Merge audio
Join several audio files into one — reorder them, set each file’s volume, normalise the result, add fade in/out and change the speed, then save as MP3 or WAV. Mixing runs entirely in your browser; nothing is uploaded.
Open Merge audio →What is the Merge audio tool?
A free, private tool that joins several audio files into a single track, entirely in your browser. Drop in MP3, WAV, OGG, M4A or FLAC files, drag them into order, and set each file's volume. Before saving you can normalise the overall loudness, add a fade in and fade out, and change the playback speed. The mix is rendered on your device with the Web Audio API and exported as MP3 or WAV — nothing is uploaded, and it works offline.
How to use Merge audio
- Add the files — Drop your audio files onto the tool or click to choose them. Each decoded file appears in the list with its duration.
- Order and balance — Use the arrows to arrange the playback order and each file's volume slider to balance levels (0–150%).
- Set the finishing touches — Optionally pick a fade in/out, a playback speed, and tick Normalise volume to bring the final mix to a consistent peak level.
- Merge and download — Choose MP3 or WAV, click Merge & save, listen to the result, and download the single combined file.
Frequently asked questions
Are the files uploaded anywhere?
No. Decoding, mixing and encoding all run inside your browser — the tool works offline.
Do the files play together or one after another?
One after another — the tool concatenates them in the listed order into one continuous track.
What does Normalise volume do?
After mixing, the whole track is scaled so its loudest peak sits just below full scale — evening out a merge of quiet and loud sources without clipping.
Does changing the speed change the pitch?
Yes — like a tape machine, 1.5× is faster and higher-pitched, 0.75× slower and lower. It's designed for speeding up spoken audio or slowing a passage down to study it.
Tips
- Balance each file with its own volume slider first, then let Normalise volume set the final level.
- A 0.5–1 s fade in and 2–4 s fade out makes joined clips sound deliberate rather than cut off.
- Trim each clip in the Audio trimmer first — merging is quicker when the pieces are already clean.