Audio Joiner
Merge several tracks into one file, with an adjustable gap and automatic sample-rate matching.
Join Several Tracks Into One File
Joining audio comes up constantly: a podcast intro in front of an episode, three voice memos that belong together, a set of takes that should play as one piece. The operation is trivial, but the usual route runs the files through someone else’s server first.
This joiner decodes every track in your browser, resamples them to a common rate, and writes one continuous WAV. The resampling matters more than it sounds — two files recorded at 44.1 kHz and 48 kHz spliced together without it will play the second half at the wrong speed and pitch.
Key features
- Order you control — each track shows its length, channels and sample rate, and the arrows move it up or down before you join.
- Automatic rate matching — mixed sample rates are converted to the highest one present, so nothing plays back fast or slow.
- Mono and stereo mixed freely — a mono clip dropped between two stereo tracks is widened rather than knocking the file out of alignment.
- Adjustable gap — insert up to five seconds of silence between tracks, which is what keeps spoken segments from running together.
- Preview the whole join — play the combined result before downloading it.
This tool runs entirely inside your browser using native Web APIs. Your files and text are never uploaded to a server, never logged and never shared with third parties.
How to use: Audio Joiner
- Add two or more files
Drop them all at once or add them in batches. Each one is decoded as it arrives and listed with its details. - Put them in order
Use the arrows to arrange the sequence. The tracks are joined top to bottom, exactly as shown. - Set the gap
Leave it at zero for a seamless join, or add silence between tracks to give spoken segments room to breathe. - Join and download
Press Join and download. The combined WAV is assembled in memory and saved straight to your device.
Technical specifications
| Processing location | Entirely in your browser — no server round trip |
|---|---|
| Data uploaded | None. Files and text never leave your device |
| Price | Free — no account, no trial, no usage cap |
| Category | Audio |
| Works offline | Yes, once the page has loaded |
| Browser support | Chrome 90+, Edge 90+, Firefox 90+, Safari 15+ |
| Interface languages | English, 中文, हिन्दी, Español, العربية |
Frequently asked questions
Can I join files of different formats?
Yes. An MP3, a WAV and an M4A can be joined in one go — each is decoded by the browser first, so the original container stops mattering once it is in memory.
What happens with different sample rates?
Everything is resampled to the highest rate present before joining. Without that step the second file would play at the wrong speed, which is the classic failure of naive audio concatenation.
Is there a limit on how many tracks I can join?
No fixed limit. The constraint is memory: the joined result is held decoded before it is written, so a very long combined file on a phone may run out of room. Several hours of speech is fine on a desktop.
Will there be a click between tracks?
Only if the tracks themselves end and begin at non-zero amplitude, which is a property of the source audio rather than the join. Adding a short gap avoids it entirely.
Does joining re-encode the audio?
The samples are copied as decoded, so nothing is compressed a second time. The only change is the 16-bit WAV output, which is lossless relative to what the browser handed us.