Audio Joiner
Join audio files online with a free browser-based audio joiner. Set track order and download one MP3; your files stay on your device while merging.
Free browser audio tool
Merge Audio Files Online
Join two or more audio tracks into one MP3. Add your files, arrange the playback order with the up and down controls, then merge and download the combined track.
How to join audio files
- Select at least two audio files. The media engine loads the first time you add files and must finish loading before you can merge.
- Use the up and down buttons beside each file to set the track order. The list runs from first track to last.
- Choose Merge Audio Files. When processing finishes, the joined MP3 downloads to your device.
Input formats, output, and limits
The file picker accepts audio files. Actual input support depends on the audio codec available in the browser media engine, so not every file labeled as audio will necessarily decode. MP3 and WAV are good formats to try first; if a file fails, convert it to a common format with the Audio Converter and try again.
The joined output is always MP3. The tool decodes and re-encodes the selected tracks, so the output format and file size can differ from the inputs and lossy sources may lose some audio quality. Crossfade and per-track trimming are not available in this joiner; use the Audio Trimmer before joining if you need to cut a track.
Each audio file can be up to about 1.07 GB. There is no fixed total batch-size cap, but large or long batches may be slow or use more memory than your device has available. Try merging fewer files at a time if processing fails.
A quick example
To put a WAV introduction before an MP3 recording, add both files, move the introduction above the recording, and merge. The result downloads as one MP3 track in that order.
How file processing works
Audio is processed in your browser with FFmpeg WebAssembly. The selected audio files are written to the browser-based media engine and are not uploaded by the merge operation. On first use, the page downloads FFmpeg core files from jsDelivr; this downloads the processing software, not your audio.
The engine decodes the inputs and encodes the joined result as MP3. Keep the source files if you need a lossless workflow or want to compare the result, since this tool does not export a lossless format.
Frequently asked questions
Can I change the order of the audio files?
Yes. Use the up and down buttons beside each selected file. The first item plays first in the merged output.
What format will the joined file use?
The download is an MP3, regardless of the input file extensions.
Are my audio files uploaded?
No. The merge operation processes the selected files in your browser. FFmpeg software is fetched from jsDelivr when the engine loads.
Can I add a crossfade between tracks?
No. Tracks are joined in sequence without a crossfade. Trim the files before joining if you need to change their start or end points.
Is there a maximum file size?
Each file can be up to about 1.07 GB. Your device’s available memory and processing capacity determine the practical total batch size.