Today we are uncovering the most effective mobile ad sizes and formats for boosting inventory monetization. Mobile in-app advertising formats for mobile in-app monetization have seized the digital advertising market in a landslide.

In 2021, the overall mobile ad expenditure grew to a stunning $288 billion, and that’s much more than was forecasted by Juniper research and industry experts a few years ago.

Meanwhile, after taking a little peek into the future and doing a little math, we'll see that mobile web (mobile websites) formats are not only destined to stay on the edge of glory but also surpass the boldest growth expectations.

According to recent data by Statista research (Jan 13, 2022), mobile ad expenditures recorded a growth of 26.6 percent between 2020 and 2021. This figure is expected to reach a high of $413 billion by 2024. It's time to find out how to boost your monetization with mobile campaigns: what to choose a leaderboard ad, full screen, autoplay video ads, entire screen interstitial, or maybe custom banner sizes?

Best mobile advertising formats: Who’s been playing good?

Two types of common mobile ad formats displayed impeccable monetization performance; in-app ads and mobile ads.

With over 90% of Facebook’s ad profits coming from mobile platforms, it’s hard to understate the importance of a correctly tuned and robust strategy for mobile ads.

Naturally, every developer and publisher wants to know the best mobile ad sizes that surpass all others in generating revenues. Advertisers strive for better brand awareness, click-rates, and CTRs.

The reality is trickier; there’s no universal or standard size of mobile ad or magic mobile advertising format that works equally perfect on all types of platforms or devices. In fact, different sources may suggest various mobile ad specs and placement.

For instance, while some experts advise that the best mobile banner ads should be 300*250, the IAB suggests 300*50 and 320*50 (also known as the mobile leaderboard for fixed-size mobile banner ads). Nothing will give a better impression on ad unit performance than particular in-app ad type testing, but we can give it a good starting point with this.

Also, it might be interesting for you to read our article about "The future of mobile ads."

The first mobile in-app advertising ad unit was delivered in 2009. In a few years, it superseded the other known ad formats and snatched over income on the mobile market. As time passed, mobiles became customary for users, and mobile advertising faced massive changes because users’ behavior changed drastically.

Instead of installing new applications and Internet surfing, user attention now focused on fewer apps that had all necessary functions inbuilt. Understanding that developers moved to in-app ad surroundings that suggested using such attractive mobile advertising formats as social, display advertising, and other ads.

When we talk about standard IAB mobile ad sizes, there’s no need to dig deep into analytics to notice that larger mobile banner sizes became prevalent within the past few years.

The data delivered by various ad tech platforms demonstrates that their average click per mille growth during the last couple of years reached a 152% record with the following 57% average CTR enhancement.

Most sought after mobile display ad sizes

Our study of 1.5 billion mobile ad impressions delivered interesting results - it was observed that the mobile leaderboard ad size (320*50) is the most popular, accounting for more than half of all mobile display campaign demand. The medium rectangle (300*250) followed quickly behind.

It is not surprising to note that the mobile leaderboard ad display size provides the most revenue for publishers, generating 48.64% of total revenue in this ad size category. While the medium rectangle generates 41% of total ad revenue. This makes the medium rectangle the second best while the mobile leaderboard has perched in the first row. 

Best mobile ad formats: which ones should I go for?

Regarding certain mobile ad unit size does not come down to following the latest trends or reviewing only ad types that generate exceptionally good revenues to other mobile app developers or publishers. It is not about only choosing the best mobile ad sizes.

It’s also about selecting a good quality ad network. Worth mentioning that certain ad networks specialize in best mobile ad types while others can focus on desktop.

Additional questions to ask yourself for determining the best mobile ad size:

  • What mobile ad formats does your network or ad exchange support?
  • What advertising contents does your network or ad exchange offer? Are they related to your niche? What mobile ad size best fits your ad network’s typical ad inventory?
  • What mobile specific technology do you need to integrate?
  • Who is the target audience of the advertiser? Will the mobile campaign appeal to your audience? 
  • What mobile ad types appeal to your audience the most?
  • What mobile ad sizes and standard ad formats does your website or app support?
  • What ad compensation methods does your ad network offer? (CPC, CPM, CPV, CPA). Are the compensation methods based on the ad form and ad size? 
  • Is your website or app optimized for various mobile device types and sizes? (phone, tablet, small screen, and large screen)
  • How do you plan to define the metrics for ad performance?
  • How exactly will you test mobile ad unit sizes?
  • Which mobile web ad formats and sizes specifics can complement your app, improve its effectiveness?

