hum
A line at 50 Hz (Europe, Asia) or 60 Hz (the Americas), with its multiples, points to a ground loop. Built-in mics hear little below 100 Hz, so check files.
Fake lossless files
A file that cuts off sharply near 16 to 17 kHz was probably an MP3 at some point, whatever its name says.
Harmonics
A note is a stack of lines at 1, 2, 3 and 4 times its frequency. Their balance is why a violin sounds unlike a flute.
Test tones
Play a tone from the tone generator to see exactly where it sits, or a mosquito tone near 17 kHz to see if your mic reaches that high.
Online Audio Spectrum Analyzer vs Desktop and Hardware Tools
An online spectrum analyzer covers most everyday checks. Lab and compliance work still needs calibrated gear.
| Online Audio Spectrum Analyzer vs Desktop and Hardware Tools | RingtoneGenerator frequency analyzer | DAW analyzer plugin | Phone analyzer app | Hardware spectrum analyzer |
|---|---|---|---|---|
| Price | Free | Free to a few hundred dollars | Free to a few dollars | Hundreds to thousands of dollars |
| Install | None, runs in a tab | A DAW plus the plugin | App download | A separate device |
| Spectrum, spectrogram, waveform | Varies by plugin | Varies by app | Spectrum, often a waterfall | |
| Microphone and audio files | Tracks in a project | Mic, sometimes files | Electrical inputs | |
| Note name and cents | Some plugins | Some apps | ||
| FFT size | 2048 to 32768 | Usually adjustable | Varies | Set by the instrument |
| PNG export | Screenshot | Screenshot | On many models | |
| Files stay on the device | Depends on the app | |||
| Calibrated measurement |
Who Uses a Frequency Analyzer
Anyone who needs a sound frequency meter online, from students to sound engineers.
Musicians and producers
Use it as a spectrum analyzer for music: check the low end of a mix, compare it to a reference track or see which note rings out.
Podcasters and streamers
Find the hum, hiss or room boom under your voice after a quick mic test, before you record.
Students and teachers
Show harmonics, beats and pitch live in a physics or music class. A spectrogram analyzer on a projector makes sound visible.
Noise hunting
Track down a whine from a fan, charger or fridge with an online sound frequency analyzer, then see how loud it is with the decibel meter.
Speakers and rooms
Play a sweep from the tone generator into the frequency analyzer and watch where your room lifts or swallows the bass, then check it with a bass test.
Birds and nature
Open a field recording in the online spectrogram and see calls as shapes, handy for comparing two birds or two takes.
Frequency Analyzer FAQ
How to read it, what to set and what it cannot do.
Is this audio frequency analyzer online free?
Yes. The frequency analyzer is free, with no sign-up and no install, and it runs in modern browsers on computers and phones. Microphone audio and opened files are analyzed on your device and never uploaded.
What is the difference between a spectrum, a spectrogram and a waveform?
A waveform shows level over time, the shape of the signal itself. A spectrum shows how loud each frequency is right now. A spectrogram stacks spectrums over time as a colored picture. A waveform analyzer is best for clipping and timing; a frequency analyzer is best for tone, hum and pitch.
How do I find the frequency of a sound?
Press Start microphone, make the sound near the mic and read the dominant frequency above the view. As a sound frequency analyzer online it reads steady sounds best: a whistle, a beep, a hum or one held note. It is also a frequency detector online for any file you open.
Can I see an MP3 spectrogram?
Yes. Open or drop an MP3, WAV, M4A, OGG or FLAC file (support depends on your browser), and the spectrogram fills in as it plays, so you can see where the highs stop or find a noise. Used as a spectrum analyzer for audio files, it keeps them on your device; nothing is uploaded.
Can I use it as a song frequency checker?
Yes, for what a song is made of: its low end, its brightest parts, where an MP3 cuts off and which note is loudest at a moment. It does not identify songs, and it shows frequencies, not the key of the whole track.
What FFT size should I use?
In the frequency analyzer, start with 4096 or 8192 for music and voice. Use 2048 for fast changes like drums, and 16384 or 32768 to split two close tones or read a low note exactly. At 48 kHz, 2048 gives 23.4 Hz per bin and 32768 gives 1.46 Hz.
Should I use a log or linear frequency axis?
Use log for almost everything: it gives each octave the same width, like a piano keyboard. Use linear when you want to see harmonics as evenly spaced lines or study the very top of the range.
Can it tell me which musical note I am playing?
Yes, for one clear note. The frequency analyzer shows the frequency, the nearest note with A4 at 440 Hz, and how many cents sharp or flat it is. With chords it names the loudest part only.
Is this a professional audio analyzer?
It is a solid free audio analyzer for checks, teaching and mixing hints, not a professional audio analyzer for lab or certification work. Phone and laptop microphones are not calibrated, so levels are relative, not exact sound pressure.
Can I use it as an EQ spectrum analyzer while I mix?
Yes, as a guide. Open the bounced mix as a file in the audio analyzer, or play it through your speakers into the mic, and look for bumps and holes. Trust your ears and a reference track for the final call.
Is there a free spectrum analyzer for music?
This one: a free spectrum analyzer for music, voice and any other sound, with a spectrogram, a waveform and a note readout, right in your browser.
Analyzer or analyser: is this an audio spectrum analyser?
Yes. Analyser is the British spelling, so a frequency analyser, audio frequency analyser, audio analyser or sound spectrum analyser is the same tool. It works as a spectrum analyser online on any device.
Why does it show nothing above 16 or 20 kHz?
The top of the frequency analyzer scale is half the sample rate: 22.05 kHz at 44.1 kHz and 24 kHz at 48 kHz. Many phone and laptop mics fade out well before that, and many MP3s are cut near 16 kHz, so the top can look empty.
Can it pick up ultrasound or a dog whistle?
Mostly no. A dog whistle is often pitched above 20 kHz, beyond most microphones and beyond the 24 kHz ceiling at 48 kHz. High tones below that can show up if your mic reaches them.
Can I save the spectrogram as an image?
Yes. Press Download PNG to save the current spectrum, waveform or online spectrogram; press Freeze first to catch the exact moment.
Does it work on iPhone and Android?
Yes. As a sound spectrum analyzer online it runs in Safari and Chrome on phones. Phones may still shape the built-in mic a little, so a headset or external mic gives the cleanest picture.
More Sound and Device Tests
Make test sounds for the frequency analyzer, check the mic and measure the room.
Turn a Sound You Like Into a Ringtone
Found the bright part of a song in the audio analyzer? Cut it into a ringtone with our free ringtone maker, or make it louder for a noisy room.
Open the Frequency Analyzer
Press Start microphone or Open audio file, and read the spectrum, spectrogram, waveform and peak note live. This frequency analyzer is free, works as an audio spectrum analyzer online with no sign-up, and nothing you play is uploaded.