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Video Creative Guidelines

Your guide to delivering Oscar winning Video campaigns

Justin Nield avatar
Written by Justin Nield
Updated over a week ago

Last Updated: January, 2024

What are Video Ads?

Video is the “bread & butter” of advertising and comes in all shapes and sizes. These come in various sizes and duration, catering to a wide range of ad formats. Amongst these are Interstitial and Rewarded ad placements, which ensure high viewability and click-through rates (CTR), resulting in higher engagement with the advertised product.

Video creatives follow the VAST protocol, a standard defined by the IAB to ensure seamless communication between ad servers and video players when serving video ads.

Common Video Ad Placements


Interstitial ad placements are usually placed during transition points on the app lifecycle, for example, when completing a level on a gaming app or navigating to a new page on a weather app. Placing an ad on these instances makes it more likely for users to welcome and engage with the ad.


Rewarded ad placements are presented to the user at times of much need, offering the user a reward in exchange for opting in to watch a video creative. While most commonly used on gaming apps, they can also be leveraged on non-gaming apps such as dating apps.


There are plenty of non-interstitial, non-rewarded video ad placements such as in-stream video, in-feed video or in-article video.

To learn more about full-screen video creative experiences, as well as rendering differences across exchanges, make sure to check out our dedicated Creative Rendering Experiences section.

Endcards (companion ads)

Also known as companion ads, endcards are image or html creatives that are displayed either upon video completion or after skipping the video (on skippable placements).

They provide an additional instance for the user to interact with your creative and can, specially if dealing with HTML interactive endcards, can have a signficant impact on your creatives performance.

Navigating Video Supply

Video ad placements can be easily identified in Inventory Discovery under the Video Creative Type.

If you want to learn more about which Ad Exchanges support Interstitial and Rewarded Video supply, you can check the latest data on Inventory Discovery, or visit our Ad Exchange Dossier article.

Video Creative Specs

VAST (Video+ Companion)

Portrait (9:16)

Lanscape (16:9)


min: 720x1280
max: 1080x1920

min: 1280x720
max: 1920x1080

File format: .MP4, h264
Playback Speed: >24FPS

File-size: All video >10mb will be compressed as needed. We don't accept Video >150mb

Companion ads: Image assets equal to the dimensions of the assigned video.
File format: JPEG, JPG, PNG, GIF
File-size: <700kb

Best Practices for Serving Video Creatives

  • ENDCARD - Always include an endcard!

    Interstitial and Rewarded are the most common ad placements with video support, and these always support endcards. Make sure to include at least an image endcard, but we highly recommend exploring HTML endcards in order to drive higher engagement.

    Your creative will be able to serve on placements which do not support endcards as well, with only the video portion of the creative being served.

  • ORIENTATION - Portrait > Landscape

    Most mobile user use their phones in a vertical / portrait position, as such, the majority of bid requests generated correspond to portrait oriented impression opportunities.

    While it is recommended to always leverage portrait and landscape versions of your creatives in order to maximize your reach (in terms of eligible bid requests), make sure to never stick to only Landscape should you be importing these from other platforms such as Youtube or CTV.

  • SIZE - Bigger is not always better

    Video creatives are amongst the heaviest in terms of file size. Most ad exchanges only allow for video creatives up to 10MB to ensure a smooth, consistent creative experience. Some of them even suggest less than 5MB.

    Our recommendation is to always try and keep your video size under 5MB, or at least 10MB.

    If your video creative size exceeds 10MB, do not worry, Kayzen's got you covered. As long as your video creative is under 150MB, Kayzen will automatically compress your video creative to a size below 10MB.

  • RESOLUTION - It's a mobile phone, not an IMAX screen :)

    Kayzen matches video creatives to eligible bid requests by looking at the orientation, regardless of the video resolution.

    This means that:

    • Portrait creatives will be eligible for ALL portrait oriented bid requests.

    • Landscape creatives will be eligible for ALL landscape oriented bid requests.

    • Squared creatives will be eligible for ALL portrait and landscape oriented bid requests, though resulting in poorer experience due to the introduction of black borders.

    Thus, having several creatives with the same orientation but different resolution will not result in incremental impression reach.

    Taking this and the size aspect above in mind, we recommend building your creatives with a single resolution befitting a mobile phone screen.

  • DURATION - Consider the exchanges minimum and maximum video durations.

    The allowed minimum and maximum duration vary depending on the Ad Exchange and placement within the publisher's app. You can learn more about these nuances on our Full-Screen Creative Experiences by Exchange article, but here is a short summary:

    • Avoid videos shorter than 5s, as this is usually the minimum duration for many ad exchanges. Doing so will guarantee maximum reach for your creative.

    • 5s videos have the same reach as 6s, 7s or 8s videos. Make sure to focus on creatives that perform and remove those with low performance that do not grant incremental reach.

    • Videos below 30s have the highest potential reach amongst all ad exchanges, so this should be your bread and butter for your video campaign strategy.

    • Certain ad exchanges allow for videos up to 60s, 90s or 120s, so don't be shy to try long-form videos as well.DURATION - On Video creative duration

  • AD FORMAT - Know your placement!

    Always keep in mind the creative experience differences between Interstitials and Rewarded, as well as the nuances that each ad exchange's rendering provide. For example:

    • AppLovin's Interstitials have a skip button delay of 8 seconds. That means that during these first 8 seconds your creatives are not skippable. Make sure to get your message through and focus your short-form videos here as they will be practically non-skippable from beginning to end.

    • Rewarded placements are non-skippable during the first 30 seconds. Make the most of this time and the user's willingness to view the creative (remember they opted in!) to leverage your longer videos here (+20s). Do not waste the opportunity with 5s videos when they user is willing to spend 30s with your creative!

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