Mobile Video Ads:


According to HubSpot, video content is currently the most preferred media ad strategy among advertisers. In another research, 92 percent of marketers consider video an important aspect of their marketing strategy because it enhances conversion and brand awareness.

For publishers, optimizing for mobile video content should be a major part of ad offering plans in 2022. It is increasingly becoming in-demand for advertisers, and it also appeals to your audience. 

According to recent data, 54% of people want to watch more video marketing content. Also, 83.3% of internet users in the US viewed video content during the last couple of years. In other words, a typical video unit would be appreciated by more than half of your audience. This implies that your app or website will generate more views, and the ad network will compensate you more.

Common mobile display ad sizes featured on the picture above generate better engagement and enhance average eCPM if the video duration is between 15 to 30 seconds - sufficient time for memorizing the ad without causing user irritation.

A popular form of video marketing is the rewarded video unit. Rewarded video ads incentivize users for watching full-screen videos. They are commonly found in mobile games.

According to our experience, the mobile video play rates for applications are better (14.0%) than the mobile video ad performance on the web (8.3%) that, however, doesn’t impact the completion rate dramatically that stays equal for both variants.

Publishers must, however, use mobile ads cautiously. Users will become irritated and exit the app if an ad is annoying or not properly positioned. 

The pros and cons of video ads for publishers:

Users enjoy typical video ad contents, and video ad formats offer one of the highest eCPMs in the mobile ad category. With the average eCPM for IOS devices at $7.34, and $6.3 for Android devices, publishers can expect increased ad revenue. However, publishers must evaluate their website and avoid too many placements so that user experience would not be compromised.

Mobile Banner Ads


Mobile banner is an increasingly popular advertising format, the shape of which can be ranged from animated to static images popping up at the user’s screen while they use an app or a mobile site.

The banner can appear from various corners of the mobile devices screens, and such a mobile ad unit is traditionally the simplest one in terms of implementation. Most companies and advertisers use mobile banner ads because they are relatively cheap and represent a very effective way of increasing brand awareness. Hence, publishers would have access to large demand with the banner ad.

Although mobile banner advertisements have one of the lowest average CPMs according to our data (between $0.50 and $1.20), they can still be profitable due to their decent viewability rate. The best mobile banner ad sizes are 350*50 and 300*50 for mobile devices.

Regarding the standard banner ads and sizes on mobile devices, the publisher should ensure that the banners are properly placed. Also it’s important to choose proper sizes to avoid the so-called banner blindness effect caused by the massive popularity of banner ads.

The pros and cons of banner ads for publishers:

A banner ad is popular and lightweight; such ads will not slow down your website speed or cause lags. At the same time, they’re quickly falling off the radar as many companies now can afford more eye-catching, sophisticated types of mobile ads.

Mobile Interstitial Ads


Interstitial ads are widely used types of digital advertising, preferred by both advertisers and publishers. They can be found springing up on web pages, but they are most common in apps and gaming worlds.

Because of its high impression rate, an interstitial ad is a very popular ad format that leads to lots of downloads (which means more earnings for publishers).

Interstitial ads offer different dimensions that build an immersive user experience thanks to the new mobile display ad sizes stretching on the whole user screen. User’s behavior triggers these mobile ads; these ads pop up the moment the person opens the app, navigates it, or simply switches among the pages or modes.

Text, graphics, and rich media ads are all examples of interstitial unit. An interstitial unit can come in the form of text, graphics, video, rich media, or playable ads. And they are often resistant to ad blockers making them more productive in generating ad revenue.

Because interstitial mobile units have the propensity to compromise user experience, they should be carefully built into the app to prevent hampering user flow. According to Google, they should be "displayed at natural moments in an app's flow, such as when switching between tasks or between stages in a mobile game."

Mobile interstitial ad sizes are usually 320*480 or 1024*768 pixels. With this, interstitial ads cover the user's full screen, catching attention at best. They can, however, result in a non intrusive advertising strategy if executed clumsily. Ensure that the ad placement and timing do not obstruct user flow.

