QuadEqualizer is a free, browser-based 4-band audio equalizer. Load an MP3, WAV, M4A, or OGG file and shape its low, low-mid, high-mid, and high frequencies in real time, with a live spectrum display and a set of advanced controls (bypass, limiter, mono downmix, rumble filter, and more) for finer control over the sound.
It runs entirely on the Web Audio API built into your browser. There is nothing to install, no account to create, and no file is ever uploaded to a server — your audio stays on your device from start to finish.
Most "online equalizer" tools either require an upload, a signup, or a subscription. QuadEqualizer was built to be the opposite: something you can open, use immediately, and close without leaving a trace — no account, no server-side processing, no cost.
QuadEqualizer is an independently built and maintained tool. It is not affiliated with, endorsed by, or sponsored by any audio hardware manufacturer, streaming service, or software brand. Any resemblance to hardware equalizer units in the visual design is purely aesthetic.
Have a question, a bug to report, or an idea for the tool? See the Contact page.