Introduction

Mobile ads are now the primary driver of digital ad revenue, and every year their dominance continues to expand. As more and more users move their browsing, shopping, and content consumption to using a smartphone, publishers are seeing a considerable increase in traffic coming from mobile devices. This transition is causing advertisers to allocate a larger portion of their budgets to in-app ads, mobile web inventory, and ad creative that is tailored for small-screen displays. Therefore, publishers who focus on optimizing their mobile ad sizes will find themselves in the best position to take advantage of these increasing revenue opportunities.

Whether you operate a content-heavy blog, an entertainment site, or a niche information site, selecting the best mobile ad sizes and formats has a strong impact on your own success. Having the correct sizing improves viewability, increases click-through rates (CTR), and allows advertisers to bid more aggressively on your inventory. On the other hand, poor sizing can result in wasted ad space, lower engagement, and lower earnings. This is the advantage of working with a professional ad management platform, same some as Newor Media, as they provide a performance advantage for publishers through advanced optimizations, ad layout testing, and dynamic ad placements.

In this guide, we’ll analyze the highest-performing mobile ad sizes, look at new mobile ad formats, and discuss which ad placements publishers should focus on in 2025. We’ll tell you about each size’s performance, its position on your site that performs best, and ad formats you can consider that fit in with user behavior to garner greater overall revenue. You will leave the guide knowing what steps to take to create a mobile ad layout that accommodates a profitable layout that also provides a good experience for users.

Why Mobile Ad Sizes Matter

When it comes to mobile advertising, finding the appropriate ad size is not just a design choice; it is also a monetization choice. The size and format of mobile ads impact user experience, click-through rates (CTR), and has an overall effect on fill rate. Smaller or improperly sized ads can fade into the rest of the content causing engagement to suffer. In addition, overly large placements can disrupt the reading experience, creating accidental clicks that can annoy a user and negatively impact long-term traffic. Striking a balance is key for long-term monetization.

Mobile screens can differ significantly from one device to another, and responsive design has become a baseline expectation. Features for mobile devices vary and are approached differently between smartphones, phablets with larger screens, and tablets. That is why choosing the right mobile banner ad sizes will help ensure that the ads load properly, fit well on the screen, and are viewable without interrupting the content flow. Ads that are responsive hold their shape and definition, and that gives advertisers the confidence to bid higher for your inventory.

It is also important to consider industry standards. The IAB (Interactive Advertising Bureau) established sizes that have proven to perform well, while Google includes viewability metrics, mainly for mobile web and in-app placements. High viewability translates to stronger advertiser interest and higher CPMs. By aligning your ad strategy with these best practices, you ensure that every placement works efficiently, supports a positive user experience, and maximizes your earning potential.

 

Common Mobile Ad Formats Explained

Understanding the different mobile ad formats is essential for building a balanced and profitable monetization strategy. Each format serves a unique purpose, offers different levels of engagement, and caters to varied advertiser goals. As mobile traffic grows, publishers are also seeing an evolution in new mobile ad formats designed to improve interaction and deliver a more immersive experience.

Banner Ads represent the most utilized format. It can be displayed in a static format, or in a responsive format, and be located at the top or the bottom of the screen. The simplicity of Banner Ads creates a format that is both lightweight and effective for generating impressions at scale. Responsive banners respond to the device’s screen size, but still remain clear and readable for the user, regardless of the device.

Interstitial Ads are placements that take over the entire screen between content pages, or a natural transition in the app. This type of ad placement is designed to capture the user’s attention, making it more valuable for the advertiser. However, it is necessary that the user is only interrupted, or engaged, if the user knows why they are being interrupted.

Native Ads are exactly what they imply- the ad is as native to the site and app, displaying content that matches the native tone, style, and layout of the app or website. The highest degrees of engagement are linked to this type of advertising since the experience feels more natural and less intrusive in the user’s browsing context.

Video Ads can take on many different forms such as in-stream ads (ads played in the video), out-stream ads (ads that appear somewhere within the content of the article), and rewarded video ads (that require an action from the user in exchange for incentive- a very popular ad form in gaming and app’s). Video ads typically present with the strongest CTR and completion rates.

