Why your video is never uploaded
Most online converters send your whole video to their server, convert it there and send the result back. That takes time on a slow connection, and it means a copy of your file sits on someone else's computer.
This page works differently. When you press Convert, your browser reads the sound from the video and writes the MP3 itself, using your device's own processor. Nothing is sent anywhere, so a family video or a private recording stays exactly where it was.
It also means the speed depends on your device rather than your connection. A short clip converts in a few seconds on most phones, and a computer handles long videos comfortably.
Which MP3 quality to choose
The number is the bitrate: how much data each second of sound may use. Higher numbers keep more detail and make larger files.
128 kbps is enough for speech: lectures, interviews, voice notes. A one-hour recording comes to about 58 MB.
192 kbps is the sensible default. Music sounds clean on phone speakers and earphones, and a four-minute song is around 6 MB.
320 kbps is the highest MP3 setting and worth it for music you will play on good speakers. It cannot add detail the video never had, so for a phone recording of a noisy room it only makes the file bigger.
A video file or an Instagram link?
This tool is for videos you already have: something you filmed, a screen recording, a clip someone sent you. Choose the file and the sound comes out as an MP3.
If what you have is a link to an Instagram reel or post, there is no need to download the video first. The Instagram audio downloader takes the link and saves the sound in one step.
Where your MP3 is saved
Your browser decides, and it depends on the device. On iPhone and iPad, look in the Files app under Downloads. On Android, the MP3 goes to the Downloads folder and most music players find it on their own. On a computer it lands in your usual downloads folder.
The file is named after your video, so a clip called holiday.mp4 becomes holiday.mp3.
MP3 encoding uses the open-source LAME encoder through lamejs, used unmodified under the LGPL.