Audio Joiner: Merge MP3 & Audio Files
This audio joiner merges two or more files into one track: MP3, WAV, M4A, FLAC and OGG can be mixed in the same job. Drag the files into order, choose back-to-back, a gap of silence or a smooth crossfade, and let it even out loudness so no track jumps out. Everything happens in your browser, so your recordings are never uploaded.
- Runs on your device
- Web Audio
- WebCodecs · GPU
- Works offline
Updated
Drop your audio files here
How to merge audio files
Step 1: Drop two or more audio files on the box above.
Step 2: Drag them into the order you want them played.
Step 3: Set a Crossfade for music, or a Gap between tracks for speech, and keep Match loudness on.
Step 4: Choose the format under Save as, press Join and download the single file.
Good to know
Settings explained
- Gap between tracks
- Silence between tracks (only without a crossfade).
- Match loudness
- Evens out volume differences between tracks.
Formats
Combines 2 or more files into one result.
How it runs
- Web Audio
- Audio is processed with the browser’s built-in Web Audio engine, sample-accurate and fast.
- Hardware video engine
- Video is decoded and encoded by your device’s media hardware through WebCodecs — usually several times faster than real time.
Join settings explained
Three choices shape how the tracks meet. Back to back (no crossfade, no gap) suits chapters of one recording. A gap gives each clip room, useful for language lessons or separate voice notes. A crossfade overlaps the end of one track with the start of the next, the way a radio DJ blends songs.
| Setting | Range (default) | What it does |
|---|---|---|
| Crossfade | 0–10 s (0) | Equal-power blend between neighbours, never longer than 45% of either track |
| Gap between tracks | 0–5 s (0) | Silence inserted between tracks; only used when Crossfade is 0 |
| Match loudness | On | Measures each track (LUFS) and brings them all to the median level, by up to 15 dB |
| Save as | MP3, M4A, WAV, FLAC (MP3) | Format of the joined file; WAV and FLAC are lossless |
| Bitrate | 64–320 kbps (192) | For MP3 and M4A only, under Advanced settings |
How do I combine two MP3 files into one?
Drop both MP3s on this page, check they are in the right order (drag to swap), keep Save as on MP3 and press Join. The result is one continuous MP3 named after the first file with “-joined” added. To combine MP3 files with music, a 2–4 second crossfade hides the change of song; for speech, a 0.5–1 second gap sounds natural.
The same steps work for any number of files, from two voice notes to a 30-track mix.
Can I join audio files in different formats?
Yes. Every file is decoded first, so an MP3 interview, a WAV jingle and an M4A voice memo can go into one job. They are brought to a common format before joining: the highest sample rate among them, up to 48 kHz, and stereo if any of them is stereo (mono tracks then play in both speakers). The joined file is then written once in the format you choose.
Will merging re-encode my audio?
Yes, once. To crossfade, match loudness or mix formats, the joiner has to work on decoded audio, so the result is encoded again at the end. Choose WAV or FLAC under Save as for a lossless result. For MP3 or M4A output, a bitrate at or above your sources (192 kbps by default) keeps the extra loss inaudible.
Why use this MP3 joiner
- Loudness matching. Quiet and loud recordings come out at one level, measured the way streaming services measure it (ITU-R BS.1770).
- Real crossfades. Equal-power curves keep the volume steady through the blend instead of dipping in the middle.
- Clear errors. If one file is damaged, the joiner names it, so you can remove it and run again.
- Private and free. No upload, no account, no watermark, no limit on the number or length of files.
Merge audio files on iPhone, Android or a computer
Open this page in Safari, Chrome, Edge or Firefox. On a phone, tap the drop zone and select several files at once from Files, Downloads or your recorder folder, then drag them into order with your finger. On a computer, drag the files in from File Explorer or Finder. The joined file is saved to Downloads. Very long joins, such as a whole audiobook, are easiest on a computer with more memory.
Tips & troubleshooting
Trim silence or mistakes from each part with the MP3 cutter before joining.
Joined a long podcast and want it tighter? Run the result through remove silence from audio.
Putting video clips together instead? Use merge videos, which handles picture and sound.
For a final loudness target such as −16 LUFS for podcasts, follow up with normalize audio.
Audio Joiner FAQ
How do I merge MP3 files?
Drop the MP3s on this page, drag them into order, pick a crossfade or gap if you want one, and press Join. You get one MP3 containing all of them in sequence.
How do I add a crossfade between songs?
Move the Crossfade slider to 2–5 seconds before pressing Join. The end of each song fades out while the next fades in, using equal-power curves so the volume stays even. Very short tracks get a shorter crossfade automatically.
Can I merge audio files on iPhone or Android without an app?
Yes. Open the page in Safari or Chrome, tap the drop zone, select the files, put them in order and press Join. The joined file is saved to Downloads, with nothing to install.
Does Match loudness change my audio?
Only its overall level. Each track is measured in LUFS and turned up or down, by at most 15 dB, to the median level of the set. Tracks that are already even are left alone, and the result card says which happened.
Is this audio joiner safe?
Yes. The files are read and joined by your own browser, so they are never uploaded or stored anywhere else. Once the page has loaded it also works offline.