Audio Joiner

Your clips appear as a numbered list next to the preview. Drag a row to move it, use its up and down arrows, or focus it and press the arrow keys. Sort by name puts numbered files such as chapter-1 to chapter-10 in the right order, Sort by size groups short and long clips, and Reset returns to the order you added them in.

The numbers in the list match the numbered bands on the timeline, so you can see where each clip lands in the joined file. Changing the order updates the preview straight away.

Between clips decides how one clip meets the next. Back to back joins them with no pause. A silence gap adds a pause of 0.1 to 5 seconds, which suits speech: chapters, interview answers and voice notes read more clearly with a short breath between them.

A crossfade overlaps the end of one clip with the start of the next for 0.1 to 5 seconds, which suits music and ambient sound. It uses an equal-power curve, so the volume does not dip in the middle of the overlap, and it is never longer than half of the shorter clip, so a short clip is not swallowed by its neighbours.

The preview is the joined audio itself, not a list of separate files. Each clip is a numbered band on one timeline, with a waveform lane per channel, a level meter, frequency bars and a scrolling spectrum while it plays, and crossfades show where neighbouring bands overlap.

Click a band or a list row to select that clip. Play then covers the selected clip together with the transitions into and out of it, Loop repeats it, and you can zoom in on a joint to check it. After you join, the whole result plays from start to finish, so you hear exactly what you are about to download.

You can combine any audio your browser can decode, such as an MP3 voice note, a WAV recording and an M4A from a phone, in one join. Clips recorded at different sample rates are aligned to the highest rate in the list, and mono clips are widened to stereo when other clips are stereo, so nothing plays too fast, too slow or on one side only.

The export starts from your first clip's format and quality. WAV and FLAC joins are lossless; MP3, M4A, AAC and OGG are encoded once when you save, so choose WAV or FLAC if the file will be edited further, and MP3 or M4A when it is ready to share. M4A, AAC and OGG are offered where your browser provides those encoders.

The Audio Joiner keeps each clip whole and does not change its volume. To cut a clip down first, use the Audio Trimmer. If one clip is much louder or quieter than the rest, run it through the Audio Normalizer before joining.

For cuts inside a clip, fades or effects, use the Audio Editor. To change a file's format without joining anything, use the Audio Converter, and to make several short clips from one long recording, use the Podcast Clip Maker.