How to merge MP3 files into one

Joining audio files is one of those jobs that shouldn’t need software: a podcast intro and episode, chapters of an audiobook, a set of songs for a workout, or voice notes you want in one file. The Glowtrack Studio audio joiner does it in your browser, in any order, with smooth transitions.

Open the free audio joiner →

Choosing a transition

Crossfade (music): the end of one track fades out while the next fades in. Three to six seconds sounds like a DJ mix.
Gap (speech): a short silence between files, such as one second between podcast segments or chapters.
Neither: files play back to back — useful for audio that was split into parts and should sound continuous.

Getting it right

Even out the volume: files recorded at different levels are matched so nothing jumps out.
Trim each file: cut silence or chatter off the start and end before joining.
Order by name: for numbered chapters, “Sort by name” puts 1, 2 … 10 in the right order.

Step by step

Open the Glowtrack Studio audio joiner and drop in all your files at once — MP3, WAV, M4A, FLAC or OGG.
Drag the ⋮⋮ handles (or use the arrows) to put them in order, and drag the edges of each waveform to trim.
Set a crossfade for music or a gap for speech, and leave “Even out volume” on.
Press Play joined to check the transitions, then choose MP3 and press Join & save.

Open the free audio joiner →

Questions

Is there a limit on files or length?

No fixed limit. Very long results (several hours) use a lot of memory, so a computer handles them better than a phone.

Can I cut a section out of a file?

Yes — use the audio cutter to remove part of a single file, then join the results if you need to.

Are my files uploaded?

No. Everything happens in your browser on your own device.