Free Online Audio Equalizer

What Is an Equalizer?

An equalizer (EQ) is a signal processing tool that adjusts the volume of specific frequency ranges within an audio signal. Unlike a simple volume control, an equalizer lets you selectively boost or cut bass frequencies, midrange frequencies, and treble frequencies — independently and with precise control. This lets you shape the tonal character of any sound: make a voice clearer, add weight to a kick drum, tame harsh treble, remove muddiness from a recording, or give a mix brightness and air.

This free online equalizer processes your audio entirely inside your browser using the Web Audio API. Nothing is uploaded to a server, there is no account to create, and there is no software to install — you can open the page, load an MP3 or WAV, adjust bass and treble to taste, and download the result.

Graphic EQ vs. Parametric EQ: What's the Difference?

A graphic equalizer divides the frequency spectrum into a fixed number of bands — typically a 10-band or 31-band layout — and gives you one gain slider per band. All you control is how much to boost or cut each fixed band. A parametric equalizer gives you full control over three parameters per band: frequency (where in the spectrum the filter acts), gain (how much to boost or cut), and Q (the bandwidth — how wide or narrow the filter's effect is).

The Graphic EQ tab in this tool is a visual parametric equalizer: you click and drag nodes directly on the frequency response curve to control all three parameters at once, with a live spectrum analyzer running behind the curve so you can see exactly which frequencies are present in your audio as you shape them.

Vintage-Style Channel Equalizers Explained

Alongside the graphic EQ, this tool includes four channel-strip equalizers modeled on the character of classic studio hardware. Each one reproduces the band layout, frequency choices, and general tonal behavior of a well-known design — not the exact circuit. They are provided as style emulations to give you a fast starting point with a recognizable sonic character.

Neve 1081 Style — The Four-Band British Console Sound

The original Neve 1081, manufactured by Neve Electronics in the early 1970s, is a four-band parametric equalizer and microphone preamplifier. It appeared in large-format consoles used on countless recordings from the golden era of studio production. It features a high-frequency shelving band (10kHz, 12kHz, 16kHz, or 20kHz), a high-midrange peaking band (1.5kHz to 16kHz with a Hi-Q option), a low-midrange peaking band (220Hz to 7.2kHz with a Hi-Q option), and a low-frequency shelving band (35Hz to 220Hz). Its characteristic sound — aggressive treble boosts that stay smooth rather than harsh — comes from an inductor-based filter design and transformer saturation in the signal path. Our 1081 Style equalizer mirrors that band layout and voicing so you can dial in the same broad, forward brightness.

Neve 1073 Style — The Most Famous EQ Ever Built

The original Neve 1073 is a three-band equalizer and microphone preamplifier module from 1970, widely considered one of the most musically pleasing equalizers ever designed. Its high-frequency shelf operates at 12kHz or 16kHz; the single midrange band selects from 360Hz, 700Hz, 1.6kHz, 3.2kHz, 4.8kHz, or 7.2kHz; the low-frequency shelf selects from 35Hz, 60Hz, 110Hz, or 220Hz; and a steep 18dB/octave high-pass filter completes the circuit. Its simplicity is its genius — the limited frequency choices are each chosen to be maximally useful. Engineers describe its boosts as "musical": they enhance without adding harshness. Our 1073 Style equalizer follows the same three-band structure and stepped frequency choices.

API 550b Style — The American Punch Machine

The original API 550b is a four-band proportional-Q equalizer in the 500-series modular format, evolved from the API 550a of 1967. Its four bands have overlapping selectable frequency points: Low (30–300Hz), Low-Mid (75Hz–1.5kHz), High-Mid (800Hz–12.5kHz), and High (2.5kHz–20kHz), each providing ±12dB of boost or cut. The proportional-Q design automatically narrows the bandwidth at higher gain settings, which keeps heavy boosts focused and prevents muddiness. The result is a forward, punchy character heard on countless rock, hip-hop, and pop records — the opposite of the warm British sound. Our 550b Style equalizer reproduces the proportional-Q behavior and stepped frequency layout.

