What is the difference between this and the ordinary tone generator?

Two things. The level here is entered in dBFS and converted to the corresponding linear amplitude, so the file is a calibrated reference rather than a proportion of full scale; and the tone can burst on and off repeatedly with shaped edges, which is what makes it useful for sustained measurement of a system.

What is spectral splatter and why does it matter?

It is the spread of energy across many frequencies that a sudden switching edge produces. A repeating burst with hard edges would add clicks at the burst rate and fill the spectrum with content that was never intended, which would make any measurement meaningless. The ten millisecond fades at each burst edge prevent it.

What does the level setting mean exactly?

It is the peak amplitude of the tone relative to digital full scale. Minus twenty dBFS means the waveform's peak sits a tenth of full scale, minus six is about half, and zero is the maximum. It is a peak figure, so it does not describe how loud the tone will sound.

Can I make a rhythmic burst pattern?

Only coarsely, because the on and off times are set in seconds with a tenth-second step. That is deliberate: the burst mode exists to give a system something to measure over a period rather than to produce a musical rhythm. For a tempo with accents, the click track and metronome generators are the right tools.

Why does a continuous tone click at the start?

Because the file begins at full amplitude at a point that is almost never a zero crossing of the waveform. That starting step is audible as a click. Setting a burst time and treating the silent intervals as boundaries avoids it, or the file can be faded at each end afterwards.

Test Tone Generator

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Test Tone Generator produces professional reference tones with the level set directly in dBFS and an optional burst pattern that switches the tone on and off at a fixed rate. It is built for measurement rather than for listening.

What is Test Tone Generator?

Choose a shape, a frequency, a level in decibels, a duration and a burst pattern, then generate. The result is a mono WAV with a player and a download control, ready to use as a reference signal.

The controls in detail:

A wave shape selector offering sine, square, sawtooth, triangle and pulse.
A frequency from one to twenty thousand hertz, defaulting to one thousand, the traditional reference.
A level from minus sixty to zero dBFS, defaulting to minus twenty, converted to a linear amplitude internally as ten to the power of the level divided by twenty.
A duration from a tenth of a second to sixty seconds, defaulting to five.
Burst on and burst off times in seconds, so the tone can repeat rather than run continuously; setting the off time to zero produces a continuous tone.

The burst mode is the feature that distinguishes this tool from the plain tone generator, and its implementation shows why. A tone that is switched on and off would produce a hard edge at every transition, and because those edges repeat at the burst rate they add a wide spread of high-frequency energy, a phenomenon known as spectral splatter. Ten millisecond fades are applied at the beginning and end of each burst to prevent that, so the repetition is clean and the measurement means what it appears to mean. The decibel level control is the other professional touch. Because amplitude is computed from the level rather than set as a percentage, minus twenty dBFS really is a tenth of full scale in voltage terms, which makes the file usable as a calibrated reference for setting meters, checking gain structure, or establishing a known level on a recording chain. A reference tone also makes it obvious whether a device is behaving: play minus twenty dBFS into a meter that should read minus twenty and any difference is a gain error somewhere in the chain rather than a matter of opinion.

What the tool does not offer:

Only one tone at a time, with no swept or modulated options.
The level is a peak value rather than a loudness figure, so it does not describe perceived level.
Burst timing is in whole seconds with a tenth-second step, which is too coarse for rhythmic use.
No fade is applied to the file's own boundaries, only to the bursts, so a continuous tone can still click at its very start and end.
Mono output only, with no per-channel or stereo reference patterns.
The maximum duration is one minute per generated file.

Use it when a known level and a known frequency matter: setting a mixer's gain structure, checking that a meter reads what it should, testing whether a device distorts at a stated level, or producing a repeating tone so a system can be measured without anyone holding a button down. When a listening tone rather than a measurement reference is wanted, the tone and sine generators present the same synthesis with a simpler amplitude control, and the sweeps cover the case where the frequency needs to move.

How to use Test Tone Generator

Choose a wave shape and the frequency you need.
Enter the level in dBFS, using minus twenty as a safe starting point for most equipment.
Set the duration, then set the burst on and off times, or leave the off time at zero for a continuous tone.
Press generate, then download the file and use it as a reference signal.

When to use Test Tone Generator vs related tools

Test Tone Generator is the measurement tool of this family, since the level is stated in dBFS and the tone can burst. Tone Generator and Sine Wave Generator produce similar signals with a simpler amplitude control, better suited to listening than to calibration. When the frequency has to move rather than hold, Frequency Sweep Generator and Sweep Tone Generator cover the sweep case.

Privacy & Security

This tool runs entirely in your browser — no data ever leaves your device. There is no server round-trip, no upload, no logging, and no account required. Your input is processed locally using client-side JavaScript and is never stored, transmitted, or accessible to anyone else. When you close the tab, everything disappears.