VAST File Recommendations

Using AdButler's VAST video ad format, we recommend uploading alternate file formats and resolutions to ensure maximum compatibility with common VAST-compatible video players. Including multiple file formats, resolutions and aspect ratios means the widest range of players will find a compatible file to play.

To upload additional VAST files to your ad item in Adbutler, use the button at the bottom of the ad item setup form.

Include additional files


Recommended Name Format

When naming your media creatives, before uploading to AdButler, be sure that you have chosen a compatible name format, and eliminate "&", ";" or "%" characters in your file names. We recommend that you use camel case, include the size, and seperate important info with an "_". For example: "FallFishingPromo_640x480.mp4".

Other platforms may have additional restrictions on character usage. They might restrict "&", ";", ".", "%", "+" and spaces. For maximum compatibility across all platforms, do not include these characters in your file name formats.

VAST File Format and Resolution Recommendations

Resolution and Aspect Ratios

Include enough options to allow video ads to render in any sized player. Include a range of high, medium and low quality options and cover the 3 common aspect ratios: 4:3, 16:9, and 5:2

The minimum requirement for VAST ad serving is to include one (1) mp4 file and one (1) webm file.

File types

Video: For maximum compatibility include both H.264 (MP4) and WebM formats
Audio: MP3 or AAC

File size

Maximum: 10mb
Recommended: Less than 3mb

Video Length

Maximum: 60 seconds

Frame Rate

Maximum: 30 FPS


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