Audio Merger

About this tool

Select two audio files and the tool joins them end to end, with File 1 first and File 2 second, into a single MP3. It uses ffmpeg's concat filter in WebAssembly, so the merge happens in your browser and neither file is uploaded. Because the audio is decoded and re-encoded, the result is lossy even if both inputs were lossless, and the two files can have different formats or sample rates. It joins exactly two files per run; to combine more, merge the result with another file. The first run downloads the ffmpeg engine (about 25 MB) from this site, which can take from a few seconds to a minute on a slow connection; later runs on the same page reuse it.

How to use it

1. Choose File 1, the part that should play first.
2. Choose File 2, the part that follows.
3. Press Process and wait for the progress bar.
4. Preview the joined audio and press Download.

Common problems

It says to choose both files

Both pickers must have a file before Process works.

I need to merge three or more files

Only two inputs are supported per run. Merge two, then merge that result with the next file.

Processing failed

One of the files may not be readable audio. Try converting it to MP3 first with the Audio Converter.