How to compress MP3 files
Upload your MP3 file
Drag and drop a file or click to select one. Keep this page open while the file uploads and converts.
Compress the file
NexMedia re-encodes your MP3 file on its own servers at the quality you choose. Processing time depends on the file size and how busy the queue is.
Download the compressed file
When the compression finishes, the download appears on this page. Your compressed file is kept for 2 hours, then deleted.
About MP3
the universal lossy audio format, playable everywhere since the 1990s
MP3 is the audio format that made digital music portable: lossy perceptual encoding at a chosen bitrate, playable by every device and player made since.
MP3 files grow with bitrate and length: an hour at the classic 320 kbps setting is about 140 MB, and many rips still sit at that ceiling even though the source does not need it.
What compressing MP3 does
Compressing an MP3 re-encodes it to a modern codec: AAC and Opus reach the same perceived quality at half the bitrate or less.
An hour of 320 kbps MP3 weighs roughly 140 MB; the same hour in Opus at a quality-matched setting lands near 40–50 MB.
Settings you can change
Before you compress MP3, you can adjust: Audio codec, Rate control, Audio bitrate, Quality (VBR), Sample rate, Channels, Normalize loudness, Trim start, Trim duration, and Keep tags.
Limits
Guests can compress files up to 100 megabytes and run 5 conversions per day; a free account raises this to 500 megabytes and 25 per day; paid plans go up to 100 gigabytes.
Your compressed MP3 file is kept for 2 hours, then deleted.
Compressing MP3: questions and answers
Will compressing MP3 reduce quality?
Re-encoding lossy audio adds a further generation of loss, but modern codecs are transparent at far lower bitrates, so a careful convert sounds the same to nearly every listener.
Can MP3 files be compressed without any loss?
No. MP3 is lossy by design; whatever has been thrown away cannot come back, so compression here means matching how it sounds while storing fewer bits.
Which settings can I change when compressing MP3?
You can adjust: Audio codec, Rate control, Audio bitrate, Quality (VBR), Sample rate, Channels, Normalize loudness, Trim start, Trim duration, and Keep tags. the bitrate control is the whole lever: Opus and AAC hold perceived quality at 96–128 kbps where MP3 needed 256 kbps
How much smaller will my MP3 file get?
Moving from a 320 kbps MP3 to Opus or AAC at matched quality typically cuts the size by 60–70%.
How large a MP3 file can I compress for free?
Guests can compress files up to 100 megabytes and run 5 conversions per day; a free account raises this to 500 megabytes and 25 per day; paid plans go up to 100 gigabytes. Your compressed file is kept for 2 hours, then deleted.