Sometimes you want to merge an audio track to the source video to overlap the audio of a video file with some other audio. Then Wondershare Filmora might come in handy. This video editing application supports various video formats like MP4, FLV, AVI and MKV and has an ability to add/replace the audio in video file without requiring any extra codec. You can even record your own voiceover and add it to the original video. The article introduces how to merge video and audio with this powerful tool.
To begin with, get a free trial copy of Wondershare Filmora.

1. Import the video and audio files

Wondershare Filmora has a simplistic and intuitive interface. You can either drag and drop files to the item tray or click “Import” button to load as many audio or video files as you need. This video editing tool supports a vast range of formats, so you won't confront any loading problem.

2. Merge Video and Audio

After importing your videos to the program, drag the video and audio files to the Video and Audio Timeline respectively. After that, rearrange the order and even preview them, just in case you want to make sure you got the right files. If the audio file needs editing, double click the file to pop up the audio editing panel. Here, you can speed up/slow down speed, adjust volume, set fade in/fade out, tune the pitch of the audio as you like.

Tip: If you want to replace the original audio track of the video file, right click it and choose “Audio Detach”. The audio track will appear in the Audio Timeline. Hit “Delete” in your keyboard to remove it and then add your own audio file to the corresponding position. You can also click “Record” (it’s on the toolbar above Timeline) to bring up the Record Audio dialog and record your own voice.

3. Export the file

After merging the video and audio files, hit “Create” to export your video. Then choose to save as any file format you like. Besides that, you can also save and play the videos on different devices like the iPhone, iPad, Zune, directly upload video to YouTube, or burn to DVD.

So if you need an audio or video merger for your media files, give Wondershare Filmora a try and see what it does for you.