Rich Media Ads consist of interactive advertising elements including animation, expandable panels, and swipe formats. As one of the fastest growing new media ad types for mobile, rich media also engages the reader at a deeper level for the sake of storytelling, and generally has a higher yield in revenue potential for the publisher.

Top 10 Mobile Ad Sizes for Publishers (Ranked)

Choosing the right mobile banner ad sizes is essential for maximizing viewability, revenue, and user experience. Below is a ranked breakdown of the best mobile ad sizes for 2025, along with ideal placements, performance insights, and recommendations aligned with Google AdSense and IAB-approved standards.

 

1. 320×50 (Mobile Leaderboard)

Ideal Placement: Top or bottom of pages
Why It Works:
This is one of the most universal mobile ad sizes, supported across nearly every device and ad network. Its slim profile makes it unobtrusive while still delivering consistent impressions and a strong fill rate.
Performance Tip: Use at the top of your page for higher visibility. Keep the bottom unit as a secondary revenue booster.

2. 300×250 (Medium Rectangle)

Ideal Placement: In-content or at the end of content
Why It Works:
The 300×250 is one of the most profitable ad units on both desktop and mobile. It offers excellent visibility and delivers strong CTR because it’s placed within or near the content flow.
Performance Tip: A/B test placing this unit mid-article vs. post-body to determine where your audience engages most.

3. 320×100 (Large Mobile Banner)

Ideal Placement: Top or bottom of pages
Why It Works:
This size takes up more vertical space than the 320×50, making it easier for users to notice—and increasing CTR. It’s also recommended by Google AdSense for improved viewability.
Performance Tip: Use sparingly to avoid overwhelming users; prioritize above-the-fold placements.

4. 250×250 (Square)

Ideal Placement: Sidebars on mobile web or lightweight interstitial use
Why It Works:
While not as common as other formats, this size works well in responsive layouts where screen dimensions vary. It’s useful in apps or smaller content areas.
Performance Tip: Combine this size with adaptive design to prevent distorted rendering.

5. 300×600 (Half Page Ad)

Ideal Placement: Mid-content or long-form content pages
Why It Works:
This tall, visually prominent format is considered premium inventory by advertisers. It captures attention and drives strong engagement when used strategically.
Performance Tip: Avoid placing it above the fold; keep it mid-scroll to reduce disruption.

6. 336×280 (Large Rectangle)

Ideal Placement: Below articles or mid-scroll
Why It Works:
Similar to the 300×250 but larger, this size offers exceptional performance in long-form content where users naturally pause.
Performance Tip: Ideal for mobile web; ensure enough padding around it to maintain readability.

7. Interstitial Ads (Full-Screen)

Ideal Placement: Between page transitions
Why It Works:
Full-screen formats demand user attention, leading to high CPM and excellent advertiser demand. However, moderation is key to avoid harming user experience.
Performance Tip: Follow Google’s guidelines: show interstitials only during natural breaks—never on first click or during critical navigation.

8. Native Ad Units

Ideal Placement: Embedded within feed or inline content
Why It Works:
Native ads blend seamlessly with content, making them non-intrusive and highly engaging. They often outperform standard banners in CTR and time spent.
Performance Tip: Keep the style consistent with your site’s colors and typography for maximum authenticity.

9. Rewarded Video (In-App)

Ideal Placement: Gaming apps or utility apps with clear user actions
Why It Works:
Rewarded video delivers exchange-based value: users willingly watch ads to unlock rewards, premium features, or content. This produces high completion rates and strong monetization.
Performance Tip: Limit frequency to maintain reward value; allow users control over when they watch.

10. In-Feed Video Ads

Ideal Placement: Social-style feeds, news feeds, or content scrolling areas
Why It Works:
These are incredibly effective due to passive engagement—users encounter the ad while scrolling. They offer high viewability and brand-safe exposure.
Performance Tip: Ensure autoplay is muted by default for compliance and better user experience.

Additional Notes for Publishers

Both Google AdSense and the IAB recommend mobile-friendly, high-viewability ad formats with clear spacing and proper padding. They specifically highlight 300×250, 320×50, and 320×100 as performance-driven sizes for mobile web. For publishers, combining responsive units with these proven formats ensures stronger performance across different devices and screen orientations.
By prioritizing these best mobile ad sizes, you can build a balanced strategy that improves revenue while maintaining a smooth user experience.