The pros and cons of interstitial ads for publishers:

A standard interstitial ad can deliver an immersive ad to the end-user; both publishers and developers of the app can stay confident - their ad will be seen. At the same time, such an ad can cause more irritation among users.

Native Ads


Native ads are easily integrated display advertising ad units; This mobile ad type belongs to the list of popular mobile advertising formats that don’t heavily affect the user’s comfort because they come up harmonized with the rest of the textual or video content.

Mobile native advertising is becoming increasingly popular among major publishers due to its efficiency in generating revenue. Furthermore, this form of advertisement is highly relative to the content on a website, blog, or app. As a result, your viewers will be more comfortable viewing published ads because it is something they are interested in. According to our data, users are 25% more inclined to engage with native marketing content than a banner ad.

This ad format is often called the best mobile ad format due to its proven efficiency to generate 53% more views than a banner ad. In fact, many users (32%) report being ready to share the native marketing content with friends or relatives because those mobile advertising formats are known to be often confused with the actual website content. Thus, it makes native a very popular mobile ad format.

A study observed that native marketing content has more click-through rate than a traditional ad, which means that publishers will gain more revenues in case their network functions according to cost per click model.

The pros and cons of native ads for publishers:

Mobile native advertising formats put full control over the creatives and ad campaign timing in the developers’ hands. The users also see such mobile ad units as a normal part of the content. However, because the advertising content is often mimicking the design of the app or website, this ad style might be misleading for potential customers (if not tagged properly). This can be a turn-off for people, leading to low traffic.

Unlike many other simple formats, mobile ad formats like these require outstanding design to blend with the surrounding content. 

Rich Media Ads


You're displaying ads as a publisher to increase CPMs and definitely revenue. While your site's users are likely becoming irritated by the excessive number of advertisements interrupting their journey through your site, you would wish for a different experience. You would want your users to engage with the ads you publish. This is why ad tech companies are continually working to develop new ad formats like rich media as a part of display advertising campaigns.

A rich media ad is a combination of several interactive elements designed to make an ad responsive. Rich media incorporates a variety of beautiful and engaging content types, such as images, videos, graphics, animations, etc. They're made to stimulate user action.

Unlike the typical banner ad, rich media contents are not static ads and can adapt to different mobile screen sizes. You may also move them across a webpage or expand, minimize, and resize them.

Rich media advertising formats can exist within the app ecosystem and on website versions adapted for mobiles. 
These ads have a fluid design that adapts to the user's screen and mobile device motions. The goal is to improve user experience by displaying interactive ads.

Standard and drop-down rich media mobile ad units are considered the most popular among advertisers. However, different formats of rich media ads are designed to achieve different purposes. According to an AB study, rich media advertising increases user interaction, improves brand recall, and enhances message recall. This can elicit more impressions and increased ad revenue from your display advertising campaigns.

The pros and cons of rich media ads for publishers:

With the help of expandable ads, and because they are not static banners, it is easy to overcome banner blindness syndrome. Still, it is also important to avoid user frustration while using expandable rich media ads. Expandable ad unit can be heavy in size, which can cause latencies and poor page load times that affect user experience (in case of unit weight is not optimized or you have problems with an ad server).

While there are no specific standard mobile sizes, there are however popular sizes that are recommended. The popularity of ad sizes can change with time and is often influenced by user preference and popular screen sizes at a particular time. 

Notwithstanding, the popular mobile ad sizes in 2021 are still relevant in 2022. Here are the five best mobile ad sizes to consider.

300*250 pixels

Also called the medium rectangle, many advertisers create their ads with this size in mind. Medium rectangle is frequently referred to as the most popular mobile ad size. The medium rectangle (300*250) pixel size also made up popular mobile ad sizes 2020. You may be guaranteed to reach a lot of advertisers if you have ad slots of this size on your site.


This size is similar to the 300*250 rectangle size with little difference. The similarities between both mobile ad sizes make them popular. Although Interactive Advertising Bureau didn’t list this ad size as the most popular, it is still frequently used by major SSPs.


The 320*100 size is recognized by Google as one of the most popular banner size. It is tailored to suit the dimensions of most devices. It is often referred to as a large mobile banner. While the large mobile banner is efficient, it is not recommended to have multiple placements of this size because it could frustrate users. This banner size is currently served by Google display network.

