What it means to merge audio files
Merging audio, sometimes called concatenating, means placing clips end to end so they play as one continuous track. There is no mixing or overlapping involved: when the first clip ends, the next one begins. The result is a single file instead of several.
This tool does it with ffmpeg's concat method. It builds a list of your clips in the order you added them and then encodes the joined audio as an MP3. Because the output is re-encoded, the merged file is always an MP3, whatever formats you started with.
Common reasons to join clips
People merge audio to stitch together a recording that was split into parts, to combine an intro, a main segment, and an outro for a podcast episode, or to assemble several voice notes into a single file for sharing. It is also handy when a recorder saves long sessions in chunks and you want one continuous file afterwards.
It is not a mixer. If you want to play two sounds at the same time, such as speech over music, you need a multitrack editor. Here, clips follow each other and nothing else. If you want to trim a clip before joining it, run it through the Audio Cutter first.
How to merge audio files with this tool
- Drop two or more audio files onto the upload area, or click it to choose them. You can add more files later and they will be appended to the list.
- The files appear in a list in the order you added them. That is the order they will play. To remove one, click the trash icon beside it.
- The Merge audio button stays disabled until at least two files are in the list.
- Click Merge audio. The first use downloads the ffmpeg engine (roughly 30MB). A progress bar shows while it works.
- Play the result in the audio player that appears.
- Click Download. The file is always named
merged.mp3. - Start over clears the list.
The merge runs in your browser. Nothing is uploaded.
Ordering, formats, and what can go wrong
There is no drag-to-reorder control. The order is simply the order you added the files, so if the sequence is wrong, use Start over and add them again in the right order, or remove the offending clip and add it back at the end.
The tool works best when all clips share the same format and similar settings. If the merge fails, it shows a message suggesting you use clips with the same format. Converting everything to one format first with the MP3 Converter is a sensible fix.
Expect a loss of a little quality, since MP3 is lossy and the audio is encoded again. Keep your originals. Large numbers of long clips are held in browser memory, so very big jobs may be slow or fail on weaker devices.