Audio Merger
Concatenate two or more audio clips into one file, with optional crossfade between segments.
What is Audio Merger?
A joiner for audio segments: stitching an interview together, combining music tracks, or assembling multiple takes into one file.
How it works
Every input is resampled to a common 48 kHz stereo layout so mismatched sources line up, then the clips are joined with ffmpeg's concat filter — or chained with acrossfade when you set a crossfade.
- Load your file. Drag a file onto the drop zone or pick one from your device. It is read locally by the browser and never uploaded.
- Set the options. Adjust the handles, format, quality or threshold controls — the preview updates as you change them.
- Process and download. Run the tool, then download the result. Compare the reported before/after size for compressors and converters.
Examples
A 42 MB podcast episode → 9 MB MP3
Trim the intro, normalise to −16 LUFS, and export at 96 kbps mono — a typical interview lands around a fifth of the original size.
A phone video with the wrong orientation
Rotate 90° and the width/height swap in the output, so it plays upright in every player instead of relying on metadata flags.
Common mistakes
Expecting instant encoders
Video encoding runs in single-threaded WebAssembly, so a clip takes roughly its own length (or a little longer) to re-encode. Stream-copy operations are near-instant by comparison.
Re-encoding when a copy would do
Trimming, removing audio and joining same-codec clips can copy streams without re-encoding — pick the copy option when it is offered to avoid any quality loss.
Ignoring the first-load download
The media engine is about 31 MB and is fetched on first use, then cached. The first conversion on a connection is slower than every later one.
Frequently asked questions
Can I mix formats in one merge?
Yes. MP3, WAV, M4A and OGG clips can be combined; each is normalised to a shared sample rate and channel layout before joining.
How does crossfade work?
Each pair of clips overlaps by the number of seconds you choose, so the end of one dissolves into the start of the next instead of cutting abruptly.
Is joining lossless?
Not by default — the clips are re-encoded to one output format. Export WAV or FLAC if you want a lossless master to edit further.