Good Advertising: Ad Format Recommendations

Read Time: 7 minutes

One of the freedoms that come with the modern advertising is the ability to forget about limits. With fast connections, hi-res displays, and fancy cameras, old limits on ad formats can seem quaint. Sure, your VAST ad can be 4k. Or your banner can use that really nice photo you took with your 26-megapixel camera. But it doesn’t need to.

Keeping your ads within certain limits will make them more effective. They’ll load faster, users will react better to them, and advertising partners will have an easier time integrating them. AdButler gets asked all the time about file recommendations, so we figured it was high time we put them out in an easy to read form.

The below four tables outline our recommendations for the most common ad formats. They are for the most part based on the IAB’s recommendations, which you can find here. Our recommendations are definitely a bit more general, but I like to think they’re more realistic.

How to read our recommendations

The below tables all follow a similar structure, and most of the tips can be applied to the other ad formats. For instance, try and keep your ad file size as small as possible by staying below the recommended. And, if you’re going above the max, you should be absolutely certain you need that space.

Especially if you’re working with mobile. Mobile can be extremely sensitive to advertising, and the capabilities of people’s phones can vastly differ depending on demographics.

The only other recommendation I can offer is to work within the formats. If you want something animated, use an HTML5 banner. Animated gifs work, but they’re huge and cumbersome. CSS animations, like the kind that banner creators use, or video is almost always a better avenue. Know what you’re trying to do and use the right tools.

Display Banners
File SizeMax 300 KB – Recommended under 100 KB
DestinationTry to avoid redirects and URL shorteners
File Type.jpeg, .png, static gif
  • You have a lot of freedom here, but also the ability to make ads really fast. There’s no such thing as too fast of an ad.
  • If you’re using your own CDN, make sure it employs compressions that are compatible with all browsers. Or, better yet, compress the ad on your own!
  • Try to avoid using animated gifs. If you want to have an animated ad, we recommend using the HTML5 rich media format.


HTML5 Display Banners
File SizeMax 1 MB – Recommend under 300 KB
DestinationTry to use AdButler’s destination macros as opposed to hard coding a destination + macro integration. It gives you more access to our macros and enhances the user’s experience.
  • HTML5 ads are really unique and, depending on what you’re doing, you have to keep in mind lots of different limitations. One common hiccup is tracking scripts. Some programs or designers can include scripts for tracking purposes that can really slow down your banner. Know what’s in your banner.
  • As with display, make sure all your images are compressed, and if you’re using externally hosted resources, to employ a good CDN.


File SizeMax 10 MB – Recommend 2 MB per minute
DestinationTry to avoid redirects and URL shorteners
File Type.mp4, .webm, .mpeg, .mov, .wmv
  • VAST allows you to add multiple versions of the same file. When the tag is loaded, the video player then picks whichever creative best fits the device. We recommend adding as many different variations across resolution and file type that you can to take advantage of this flexibility. As a minimum, try to have two different file types with two different resolutions for a combined four files.
  • Try and pick realistic resolutions for the ad. Not everything needs to be 1080.


HTML5 In-banner video
File SizeMax 10 MB – Recommend 2 MB per minute
DestinationTry to avoid redirects and URL shorteners
  • In-banner video is an HTML5 rich media banner that’s wrapped around a video play, either playing a static ad or calling a VAST tag. Most of the same considerations for VAST are true for in-banner video.
  • One thing to keep in mind too is that in-banner video is usually very small, so you can usually go for a smaller resolution than standard VAST.


Liam Workman

Liam is an account manager and blog king at SparkLit, the SaaS company behind AdButler and FourEyes. He loves rock climbing, hiking, coding, and being your friend.