Free Online Audio Joiner
Concatenate multiple audio files into a single MP3 — drag to reorder, preview, and download. Works with MP3, WAV, FLAC, AAC, OGG, M4A. Runs entirely in your browser via WebAssembly.
Features
Multi-Format, One Output
Mix MP3, WAV, FLAC, AAC, OGG and M4A in one batch — the joiner normalizes each track and stitches them into a single MP3 without format fights.
Drag to Reorder
Upload in any order, then drag tracks up or down to set the sequence. The final MP3 follows your list exactly.
Auto Sample-Rate Normalization
Every input is resampled to 44.1 kHz stereo before concat — no pops, clicks or speed issues when joining tracks recorded at different rates.
Gapless Concat
Files are joined via the concat demuxer so there is no silent gap, no crossfade, no surprise — just the tracks played back-to-back.
Quality Output, Small Files
The joined MP3 is encoded with LAME VBR quality 2 — transparent for voice and music, and a fraction of the size of an uncompressed file.
Voice & Music-Safe
LAME VBR allocates more bits to complex sections, keeping speech natural and music detailed while silence stays compact.
Fast, Seconds-Scale
Joining 10 tracks of a few minutes each typically takes under a minute. Audio-only processing is far faster than video.
Instant Playback
Output MP3 has the header up front so it plays immediately in browsers, players and podcast apps — no re-encoding on the player side.
100% Private & Free
Your audio never leaves your device. The joiner runs in your browser tab via WebAssembly — no server, no upload, no tracking.
Zero Server Upload
Files are read, joined and downloaded entirely on your own machine. We never see the tracks or the joined output.
No Watermark
Clean output — no audio intro, no brand tag, no metadata injected. Your audio, untouched.
Works Everywhere
Any modern browser on any device — Chrome, Firefox, Safari, Edge, desktop or mobile.
FAQ'S
Frequently Asked Questions
Ask us anything!
Join Audio Files Into One MP3
Free, private, and instant. No signup, no upload, no watermark — drop a handful of tracks, set the order, download a clean joined MP3.