3 Best Free Ways to Add Audio to MP4 – Desktop and Online

Video is a typical mixture of media files that contains video clips, still images, soundtracks, and subtitles. And one of the best tricks to enrich your video content is to add audio to MP4 or replace the original audio track with external MP3 audio files. Namely, you can make stunning vlogs with stylish background music, add your own voiceover, fix footage with poor audio recordings, and beyond.

Today, we are going to introduce the top 3 free methods to add MP3 or audio in other formats to MP4 on Windows, Mac, and Online. Let’s find the best free video editor and spice up your videos now.

Method 1. Add Audio to MP4 in VideoProc Vlogger

VideoProc Vlogger is a capable yet east-to-learn video editing program for Windows and Mac. It’s completely free and aims at helping people enjoy video editing without worrying about skills or tech knowledge.

No matter what you want, adding music to videos, replacing audio in the source video, or recording a voiceover for your footage, VideoProc Vlogger enables you to achieve the best results with the least effort.

What’s more, VideoProc Vlogger is packed with a series of handy features to bring your video to the next level, to name a few, EQ presets, A/V sync, voice changer, aesthetic transitions, color grading, speed ramping, and so on.

VideoProc Vlogger – A Full Set of Features to Add Audio to MP4

• Combine FLAC, M4A, AAC, or MP3 and videos without losing quality.
• Total control over audio volume, speed, pitch, sample rate, etc.
• Best solutions to enhance sound quality and create AFX like a pro.
• Unique audio analyzer to detect music beats and audio silences.
• Record voiceover, sync video and audio, change voice/pitch, etc.

Download and Install VideoProc Vlogger to Add Audio to MP4 for Free!

Step 1. Create a new project and import media files to VideoProc Vlogger.

Launch VideoProc Vlogger on Windows or Mac. Complete basic settings to start a new editing project. Drag and drop the audio file in MP3 or other formats and the MP4 video to its “Media Library”.

Step 2. Add audio track to MP4 video.

Drag the MP4 file to the video track and audio to the audio track. You can drag the audio clip to make it align with the MP4. If you are replacing the original audio track with this audio file, mute the MP4 by clicking the volume icon on the video track.

Step 3. Adjust the audio and edit the MP4.

Click to select the audio in the timeline, and you can split, cut, speed up, or slow down the audio with features in the toolbar. Also, you can apply advanced edits to it in “Audio Editor”.

Step 4. Export the video from VideoProc Vlogger.

Preview the entire video. If you are satisfied with the result, hit “Export” above the timeline. Finally, VideoProc Vlogger starts to add MP3 to MP4 and saves the final video on your computer.

Pro Tips

How do I add a picture and convert MP3 to MP4?

If you want to convert MP3 to MP4 with images, just import files of images, MP3, and MP4 into VideoProc Vlogger, drag them to the timeline, then choose MP4 format in the export settings.

Can I enhance the audio file that I will add to my video?

Yes. VideoProc Vlogger offers multiple solutions to enhance your audio in its audio editor, for example, removing background noise, increasing the volume, applying audio filters, and more.

Method 2. Add Audio to MP4 in VLC

As the most known media player in the world, VLC features many options to fine-tune video and audio playback, for example, playing extra audio files and videos synchronously. I guess that’s not what you want. But don’t worry about it as there’s a workaround in VLC to add an external MP3 track to MP4 and save it as a new file.

Note: Strictly speaking, this is about replacing instead of adding MP3 audio to MP4, because VLC will remove the original soundtrack. This method is not recommended if you want to add background music while keeping the original sound in the video.

Step 1. Open VLC. Click “Media” > “Convert/Save” > “+Add” to import an MP4 video to it. Hit the “Convert/Save” button at the bottom to proceed.

Step 2. Click the wrench icon in the “Profile” option. Choose “Audio codec”, unselect “Audio” to disable its soundtrack, and save the changes.

Step 3. Export the video to your computer and load the MP4 video without audio track to VLC.

Step 4. Check options of “Show more options” > “Play another media synchronously” to add your audio file.

Step 5. Switch the option of “Play” to “Convert/Save” at the bottom.

Step 6. Hit the wrench icon and select “Keep original audio track” in “Audio codec”. Save the changes.

Step 7. Choose an output folder and name the file with the .mp4 extension. Hit “Start” to ask VLC to add the audio file to your MP4.

Method 3. Add Audio to MP4 Online

Obviously, it’s a Rube Goldberg process to add MP3 audio to MP4 using VLC media player. For anyone who just needs a simple combination of MP3 and MP4, the Add Audio to Video utility in Online Converter comes to cost you the least time and effort.

Note: You are not allowed to add audio to video exceeding 200MB in Online Converter. Besides, you cannot check the result until saving it in your computer.

Step 1. Go to the official website of the online tool: onlineconverter.com.

Step 2. Choose “Video Converter” and select “Add Audio to Video”.

Step 3. Choose and upload the MP4 file and the audio file from Windows or Mac.

Step 4. Select “Keep Audio in Video”. Next, adjust the volume and position if needed.

Step 5. Hit the “Add” button. When online converter completes processing, download the new MP4 video to your computer.

FAQs about Adding Audio to MP4

How to add mp3 audio to mp4 video in iMovie?

Create a project and add the .mp3 and .mp4 files to the timeline of iMovie. Then you can drag the clips to audio and video tracks to adjust their positions. Lastly, export them as a whole to your Mac in MP4 or MOV format.

Can I add an audio track to MP4 in HandBrake?

No, HandBrake has no feature for adding audio files to MP4 videos because it’s a professional video transcoder without versatile editing options.

How to add audio to mp4 video on YouTube?

After uploading an MP4 to YouTube, navigate to “Channel content” > “Editor” on YouTube Studio. Then you can add free music to your video as well as adjust the mix level of the audio and video. But what you can edit on YouTube is very limited. So it’s better to edit the audio and video offline using VideoProc Vlogger and upload it to YouTube.