Overlay Audio
âšī¸ How it works:
- Select two or more audio files
- Tracks are layered to play at the same time
- Download one mixed MP3 instantly
Overlay and Mix Audio Tracks Online for Free
Layer two or more audio tracks on top of each other so they play at the same time. Unlike joining (which puts files one after another), overlaying stacks them — perfect for adding background music behind narration, layering sound effects, or blending several sources into one mix. Every track starts together, and the result downloads as a single MP3. No sign-up and no watermarks.
How to Overlay Audio
- Select two or more audio files above (up to 10 MB each).
- On the next screen, set each track's volume with its slider — for example, turn the music down so a voiceover sits on top.
- Optionally tick "Normalize final mix", then mix and download your layered MP3.
Features
- Simultaneous mixing – all tracks play together, starting from the same point
- Per-track volume – a gain slider for each file, so you can duck the music under speech
- Normalize option – even out the overall loudness of the final mix
- Mixed formats welcome – combine MP3, WAV, OGG, FLAC, AAC, M4A and WMA
- Single MP3 output – one mixed file, ready to download
Overlay vs Join: What's the Difference?
Overlay plays tracks simultaneously (track A and track B at the same time). Join plays them one after another (track A, then track B). Use overlay when sounds should be heard together; use Join Audio when you want them in sequence.
Common Use Cases
- Background music – add music behind a voice recording or narration
- Sound effects – layer effects over an existing track
- Podcast production – blend intro music with a voiceover
- Music layering – combine separate instrument or vocal takes into one mix
Frequently Asked Questions
The mix lasts as long as the longest track. Shorter tracks simply stop when they end while the longer one keeps playing.
Yes. Each file gets its own volume slider on the mixing screen, so you can turn one track down (for example, music sitting under a voiceover) before mixing. For bigger changes you can also pre-level a file with our Adjust Volume tool.
Overlay layers tracks so they play together at the same time. Join Audio places tracks back to back so they play one after the other.
Stacking loud tracks adds their levels together, which can occasionally cause clipping. If that happens, pull one or more track sliders down before mixing, or tick "Normalize final mix" to even out the overall level.
Related Audio Tools
- Join Audio – play tracks one after another instead
- Adjust Volume – level a track before mixing
- Trim Audio – cut a clip to length first
- Fade Audio – add fade-in and fade-out
- Convert Audio – change the mixed file's format