What format is the output?

SpeakAndRecord's audio merger combines multiple audio files into a single seamless track directly in your browser. Upload any number of MP3, WAV, OGG, or WebM files, then drag the items to set the playback order. When you click Merge, each file is decoded using the Web Audio API and concatenated into a single AudioBuffer, which is then exported as a lossless WAV file.

Common use cases include joining podcast segments, combining voice memos, assembling music loops, merging interview clips, or creating a compilation from multiple recordings. The entire process is private — no files are uploaded to any server.

How many files can I merge?

There is no hard limit set by the tool. Practically, very large files (several hours total) may use significant RAM — the browser will warn you if it runs out of memory.

Does the order matter?

Yes. Files are merged in the order shown in the list. Drag items up or down to reorder before merging.

What is the output format?

WAV (PCM 16-bit). It's lossless and universally compatible. If you need MP3, you can convert the WAV using Audacity, FFmpeg, or any free converter.

How to merge audio files online into one track

This guide covers the practical side: preparing your files, checking the result, and knowing what size to expect.

Step by step

Rename your files so you recognize them, for example 01-intro, 02-interview, 03-outro.
Drop the files into the box, or use the browse link to select them.
Look at the list from top to bottom. That is the playback order.
Drag any item that is in the wrong place.
Remove a wrong file, or use Clear all to start again.
Click Merge & Download WAV and wait for processing to finish.
Play the merged audio in the player before you download it. Listen to each join point.

A worked example

Say you have three clips: a 45-second intro, a 3 minute 30 second interview (210 seconds) and a 15-second outro.

Total length: 45 + 210 + 15 = 270 seconds, or 4:30.
WAV at 16-bit, 44.1 kHz, stereo uses 44,100 × 2 bytes × 2 channels = 176,400 bytes per second.
Estimated size: 270 × 176,400 = 47,628,000 bytes, about 47.6 MB.

If the audio is mono, the size is half: about 23.8 MB. The exact sample rate of your output may differ, so treat this as an estimate. It helps you judge whether your device can handle a long merge.

Practical tips

Trim first. Silence at the start or end of a file stays in the merge. Cut it with the Audio Cutter before joining if you want tight transitions.
Match the volume. Clips recorded on different devices can differ in loudness. Listen to the joins and fix the quiet clip in an editor if needed.
Test with short clips. For a long project, merge two short files first to confirm the order and result.
Keep the originals. Do not delete your source files until you have listened to the whole merged track.
Merge in stages. If a very large batch is slow, merge it in groups, then merge the results.

Common uses

Joining a podcast intro, main part and outro.
Combining voice memos from one meeting into one file.
Putting recorded lecture parts in one sequence for easier listening.
Assembling short sound clips or loops into a longer track.

Questions

Why is the merged file much bigger than my MP3 files?

MP3 is compressed and WAV is not. The same sound takes more space as WAV. In the example above, 4.5 minutes of stereo audio comes to about 47.6 MB.

Will I hear a gap or a click between two files?

The files are placed one after another with no added pause and no crossfade. A gap you hear usually comes from silence already in the source file. A click can come from a clip that was cut mid-sound. Trim the file or re-cut it at a quieter point.

Can I use the merger on my phone?

You can try, as long as your browser lets you select audio files. Phones usually have less memory than computers, so keep the total length short. If the merge fails, split the job into smaller groups.