Online audio codec tester

project , published by Maarten Tromp, 304 words

Welcome to the online audio codec tester. Upload your own music and get a test file with alternating sections of original and compressed audio. Can you hear the difference?

Background information on the project can be found here.

Input file

Select the music you would like to use for the test. For best results use a high quality audio file.

Codec and bitrate

Codec will determine which compression algorithm will be used. MP3 is an older and probably the best known codec. Opus is a modern higher quality codec.

Bitrate means the amount of compression that will be applied. The lower the bitrate, the lower the resulting audio quality. Results are codec specific (i.e. a 64k MP3 will sound different from 64k Opus).

Constant bitrate is mostly used for older codecs. Variable bitrate attempts a more constant audio quality. Most modern codecs support both, but use VBR by default.

If you don't know where to start, try MP3 constant bitrate at 64k. If you hear a difference, go higher, if you don't hear a difference, go lower.

Section length

Select how long each version should be played before switching.


By clicking the button below the webserver will create a test file for you and offer it for download. All that's left is to listen to the test file and find out if you can hear the difference between both versions.