Mobile Video Ad Formats: The New Revenue Driver

As mobile viewership increases, video is, the best monetization option for publishers, even greater than standard display units. In every aspect, mobile video ad formats greatly outperform traditional, as it applies to engagement, viewability, and revenue. People are spending more time viewing short-form videos as they scroll through social platforms, news feeds, and in-app content, creating an ideal environment for effective video ads. The ad demand increases because real-time media buys are allowing for increased CPMs for the video impressions.

In-stream video ads are among the best performing ad formats. Placement of the ads is “in-stream” meaning they’re played in the video content before, during, or after the video plays; and both viewability and completion rates are some of the highest performing metrics for video ads. Where applicable for a publisher with video content or the ability to embed a video player, in-stream video ads are a great way to monetize and increase revenue.

By contrast, out-stream video ads do not require a video player and can run in the content areas of the article, social feed, etc., between paragraphs as someone scrolls a page. Out-stream video ads automatically play once they appear on the screen and stop playing once the ad is no longer viewable on screen. Out-stream ad units have high viewability and higher Click-through rates than analogous content for the reason that they appear naturally in an experience.

The fastest-growing format among new mobile ad formats is rewarded video, primarily used in apps and gaming environments. Users actively choose to watch a short video in exchange for in-app rewards, premium content, or bonuses. This opt-in nature results in industry-leading completion rates—often above 80–90%—and highly engaged audiences.

Overall, mobile video formats deliver higher CTR, stronger viewability (often 70–90%), and superior ad recall. For publishers looking to diversify revenue and tap into premium advertiser demand, video ads have become an essential part of the monetization strategy.

Choosing the Best Mobile Ad Sizes for Your Website

Choosing the right mobile ad sizes for your site is more than following best-practice guidance. Each site has different user experiences, site layout limitations, and traffic behavior. First, get to know your audience—geography matters, and so does the devices they prefer to use. In areas where the mobile use is much heavier than desktops, or where there is more competitively priced advertising, larger mobile ads can first begin, while the opposite could be true for areas which are smaller. And the type of user matters as well; news users might experience your mobile ads differently than users who are interested in entertainment and games.

A responsive site matters as well for ad inventory. Responsive sites can accommodate more types of ad sizes, so the ad units flow better across the devices being used. If the site is built using a fixed layout this could limit options to place ads… meaning that perhaps a 320×50 or a 300×250 could work best. Be sure to look at your traffic—as a general rule of thumb, if more than 60-70% of your visits come from mobile devices, justifying and investing in mobile-first optimized ad layouts and even bigger mobile ad banners will drive better performance.

Make sure to control the density of your ads to not adversely affect Core Web Vitals. Too many ad units can increase page latency, reduce page speed, and reduce the user experience. Google penalizes intrusive or slow ads. It is expected for the advertiser, revenue goals should be balanced with performance and best practices guidelines.

Finally, A/B testing is essential for refining your strategy. Test different placements and sizes simultaneously, track CTR, viewability, and RPM, then select the combination that delivers the strongest returns. Continuous optimization ensures your monetization strategy remains aligned with user behavior and shifting advertiser demand.

Real-World Examples

To understand the real impact of choosing the right mobile ad formats and sizes, it helps to look at how different publishers have improved performance through strategic adjustments.

Example 1: News publisher improves CTR with 320×100 banners

A mid-sized news publisher faced declining engagement with standard 320×50 mobile banners. After testing several options, they switched to 320×100 large mobile banners, which offered greater visibility without being intrusive. The result was a 25% increase in CTR and a noticeable improvement in viewability, leading to higher CPM bids from advertisers. This demonstrates how even a slight change in ad size can significantly influence performance on mobile-heavy sites.

Example 2: App developer boosts retention using rewarded videos

A utility app developer integrated rewarded video ads into their onboarding and daily reward system. By offering users optional incentives—such as unlocking features or gaining extra credits—the app maintained a positive experience while increasing monetization. Completion rates exceeded 85%, and user retention improved by 18% over three months. This highlights how rewarded video formats can support both engagement and revenue without disrupting usability.