320*50 (mobile leaderboard)

The 320*50 also known as the mobile leaderboard is one of the best ad sizes for years. Like the 320*100, mobile leaderboard is also designed to suit the screen size of most mobile devices. This ad size also helps to reduce the possibility of intrusive advertising.


Expandable ads are becoming more popular in recent times; they are usually more user-friendly and less intrusive. The 320*480 supports expandable ads perfectly and suits most devices. They also enhance rich media ads result.

Optimization recommendations for publishers

Trying to make money with your inventory can be a tricky endeavor. If you're not careful, you'll end up sacrificing user experience for ad placement, bombarding your users with too many intrusive advertisements. On the other hand, you might unknowingly adopt a less engaging ad format or ad content because you want to enhance the user experience. 

Finding the proper balance is the key.
Admittedly, the most effective ads are frequently the most obtrusive, negatively impacting the users app journey. 

This is why choosing a competent adtech company is so important. If an advertisement appeals to a user, it is less likely to be considered intrusive. Relevant ads have to be responsibly placed and with good graphics. Here are some recommendations that will guide you.

Adopt data analysis

Do not place ads randomly. To find out where your ad placements perform best, you should conduct research and rely on credible data. There are available tools and solutions that give you this analytics.

Optimize for a variety of ad sizes and types

If your inventory supports different ad types and mobile ad sizes, naturally, you boost monetization opportunities with those various types of ads. This would put you at the top of the ad publishing chain. 

You know there is a competition with many publishers jostling for good payment per impression. Offering flexibility automatically gives you good leverage. You will be able to choose the best advertisers.

It is important to note that there are no standard mobile ad sizes. Optimizing for multiple sizes would help minimize the possibility of empty ad spaces. You will have more advertisers interested in bidding on your ad spaces.

Embrace A/B testing

A/B testing is a method of comparing two options to find out which works better. It would be best to compare various ad placements and formats and how your users react to them. This way, you will know which ad types have the most positive ad impressions on your website.

Display ads reasonably

Make sure you don't bombard your users with too many intrusive ads in a single session. It will likely disenchant them, leading to less traffic in the future. If you choose to display expandable ads or other intrusive ads, ensure that you follow professional guidelines.

Quality of ad creative

Be concerned about the quality of ad creatives on your website. Users are more likely to engage with high-quality ad media. Accept ad servers that provide high-resolution media. 

Colors that are excessively intense, too much writing, or visuals that are of low quality should be avoided. Advertisers should only highlight key features or products. Ad media that isn't up to this have a significant negative impact on the user experience.

Mobile ad units vs. app types 

Industry experts claim in-app, and mobile advertising represent a proven way to make free apps profitable; only 10% of users are inclined to commit in-app purchases, so the remaining 90% are normally monetized with video, banners, and other ads.

In-app ads help diversify the risks: even if your application loses its former position in the store or no longer attracts new users, you will still earn from monetizing on existing ones.

Mobile advertising will be equally effective for the apps brimming with users with impressive daily session duration and the ones that are only used occasionally (most important thing - mobile ad unit size and placement should be chosen wisely),
Learn more about new opportunities with SmartyAds mobile ad formats.

To sum up

A few years back, mobile advertising was only displayed through the banner format, today there are multiple display formats. In the future, mobile advertising will only become more creative and innovative. As the industry advances, more formats will emerge. As a publisher, you should be able to spot new display trends and be willing to adapt them to enhance revenue generation. While doing this, it is crucial to consider what works best for your users so that you don’t scare them away with too many intrusive ads. You still need their impressions to earn from ad display.

Studying your audience's behavioral patterns and preferences while they are on your website or application would suggest you the right choice of ad display formats.

However, deciding on the best mobile ads format and size may be difficult. The truth is, there is no specific best, rather a range of best mobile ad sizes. You should optimize for versatility. Several ad networks, ad exchanges, brand advertisers, and even Google Adsense would prefer to engage inventories that offer great adaptability. 

Video ads, banner ads, interstitials, rich media, and mobile native ad formats are in high in-demand so it’s time to benefit from them.

Register at SmartyAds SSP and connect your app to endless monetization opportunities.

Written by
Irina Kovalenko, CMO of SmartyAds
June 2018