Instagram allows only certain types of videos. The following are the requirements to upload a video

Size: maximum width 1080 pixels (any height)
Frame Rate: 29.96 frames per second
Codec: H.264 codec / MP4
Bit rate: 3,500 kbps video bitrate
Audio: AAC audio codec at 44.1 kHz mono
Length: 60 seconds
Filesize: 15MB

Generally Video Codec or Audio Codec is the problem.

To upload video to Instagram from PC/Mac or iPhone/Android without losing quality, you are required to make sure that the output video files are in the limits above. However, some users are bothered by the large size of videos recorded with HD cameras or incompatible video formats. In those cases, you're suggested to convert/compress the Instagram upload videos first. Here we use the Instagram video uploader 

MacX Video Converter Pro.

  • Convert HD/SD videos in WMV, MOV, MKV, MTS etc to Instagram supported formats MP4 with world's fastest speed.
  • Compress 4K/HD videos with large file size that are shot with hd cameras to smaller video size without losing quality for smooth uploading to Instagram.
  • Download videos from 300+ sites like Facebook, YouTube etc for Instagram video upload from web links
  • Advanced editing features to edit Instagram video¬†like trimming, subtitle adding, effects adding, multiple parts merging into one clip etc
  • Download Instagram video for offline playback on iPhone SE/6S, iPad Air 2, Samsung Galaxy S7 edge+ and more.

Secure Download

Secure Download