Replace Audio in Video

Pair a local video with a prepared music track or recorded voiceover and export an MP4. Use it for a complete soundtrack swap, then check the MP4’s soundtrack and ending. Free and without an account.

Choose a video and replacement audio

Select one file in each box. There are no volume, timing or mixing settings.

How to replace a video soundtrack

1

Choose your video

Select the clip in the video box and confirm its filename.

2

Choose the new audio

Select the finished track in the audio box. Prepare its start and length beforehand.

3

Run replacement

Start processing and wait for the download button. There is no input or result player on this page.

4

Download and listen

Open the MP4 elsewhere. Check the intended track, speech timing and final seconds. Changing either input requires another export.

A focused soundtrack replacement workflow

Two local source files

Select one video and one audio file from your device.

Compatible inputs

MP4, MOV or WebM video and MP3, WAV or M4A audio are useful starting points; codecs still matter.

A new MP4

Export can re-encode the picture and sound. Lossless quality and unchanged file size are not guaranteed.

Media stays local

Your files are processed locally, without uploading them to DojoClip.

Prepared audio, not a mixer

Bring the finished soundtrack. There is no original/new audio balance, fade or volume control.

Device-dependent processing

Keep the tab open. Duration, resolution, memory and browser codecs affect export time and success.

Video, audio and output formats

Both files must be readable by the processing path available in your browser. Successful output is MP4; there is no output-format selector. A supported extension alone is not enough.

Video: MP4, MOV, WebMAudio: MP3, WAV, M4AOutput: MP4

Example: replace a rough tutorial narration

For a 30-second screen recording, prepare a finished 30-second narration with pauses aligned to the demonstrations. Listen beforehand: there is no timeline to move a sentence later. After export, check the first instruction and the final action together with the new sound.

Prepare an excerpt with Audio Cutter, or get a track using the audio extractor. For a completely silent video, use Remove Audio. Browse all free tools.

Audio replacement questions

Is replacing video audio free?

Yes. No account, credits or DojoClip watermark are required. The original files remain unchanged.

Are either of my files uploaded?

No. Processing runs locally, although extra processing code may download. Save your MP4 before closing or refreshing the page.

Why can an MP4 or audio file fail?

Its codecs may be unsupported even when the extension is accepted. Try a compatible source in an up-to-date browser. There is no fixed size or duration cap, but device limits remain.

Can I mix music under speech or align a voiceover?

No. There is no mixing, delay, trimming, automatic synchronization or lip-sync control. Prepare one complete audio track before importing; the tool does not record or generate a voiceover.

What if the audio and video have different lengths?

Short audio ends before the picture, leaving a silent tail. Longer audio is cut around the video’s end. The tool does not loop, stretch or fade the replacement automatically. Match the lengths beforehand for a deliberate ending.

Does it keep any of the original soundtrack?

The replacement takes the place of the original audio, including dialogue and background sound. If you want voice and music together, prepare them in one finished audio file.

Does this clean up the original speech?

No. It uses a separate audio file; it does not remove noise, isolate voices or repair clipping in the original recording.