Convert MP4 to MP3, Compress Video and Cut MP3 Without Uploading Files
Free browser tools to extract audio from video, convert MOV or WebM to MP4, compress a video for WhatsApp and cut an MP3 clip, all done on your device with no upload.
Most online media converters upload your video to a server, which is slow and a risk for private recordings. The tools below run inside your browser using a WebAssembly build of FFmpeg, so the file never leaves your device.
Quick answer
| Job | Tool |
|---|---|
| Get the sound of an MP4 as MP3 | MP4 to MP3 |
| Audio from any video format | Video to MP3 |
| M4A, AAC, OGG, FLAC to MP3 | Audio to MP3 |
| Shrink a large WAV | WAV to MP3 |
| MP3 to uncompressed WAV | MP3 to WAV |
| Cut a ringtone or clip | MP3 Cutter |
| Make a video smaller | Compress Video |
| iPhone video to MP4 | MOV to MP4 |
| Screen recording to MP4 | WebM to MP4 |
How it works
Open a tool, add the file and press convert. The first time, your browser downloads the converter engine (about 30 MB) and keeps it for next time. After that, conversion starts at once and runs on your own processor.
Choosing quality
For speech, lectures and interviews, 96 to 128 kbps MP3 is enough and keeps the file small. For music pick 192 kbps or higher. When compressing video, the balanced setting with a maximum width of 1280 pixels is a good start; lower it to 854 or 640 for chat apps with tight size limits.
Limits
Files up to about 400 MB work on most computers. Phones can handle shorter clips. Very long videos take minutes because everything runs locally. Some rare codecs are not supported.
Privacy
Your recordings are not uploaded. This matters for meetings, family videos and anything you would not want on someone else's server.
Frequently asked questions
Why is the first conversion slower? The engine downloads once. Later runs are faster.
Can I cut an MP3 without re-encoding? The cutter re-encodes at your chosen bitrate, which keeps the clip compatible with every player.
Does it work offline? After the page and engine are cached, conversions can run without a connection.
