About this tool
Audio merging places multiple files end to end in list order as one continuous track. Sources can differ in format, sample rate, and channels, requiring common decoding and output encoding; differences in volume, noise floor, and rhythm do not disappear automatically at boundaries.
It suits segmented recordings, chapters, and related spoken clips. Use a timeline audio editor for crossfades, simultaneous tracks, beat-accurate placement, or music mixing.
How to use it
Add files in order
Confirm each plays and arrange the list in the intended final sequence.
Choose common output
Set bitrate and compare level and silence at the boundaries.
Listen through the result
Pay particular attention to every join, total duration, and the end of the last segment.
Supported range and limits
- Input
- Several files, which do not have to share a format
- Output
- A single MP3
- Ordering
- List order; never sorted by filename
- Sample rate and channels
- Segments are normalised to one set of parameters before joining; mixed mono and stereo resolves to stereo
- Joins
- Butt-joined end to end with no crossfade; do fades in an audio editor if you need them
- Where it runs
- FFmpeg compiled to WebAssembly in your browser; the files are never uploaded
When you would use it
Joining segmented recordings
Reconnect a meeting split by a device or upload duration limit.
Assembling spoken chapters
Combine numbered course or podcast segments into one sequential file.
Joining a recording made in sessions
Narration or an interview captured across several takes can be merged in order and then processed as one file.
What to know before you start
- Merge means sequential concatenation and does not make sounds play simultaneously.
- Level differences require gain or loudness work first to avoid abrupt joins.
- Re-encoding can remove cover art, tags, and chapter metadata from individual files.
Related concepts
- concatenation
- Placing one audio segment directly after another in time.
- crossfade
- Overlapping a fade-out and fade-in between clips, which differs from a simple join.