Merge MP3 and Audio Files Into One

Combine several audio files into a single MP3

Merging MP3 files (also called joining, combining or concatenating audio files) comes in handy in many situations: putting back together the tracks of an album or an audiobook split into chapters, preparing a non-stop playlist for a party, a workout class or a wedding, assembling the parts of a podcast or an interview, or stitching together several takes of the same recording. The tool accepts as many files as you like, in different formats (an MP3, an iPhone M4A, a WAV from a voice recorder…), converts them to the same format, then joins them in the order you chose. The result is a single 192 kbps MP3 that plays everywhere, or an M4A (AAC), handy on iPhone and Mac. The tags of the original files (title, artist, cover art) are not copied, since the final file mixes several tracks.

Join WhatsApp voice messages into one audio file

WhatsApp voice messages are Opus files, with the .opus or .ogg extension, and a long message is often split into several voice notes. To keep them together or forward them in one go, export them from the chat (on Android: long-press the voice note, then Share; on iPhone: long-press, Forward, then the share icon, or use "Export Chat" with media), then add them all here. Put them in the order they were sent, add a short one-second silence between them if you want to tell the messages apart, and download a single MP3 that any phone, computer or car stereo can play. Voice messages from Messenger, Telegram or phone voice recorders (M4A, AMR, 3GP) work the same way.

Crossfade or silence: getting the transition right

With no transition, the tracks play back to back, exactly as in the original files: the right choice for an audiobook or a recording split into parts. A crossfade fades out the end of one track while the next one fades in: ideal for a music mix, with no gap or abrupt cut. Two to three seconds is usually enough; five seconds gives a DJ-style blend. Since the tracks overlap, the total length shrinks by the crossfade length at each transition, and a crossfade can't be longer than half of the shortest track. Silence, on the other hand, adds a gap between two files, from 0.5 to 5 seconds: useful to separate messages, oral exam questions or practice tracks. The total length shown takes these settings into account.

Merge audio files without Audacity or any software

Audacity, VLC or a video editor can merge MP3 files, but you have to install them and learn how to use them. Here, everything happens in your browser, on a Windows PC, Mac, Chromebook, iPhone or Android: no installation, no account, no cap on the number of files. Your files are not sent to a server: they are put together on your device by FFmpeg, an audio and video engine downloaded only once (about 30 MB). For an hour of music, expect a few dozen seconds on a recent computer. If you first want to remove part of a track, use "MP3 Cutter"; to join videos rather than sounds, go to "Merge Videos".