Online Audio File Effects
These three tools change an audio file you already have. You pick a file, set one parameter, and download the result as a WAV. The file is decoded and processed inside this tab with the Web Audio API, so it is never uploaded, and nothing you do here is kept on a server.
Everything runs in your browser. No audio is ever uploaded.
Tools in this category
What people use these for
The common jobs: a recording that is too quiet for a podcast feed, a backing track that sits a semitone away from the singer, a language lesson that runs too fast to follow, a voice memo that clips on the loud words, and a file that has to hit a platform loudness target before it goes anywhere. Each one is a single parameter and a single download.
How to choose
Pick by what you want to keep. The volume adjuster changes loudness and leaves pitch and length alone; it can apply a fixed gain in decibels, normalize to a peak or RMS target, or hit a LUFS loudness target with presets for streaming, podcast and broadcast. The pitch shifter moves the pitch by up to twelve semitones and keeps the length. The time stretcher changes the speed and keeps the pitch.
All three give you an A/B comparison against the original before you download, which is the fastest way to catch a setting that went too far. The volume adjuster also reports the measured peak, true peak, RMS and LUFS of the file you loaded, so you can see what you started with instead of guessing at it.
Before you trust the result
Two limits are worth knowing. Everything is processed in memory, so a long file needs a lot of it and a very large file is refused rather than allowed to freeze the tab. And the output is always WAV: if you feed in a compressed MP3, the download will be considerably larger than the file you picked, because the encoding is not put back.