Pultec EQP-1A Style — The Passive Tube Legend

The original Pultec EQP-1A, designed by Pulse Techniques in the early 1950s, is a passive tube program equalizer. Unlike active transistor or op-amp designs, it uses passive filter circuits with a tube amplifier to make up gain. Its most famous feature is the simultaneous Boost and Attenuate controls on the low-frequency section (20, 30, 60, or 100Hz): boosting and attenuating the same frequency at once creates a unique filter shape — an enhanced low end with a tighter, faster-decaying bass response that adds weight without mud. This "low-end trick" is one of the best-known techniques in mixing and mastering. The high-frequency section provides smooth boost and attenuation from 3kHz to 16kHz. Our EQP-1A Style equalizer implements the same simultaneous boost/attenuate behavior so you can use the trick yourself.

Neve, API, and Pultec are trademarks of their respective owners. SoundTools is not affiliated with, endorsed by, or sponsored by any of these manufacturers. Preset names are used only to describe the sonic character being emulated.

How to EQ Vocals: A Quick Guide

Equalizing vocals is one of the most common audio tasks. Here's a practical workflow using this free online equalizer:

• High-pass filter at 80–120Hz: Nearly all vocals have no musical content below 100Hz — just room noise, handling noise, and proximity-effect buildup. Apply a 12–24dB/octave high-pass at 80–100Hz to clean up the low end without thinning the voice.
• Cut muddiness at 200–400Hz: If the voice sounds boxy, cloudy, or like it was recorded in a bathroom, try a gentle cut (3–5dB) with a moderate Q around 250–350Hz.
• Presence boost at 2–5kHz: This range controls intelligibility and bite. A gentle boost here (2–4dB, wide Q) helps vocals cut through a mix and improves clarity.
• Air at 10–16kHz: A high-shelf boost above 10kHz adds "air" and openness. The 1081 Style and 1073 Style equalizers are good choices here — their treble shelves add brightness without harshness.
• De-harsh at 3–6kHz if sibilant: If the vocal is too bright or sibilant, a narrow cut around 4–6kHz can tame the harshness.

How to EQ a Mix: Tips for Common Instruments

• Kick drum: Boost around 60–80Hz for "thump," cut around 200–300Hz to reduce muddiness, boost around 2–5kHz for "click" and attack.
• Snare: Boost around 100–200Hz for body, cut muddiness at 300–500Hz, boost around 5–8kHz for snap and crack.
• Bass guitar: High-pass at 30–40Hz to remove sub-rumble, boost around 80–120Hz for the fundamental, boost around 800Hz–1kHz for definition and presence in the mix.
• Electric guitar: High-pass at 80–100Hz, cut muddiness at 200–400Hz, add presence and bite at 2–4kHz.
• Acoustic guitar: High-pass at 80Hz, gentle boost at 2–5kHz for sparkle, high-shelf boost at 10kHz for air and brightness.
• Piano: Cut low mud at 200–300Hz, gentle presence boost at 2–4kHz, air at 8–12kHz.

How This Equalizer Compares to Other EQ Tools

Frequently Asked Questions

What is an online equalizer?

An online equalizer (or online EQ) is a browser-based tool that lets you boost or cut specific frequency ranges in an audio file without installing any software. This free online equalizer processes your audio entirely inside your browser using the Web Audio API — nothing is ever uploaded to a server, and no account is required.

What is the difference between a graphic EQ and a parametric EQ?

A graphic equalizer has a fixed set of frequency bands — commonly a 10-band or 31-band layout — with only the gain (boost or cut) adjustable per band. A parametric equalizer lets you control frequency, gain, and Q (bandwidth) for each band, giving far more surgical control. Most professional mixing is done with parametric EQs. The Graphic EQ tab in this tool is a parametric equalizer displayed graphically: you drag nodes on the response curve to control all three parameters at once.

How do I boost bass or treble with this equalizer?

To boost bass, add or drag a band down in the low frequencies — roughly 60–150Hz for the fundamental weight of a track — and raise its gain. To boost treble, do the same in the 8–16kHz range using a high shelf, which lifts everything above the chosen frequency. Keep boosts modest (3–6dB is usually plenty) and use the spectrum analyzer to see what you're actually changing. If you only want a quick low-end lift, our Bass Booster does that in one click.

What is Q in an equalizer?

