Audio Merger: Join or Overlap Audio Files
Put MP3, WAV, M4A and other audio files end to end on one timeline, or stack them to play together, and balance the levels. The free export is an MP4 video; plain audio files come with paid plans.
Audio Merger: Join or Overlap Audio Files Features
Echowave is used by thousands of businesses around the world
To merge audio files, open the EchoWave editor, add your tracks, drag them into order on one timeline track, trim the edges and export. There is no separate merge button: merging is done on the editor timeline, where you can also layer tracks, set each clip's volume and add fades.
What you download: the free export is an MP4 video with a small EchoWave badge and a four-second end card. Audio-only downloads are on paid plans: MP3 and M4A on Creator, WAV and FLAC on Pro.
What goes in: nearly any audio format. MP3, WAV, M4A, AAC, OGG, Opus and FLAC work, and AIFF, WMA and several rarer formats are converted for you. You can mix formats in one project. We do not publish a total size limit, and very long files take longer to upload and render.
How to merge audio files in EchoWave
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1. Upload your audio files
Open the editor and add every track you want to join, using the upload button or by dragging the files in. Each file becomes a clip on the timeline.
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2. Put the clips in order
Drag the clips onto one track so they sit end to end. Magnetic snapping pulls each clip flush against its neighbour. Trim the edges, set each clip's volume, and add Fade in and Fade out where two tracks meet.
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3. Export, then get the audio file
Preview the join, then export. Free: you get an MP4 video. Creator: choose MP3 or M4A in Export; Pro adds WAV and FLAC. The first download from the editor asks for your email address.
How creators use EchoWave in real projects
Join audio files or overlap them
Joining puts clips end to end: the first plays, then the second starts. Use it for an episode built from an intro, an interview and an outro, for chapters of an audiobook, or for songs in a set. Keep every clip on one track and magnetic snapping closes the gaps.
Overlapping plays clips at the same time, which is what an audio overlapper does. Use it for a voice over a music bed, a sound effect under dialogue, or two songs mashed together. To overlap two audio files:
- Put the first file on one track.
- Drop the second file on the track below it, so the two are stacked.
- Slide the second clip until it starts where you want.
- Set each clip's volume so the important one stays in front, then preview and export.
For a crossfade between two songs, overlap the end of one with the start of the next on two tracks, then add a Fade out to the first clip and a Fade in to the second. To shorten the pieces first, use the audio trimmer. When the merged track should become a video for YouTube or social, add a music visualizer in the same project.
Get a clean merge
- Start from good files. The export is rendered again as a new file, so use WAV or a high-bitrate MP3 where you can.
- Trim dead air first. Cut silence from the start and end of each clip before you snap it into place so the gaps do not add up.
- Match the loudness. If one clip is much quieter, change its volume so listeners do not reach for the dial at the join. The editor can also normalise loudness to a target of -14, -16, -18 or -23 LUFS, and balance all clips at once.
- Fade at the seam. A short fade out and fade in hides a click or a change in room tone.
- Listen to the whole preview. Check every join before you export, because each free export adds a four-second end card at the end.
About the EchoWave team
EchoWave is a browser-based video and audio editor built by Lemon Vault LLC since 2018. The people who build the editor write these guides and test every step in the production app before publishing.
Audio merger FAQ
How do I merge two audio files into one?
Open the EchoWave editor, add both files, drag them onto one track so they sit end to end, then export. The free export is an MP4 video. On a Creator plan or higher, choose MP3 or M4A in Export instead.
How do I overlap two audio files so they play at the same time?
Put each file on its own track, stacked one above the other, and slide the second clip to the moment it should start. Set each clip's volume so the voice or main track stays clear, then preview. Both tracks are mixed into one soundtrack when you export.
Can I download the merged file as an MP3 for free?
Not directly. The free export is an MP4 with a small badge and a four-second end card. Exporting MP3 or M4A straight from the editor needs a Creator plan, and WAV or FLAC needs Pro.
Can I join MP3 and WAV files together?
Yes. MP3, WAV, M4A, AAC, OGG, Opus and FLAC all work, and rarer formats such as AIFF and WMA are converted on import. Mixed formats sit side by side on the same timeline without converting anything first, and you choose one output format when you export. You can also drop in an MP4 or MOV and use only its sound.
How many audio files can I merge at once?
We found no cap on the number of clips on the timeline, and we do not publish a total size limit. The editor is built for long multi-clip projects such as full podcast episodes and chaptered audiobooks. Large files take longer to upload and render, so a very long recording waits longer than a short one.
How do I add a crossfade between songs?
Place the two songs on separate tracks so the end of the first overlaps the start of the second. Then add a Fade out to the first clip and a Fade in to the second and listen to the preview. EchoWave has no automatic crossfade button, so the overlap length sets how long the blend lasts.
Will merging reduce the audio quality?
The export is rendered as a new file, so start from the best copies you have, such as WAV or a high-bitrate MP3. Joining clips does not change the sound of each clip beyond that one re-encode. For a lossless result, export WAV or FLAC on the Pro plan.
Do I need to download software to merge audio?
No. EchoWave runs in Chrome, Edge, Firefox and Safari on Mac, Windows, Linux and Chromebooks. The first download from the editor asks for an email address, which creates a free account. Nothing is installed on your computer at any step.
Can I turn the merged audio into a video?
Yes, in the same project. Add a music visualizer, a waveform or a still image over the joined track and export an MP4 for YouTube, Facebook or Instagram. If the audio has speech, captions can be generated from it and styled on screen.
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