Online Tone Generator – Free Sine Wave & Frequency Generator

What is an online tone generator?

An online tone generator plays a steady audio tone in your browser at the exact frequency you pick — no app, no audio file, no microphone. This free frequency generator online synthesizes every tone live with the Web Audio API inside your own browser, so it runs in current Chrome, Edge, Firefox or Safari without an account or install and nothing is uploaded. Start with 440 Hz sine on Both speakers near 12% volume, press Play, then raise the slider one step at a time until the pitch sits clearly above room noise. Dragging the frequency slider while a tone plays bends the pitch live, and Auto stop cuts playback after 5, 30 or 60 seconds when you want a bounded burst for a high pitch.

Sine wave generator and other waveforms

Sine gives you the purest single pitch, which makes this sine wave generator mode the best choice when you ask whether a driver still reproduces 90 Hz or 3 kHz at all. Triangle sounds softer around the edges, while square and sawtooth add stacked harmonics that read as harsh or buzzy — keep those two near 8 to 10%. Both sends the same signal to each side, Left isolates the left speaker or earcup, Right isolates the right, and that split settles arguments fast when one earbud went quiet. Expect little phones and thin laptops to fade below roughly 150 to 200 Hz; a missing 40 Hz rumble on that hardware says more about cabinet size than about your audio file.

Online frequency generator: range, presets and live pitch

Use this online frequency generator anywhere from 20 Hz to 20 kHz. Tap 220 Hz for low-mid warmth, 440 Hz concert pitch for a neutral reference, 1 kHz for channel matching, 4 kHz for presence and sibilance checks, or 8 kHz for top-octave hiss. Everything is synthesized locally, so the frequency readout is the requested digital frequency — what you hear still depends on your speaker, Bluetooth codec and room. Open the frequency spectrum in a second tab, play 220 Hz here, then 4 kHz, and watch the energy hump march from left to right.

Four speaker checks that actually tell you something

You moved a bookshelf pair and the left one now sounds thin. Play 120 Hz sine on Both at modest level, switch to Left only, then Right only, and listen for equal weight — a 20-second A/B like that exposes a loose plug quicker than any playlist. Your right earbud dropped in volume last week. Run 1 kHz Left, then Right, at the same slider position; if Right needs three or four extra clicks to match, clean the mesh or check balance settings before buying a replacement. You want a steady reference while reading about calibration. Hold 1 kHz sine for 30 seconds and compare two setups, remembering a browser tone is a pitch reference rather than a level reference. For a full sweep instead of a steady tone, run the speaker test 20 Hz – 20 kHz sweep.

Safe use: volume cap, hearing and small speakers

Start at the lowest volume that works, keep tones short at high frequencies, and stop immediately if playback feels uncomfortable. Never test hearing at high volume — the hearing age test runs at a fixed moderate level for exactly this reason. Never raise the volume to hunt a pitch you cannot hear, especially past 12 kHz, because discomfort arrives late at those frequencies and the 25% cap exists to keep a slip from blasting full scale. Phone speakers compress bass, Bluetooth codecs shave extreme treble, and room modes boost some notes near walls while swallowing others in the middle of the room, so walk two steps and re-listen before you blame a speaker.

What this frequency generator cannot tell you

A tone tells you a pitch path works, never how loud your room is in decibels and never how your hearing thresholds score — chase those questions with the online decibel meter and the screening test instead. For everyday level context, skim the decibel comparison chart, and for method questions browse the frequently asked questions.

What it is good for

Checking a speaker still plays a given pitch, comparing left and right channels with the speaker test, producing a steady 1 kHz reference for calibration comparisons, and demonstrating the frequency spectrum live: play a tone here and watch the meter spectrum react in another tab.

Hearing age test → · Speaker test → · Open the decibel meter →