Equalize an Audio File

Pick an audio file and set bass, mid or treble gains — it's equalized in your browser, nothing is uploaded.

Equalize audio in your browser

Pick an audio file and set how much to boost or cut each band — the EQ is applied with ffmpeg, entirely in your browser. Bass is a low shelf around 100 Hz (warmth, boominess), Mid a 1 kHz peaking band (vocal presence, "boxiness"), and Treble a high shelf from about 3 kHz up (brightness, hiss). Gains are in decibels from -20 to +20; a band left at 0 is untouched, and at least one band must be set.

Worked example

A phone-recorded interview that sounds dull and slightly boomy: upload interview.m4a, set Bass to -4 and Treble to 5, leave Mid at 0 — the result interview-eq.mp3 has the low-end rumble tamed and the voices clearly brighter. Too harsh? Drop treble to 3. Voice still buried? Add Mid 3 for presence.

Which band does what

Bass (low shelf, ~100 Hz) — + warms up thin recordings; - tames boomy rooms, wind rumble and mic handling noise.
Mid (peak, 1 kHz) — + brings vocals forward; - fixes a "boxy" or honky character.
Treble (high shelf, ~3 kHz+) — + adds clarity and air to dull audio; - softens hiss, sibilance and harshness.

Limits and edge cases

Input files up to 10 MiB; any format ffmpeg can decode works.
Gains are capped at ±20 dB per band — bigger moves are almost never what a recording needs and mostly add distortion or noise.
Large boosts can push loud audio into clipping; if the result crackles, cut the opposite bands instead of boosting (e.g. -6 bass instead of +6 treble), or lower the overall volume first with audio-volume-adjust.
An EQ shapes tone, it can't isolate or remove a voice/instrument, and boosting treble can't restore detail a low-bitrate encode threw away.
Output is re-encoded (mp3/ogg at 192 kbps; wav/flac lossless; m4a AAC). Embedded album art is dropped.

FAQ

What do bass, mid and treble actually change?

They're the three classic tone-control bands: bass shapes everything below roughly 100 Hz (kick drums, rumble, warmth), mid works around 1 kHz where voices live, and treble shapes the top from about 3 kHz (clarity, hiss, cymbals). Positive dB values make that band louder, negative quieter, 0 leaves it alone.

How many dB should I move a band?

Start small: 3-6 dB is clearly audible, and most real-world fixes stay under ±8 dB. Cutting usually sounds more natural than boosting. The ±20 dB range exists for rescue jobs, not everyday tweaks.

Why does my boosted audio sound distorted?

Boosting a band raises peaks — audio already near full scale then clips. Try cutting the other bands instead of boosting one (the tonal balance change is the same), or run the file through audio-volume-adjust with a few dB of cut first, then equalize.

Can this remove background noise or vocals?

No — an equalizer changes the level of frequency bands, and noise or vocals overlap the same bands as everything else. A treble cut can soften hiss and a bass cut can tame rumble, but full removal needs dedicated denoise/source separation tools, which this isn't.

Is my audio uploaded anywhere?

No. The page downloads an ffmpeg WebAssembly build once and then processes your file locally in the browser tab — the audio never leaves your device.

Developer & Automation Access

Run it from the terminal

Same engine as this page, headless — via the gizza CLI:

gizza tool audio-eq 'url=https://example.com/input' 'bass=0' 'mid=0' 'treble=0' 'format=mp3'

New to the CLI? Get gizza →

Open it by URL

Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:

https://gizza.ai/tools/audio-eq/?url=https://example.com/input&bass=0&mid=0&treble=0&format=mp3