Join Audio Files Online

Combine several tracks into one audio file

Audio often arrives in pieces: separate voice memos, chapters of an audiobook, individual song sections, podcast segments or a sequence of sound effects. Playing or sharing them one after another is awkward when they really belong together. This tool joins two or more audio files into a single continuous track that plays end to end, so you can hand over one clean file instead of a folder full of clips. It is useful for assembling rough podcast episodes, stitching recorded notes, building a looping background or simply merging downloads into one playlist file.

The whole process runs in your browser. Each selected file is written into ffmpeg.wasm's temporary file system, the tracks are re-encoded through a concat filter and a single output file is produced locally. Nothing is uploaded, there is no account and no server keeps a copy. That keeps private recordings, draft episodes and unreleased music on your own device while you put the pieces together.

Order, formats and re-encoding

Files are joined in the order they appear after you pick or drop them, so arrange them in the sequence you want before joining. Because the inputs are re-encoded rather than copied, you can mix different source formats, sample rates and bitrates and still get a consistent result. Choose MP3 for a small, widely compatible file, M4A for efficient AAC audio that suits phones and modern apps, or WAV when you need an uncompressed track to keep editing. The concat filter normalizes the streams so the boundaries between clips play back smoothly.

Quality and memory notes

Joining many long files uses memory because every input and the output are handled locally. Shorter clips and a reasonable number of files work best, while very long high-bitrate recordings may take time or run into browser memory limits. If you plan to keep editing later, WAV avoids stacking another lossy generation on top of compressed sources. The first join may pause while the WebAssembly engine downloads, but later joins in the same tab start immediately. Always keep your original files until you have listened to the combined track from start to finish.