Q (quality factor) controls the width or bandwidth of a filter's effect. A high Q value (for example Q = 10) creates a very narrow, surgical peak or notch — useful for removing a specific resonance or hum. A low Q value (for example Q = 0.5) creates a broad, gentle curve that affects a wide range of frequencies — useful for tonal shaping and color. In the Graphic EQ, scroll the mouse wheel on any filter node to adjust its Q.

What are the vintage-style channel EQs?

The tool includes four channel-strip equalizers whose band layouts, frequency choices, and tonal behavior are modeled on the character of classic studio hardware: the 1081 Style, 1073 Style, 550b Style, and EQP-1A Style. They are emulations of a sonic character, not exact circuit reproductions, and are named only to describe the sound they aim for. Neve, API, and Pultec are trademarks of their respective owners, and SoundTools is not affiliated with or endorsed by them.

What is the 1081 Style equalizer based on?

It follows the four-band parametric layout of the Neve 1081, a console module from the early 1970s: a treble shelving band, two midrange peaking bands with a Hi-Q option, and a bass shelving band. The original is known for treble boosts that stay smooth rather than harsh, a quality linked to its inductor-based filters and transformer coloration. The 1081 Style preset mirrors that band structure and broad, forward brightness.

What is the 1073 Style equalizer based on?

It follows the three-band layout of the Neve 1073, a 1970 module widely regarded as one of the finest-sounding equalizers ever built: a treble shelf at 12kHz or 16kHz, a single stepped midrange band (360Hz to 7.2kHz), a bass shelf (35Hz to 220Hz), and a steep high-pass filter. Its limited frequency choices are each chosen to be maximally useful, which is why engineers describe its boosts as "musical."

What is the 550b Style equalizer based on?

It follows the four-band proportional-Q design of the API 550b, a 500-series module descended from the 1967 API 550a. Its bands overlap across the spectrum with ±12dB of boost or cut, and the proportional-Q behavior automatically narrows the bandwidth as gain increases, keeping heavy boosts focused instead of muddy. The result is the punchy, forward character heard on a great deal of rock, hip-hop, and pop.

What is the EQP-1A Style equalizer based on?

It follows the passive tube program equalizer designed by Pulse Techniques in the early 1950s. Its signature feature is simultaneous Boost and Attenuate controls on the low band: boosting and cutting the same frequency at once produces an enhanced low end with a tighter, faster-decaying bass response — weight without mud. The EQP-1A Style preset implements the same simultaneous boost/attenuate behavior so you can use the trick yourself.

Does this equalizer upload my audio to a server?

No. All audio processing happens entirely inside your browser using the Web Audio API's BiquadFilterNode, AnalyserNode, and OfflineAudioContext. Your audio files never leave your device — nothing is sent to any server.

How is this different from FabFilter Pro-Q 3?

FabFilter Pro-Q 3 is a professional DAW plugin costing €179, with advanced features including mid/side processing, linear phase mode, dynamic EQ, and a piano-roll display. This equalizer is free, requires no installation, runs entirely in a browser, and is designed for quick tasks — shaping an audio file, applying a vintage-style tone, or learning what EQ actually does. It is not a replacement for Pro-Q 3 in a professional DAW workflow, but it does the common jobs without costing anything.

What audio formats does the online equalizer support?

The equalizer accepts MP3, WAV, FLAC, OGG, AAC, and M4A files. The processed output is downloaded as a WAV file (PCM 16-bit or 32-bit float, 44.1kHz).

Can I use this online equalizer on vocals?

Yes. The equalizer works on any audio content — vocals, music, podcasts, sound effects. For vocals, common techniques include a high-pass filter around 80–100Hz to remove room rumble, a gentle cut around 300–500Hz to reduce muddiness, a presence boost around 2–5kHz for clarity and intelligibility, and an air boost around 10–16kHz for brightness. The 1073 Style and 1081 Style presets are popular starting points for vocal EQ.

Can I hear the equalizer in real time while the audio plays?

Yes. The tool includes a custom preview player. While audio is playing, any adjustment you make — moving a filter node, changing a frequency selector, adjusting gain — updates the processing immediately without stopping or restarting playback. This makes it easy to A/B compare EQ settings by ear.