About the Audio Overlay
Audio Overlay on Video drops background music, narration, sound effects — anything audible — on top of a video and lets you line it up to the frame using a shared timeline. Both tracks stay in view at the same time, so you can see exactly where the audio meets the picture before you commit to a render.
Everything happens inside your browser. Your video and audio are never uploaded, never queued on a server, and never logged. Close the tab and they're gone — safe for client cuts, unreleased music, voiceovers, podcast clips, or any sensitive footage you'd rather not hand to a third party.
What you can control
- Two-track timeline: The video strip and the audio clip render side-by-side with a shared ruler. Drag the audio left or right to align it to specific moments in the video.
- Waveform on the audio clip: See peaks and silences inside the audio block so you can drop hits, beats, or stings exactly on the right frame.
- Start time: Set when the overlay audio kicks in (drag the clip on the timeline or type a precise value in seconds).
- Audio skip: Trim the leading portion of the overlay audio — useful for skipping intros or silence before the part you actually want.
- Original video audio volume: 0–150% slider for the video's own audio (keep it under the music, boost it past 100%, or kill it entirely).
- Overlay audio volume: 0–150% slider for the added audio. Default 80% so the new track doesn't overpower the original.
- Mute original video audio: One checkbox to silence the source completely — replaces video audio rather than mixing.
- Loop overlay to end of video: If the audio clip is shorter than the video, loop it until the video ends.
- In-browser render: The final video downloads as a standard MP4 with the mixed audio baked in — seekable in any player, ready for any platform.
Common uses
- Adding background music to vlogs, social clips, or product videos.
- Layering narration or voiceover on top of a silent screen recording or B-roll.
- Dropping sound effects (whooshes, stings, transitions) onto specific frames.
- Replacing the original audio of a noisy recording with a clean studio take.
- Adding music beds to interview footage or tutorials.
- Creating reels and shorts where the audio drives the cut.
Tips for the best results
- Drop both files first — the timeline only renders once it has a video and an audio source loaded.
- Drag the audio clip past the left edge of the timeline to trim its start. This is the same as setting Audio skip, just visual.
- Keep overlay volume around 60–80% when the original video already has speech — anything higher tends to drown out dialog.
- Tick "Mute original video audio" if you're fully replacing it with narration. Mixing leftover background noise into a clean voiceover usually sounds worse than a complete swap.
- Turn on "Loop overlay" if you're adding ambient music to a longer video and only have a short loop clip.
- Preview before rendering. The playback uses real-time mixing, so what you hear is exactly what gets baked into the final file.
- If your audio clip starts with silence, use Audio Slicer first to trim it cleanly — then your start times will line up perfectly.
No accounts, no upload queue, no length limits — drop a video, drop an audio file, drag to align, render. The output is yours to share, post, or edit further.
Common questions
How do I add music to a video for free?
Load the video, load the audio track, and drag the clip along a shared timeline until it starts exactly where you want. Export the combined video. No watermark, no trial, no video editor to learn.
Can I add a voiceover to a screen recording?
Yes. Record or generate your narration, overlay it on the video, and use the waveform view to line your words up with what is happening on screen. Paired with our text-to-speech tool, you can narrate a video without ever recording your own voice.
How do I sync the audio to the right moment?
The timeline shows the video as thumbnails and the audio as a waveform, so you can see the beat and the scene change and align them precisely instead of guessing.
Does my video get uploaded while adding audio?
No. Everything is processed in your browser, so the family video or work demo never touches a server, and big files start processing instantly instead of uploading for an hour.
Will there be a watermark on the exported video?
No watermark, ever. The export is your video with your audio and nothing else added.
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