AnyTool
Your files never leave your device. All processing happens locally in your browser.

How do I equalize an MP3 or boost the bass online without uploading it?

Open AnyTool's Audio Equalizer, drop in your file, and drag the 10 ISO bands (or switch to parametric mode with per-band frequency, gain and Q) while a live response curve and spectrum update and the audio changes in real time. Hit a preset like Bass Boost, Podcast or Vocal Clarity, A/B the result, then export WAV, MP3, M4A, OGG or FLAC with a built-in limiter so boosts never clip. Everything runs in your browser with the Web Audio API and a self-hosted ffmpeg engine — no upload, no watermark, no size cap, no CDN.

  • 10-band graphic + parametric EQ with a live frequency-response curve and spectrum
  • Bass Boost, Podcast, Vocal and per-genre presets, plus instant A/B bypass
  • Built-in limiter and output gain so boosts stay clip-safe
  • 100% in your browser — no upload, no watermark, no size cap, no CDN

What is

Audio equalization (EQ)

Equalization adjusts the level of specific frequency bands in an audio signal — boosting bass, cutting harshness or clarifying vocals. A graphic EQ uses fixed bands; a parametric EQ lets you set each band's centre frequency, gain and Q (bandwidth). A client-side EQ shapes and previews the sound in the browser with the Web Audio API without uploading the file.

Audio Tools

Related terms

parametric eqbass boostfrequency responsebiquad filterlimiter

How to Equalize Audio

Shape the frequencies of an audio file in your browser.

30 secWeb browser
  1. 1

    Add audio

    Drop in any audio file — it stays on your device.

  2. 2

    Adjust the bands

    Drag the EQ bands or pick a preset and hear the live response curve change in real time.

  3. 3

    Export

    A/B the result, then download as WAV, MP3, M4A, OGG or FLAC — nothing is uploaded.

Result: An equalized audio file

Frequently Asked Questions

No — the EQ runs entirely in your browser.

The file never leaves your device and there is no size or length cap, unlike Audioalter (server-side) or DoveSonic, which caps the free tier at 5 exports a day, 50 MB and 10 minutes.

Yes — a built-in limiter and live peak meter keep boosts clip-safe.

A brickwall limiter and output-gain trim catch peaks the moment a bass boost would clip, and you can preview the change in real time before exporting; most free EQs offer no clip protection.

WAV, MP3, M4A, OGG or FLAC.

The EQ render is encoded by a self-hosted ffmpeg engine to WAV, MP3 (320k), M4A (AAC), OGG (Vorbis) or FLAC, whereas the best free draggable rival (SoundTools) is WAV-only.

Detailed Explanation

Methodology

How the Audio Equalizer Works

AnyTool equalizes audio entirely in the browser with the Web Audio API. The file feeds one persistent graph of BiquadFilterNodes (low-shelf, peaking and high-shelf bands) into a limiter and an AnalyserNode, so dragging a 10-band graphic slider or a parametric band (frequency, gain, Q) changes the sound instantly with zero re-render. A requestAnimationFrame loop draws the exact combined response via getFrequencyResponse() over the live spectrum (getByteFrequencyData), and a one-key bypass routes the source straight through for A/B. On Apply, the identical chain is rebuilt in an OfflineAudioContext and rendered to PCM; WAV is written directly, and a self-hosted single-threaded ffmpeg.wasm engine (bundled core, no CDN) encodes MP3 (libmp3lame), M4A (AAC), OGG (libvorbis) or FLAC, with an optional limiter/loudnorm safety pass.

  • Runs client-side — the audio is never uploaded
  • Web Audio BiquadFilter chain with live response curve + spectrum
  • 10-band graphic and parametric (freq/gain/Q) modes
  • Built-in limiter and output gain keep boosts clip-safe
  • Self-hosted ffmpeg core (bundled) — no CDN
  • Export WAV/MP3/M4A/OGG/FLAC
Privacy & Security

Privacy vs Cloud Equalizers

Audioalter processes server-side, DoveSonic caps the free tier at 5 exports a day, 50 MB and 10 minutes (with a $5 unlock), and online video editors/desktop editing apps add a watermark or require sign-up. AnyTool equalizes locally, so the file never leaves the browser, there is no size or length cap, no watermark and no account. The strongest free client-side rival (WuTools) has no export beyond its own pipeline and no auto-EQ, while SoundTools is WAV-only — AnyTool adds full MP3/M4A/OGG/FLAC export and a clip-safe limiter.

Audio EQ: AnyTool vs typical tools
CapabilityAnyToolTypical tools
Data handlingIn your browserOften uploaded
Live response curveYes (real-time)Sometimes
Parametric QYesOften fixed bands
Output formatsMP3/M4A/OGG/FLAC/WAVOften WAV or MP3 only
Watermark / capNoneCommon

AnyTool is a privacy-first client-side audio equalizer — EQ runs locally and nothing is uploaded.