attach .wav file to .mp4 file

If you want to play a video (.mp4) with your audio (.wav) you can simple start playing both at the same time.

You may try iDealshare VideoGo which can helps to add audio track to video like add WAV to MP4 or add background music to video even without recode video files.

You may prefer to this guide named How to add audio to video? It can help you archive the following goals:

 1. Support adding one audio track to video MP4, MKV, AVI, MOV, FLV, WMV, MXF, WebM, ASF, DV, MPG, RM, AVCHD, SWF, MOD, MTS, OGV, 3GP, etc;
 2. The added audio track can be in the following formats: MP3, WAV, AAC, M4A, WMA, AC3, MP2, AIFF, CAF, QCP, APE, FLAC, DTS, RA, OPUS and more;
 3. Support adding background music with or without re-encoding the source file;
 4. Support deleting the added audio tracks or background music once you don't need them;
 5. Edit video in many aspects: trim, crop, merge, split, rotate, add watermark/effect/subtitles, change audio channel, adjust audio volume and more;
 6. Convert various kinds of video and audio files like MP4, MOV, AVI, WMV, MKV, FLV, MP3, WAV, AAC, M4A, etc;
 7. Works on both Mac and Windows.