Example 3: Lifestyle bloggers benefit from native and in-feed ads

Several lifestyle blogs saw stronger monetization after integrating native and in-feed video ads within their content feeds. These formats blend with the storytelling style of lifestyle content and feel more organic to the user. CTR rose by 30%, and average viewability surpassed 80%. The seamless integration improved user experience while enabling higher-quality advertiser demand.

These examples reinforce that choosing the right formats drives engagement, enhances monetization, and supports long-term revenue growth.

Tools & Platforms for Mobile Ad Optimisation

To maximize revenue from mobile traffic, publishers need more than just the right ad sizes—they need the right technology stack to manage, optimize, and test their placements. Several platforms offer reliable solutions for refining your mobile ad strategy and boosting performance.

Google Ad Manager remains the industry standard for serving and managing responsive display ads. Its dynamic allocation, ad unit control, and sophisticated targeting options make it ideal for publishers looking to fine-tune their mobile inventory. GAM also supports adaptive and responsive units that automatically adjust to device dimensions.

AdPushup is widely used for layout optimization and ad performance testing. With advanced A/B testing capabilities, multivariate experiments, and widget-level controls, publishers can test multiple layouts and mobile ad sizes to see which combinations deliver higher CTR, RPM, and viewability.

For publishers focused on header bidding and yield optimization, Setupad provides an effective solution. It specializes in mobile-first monetization with lightweight scripts, prebid integration, and advanced reporting. This helps maximize competition for impressions and boost mobile ad revenue.
In the in-app ecosystem, MoPub (now consolidated under AppLovin) continues to be a go-to platform for app monetization. It supports a wide range of formats—including interstitials, native, and rewarded videos—and offers strong demand from premium advertisers.
Choosing the right mix of ad sizes and formats can drastically improve your mobile ad revenue.

Challenges in Mobile Ad Monetisation

Even with the tremendous growth of mobile advertising, publishers still face several obstacles that may hinder their revenue. The first is a phenomenon known as banner blindness. This is when users unconsciously overlook ads that are repeated or impractical in terms of placement. Likewise, ad fatigue can decline performance levels if the publisher uses similar formats or creatives too often.

In addition to banner blindness, another hurdle is site performance. For example, heavy ads, auto-play videos, or even sub-optimal layouts can cause pages on the mobile website to load slowly or have layout shifts, both of which result in a poor user experience, and a sorry Core Web Vitals score. In turn, those factors directly related to speed will increase the site’s bounce rate. More bounce rate not only compromises impressions but also puts revenue at risk.

Finally, publishers must adhere to strict privacy regulations such as GDPR in Europe and Apple’s App Tracking Transparency (ATT) framework which limits tracking users, thereby limiting audience targeting precision. As a result, both advertising demand and CPMs can be negatively affected. In addition to regulation, ad blocking and ongoing cookie deprecation weakens ad visibility and attribution as well.

Fortunately, there are solutions. Techniques like lazy loading ensure ads only load when they are close to entering the viewport, reducing page weight and improving speed. AI-driven placement optimization tools can analyze user behavior and automatically select optimal ad locations and formats. By adopting smarter layouts, optimizing load times, and using AI-powered tools, publishers can overcome these challenges and maintain strong mobile ad monetization results.

Future Trends in Mobile Ad Formats

As technology continues to advance, publishers anticipate significant shifts in the manner in which mobile advertising is presented and experienced. One of the fastest growing trends in mobile advertising is the rise of interactive and shoppable ad formats that enable engagement with a product without leaving the page. Augmented reality (AR) experiences are also growing in popularity, providing engaging, immersive experiences that showcase or replicate products or environments – ultimately fostering a stronger human connection between users and brands. These developments will continue to establish the bar for new mobile ad formats that encourage user interaction versus passive viewing.

 

At the same time, mobile video ad formats, specifically in-stream, out-stream and rewarded video ads continue to account for the largest share of ad spend. As users are spending more time on video-first platforms, and short-form content is becoming an easier option to consume, we see advertisers shifting more budget towards video placements that maximize engagement, viewability and conversion. Publishers who are strategically positioned with video content or scrollable formats, will benefit the most.

 

The user experience and sustainability are also becoming larger themes associated with mobile advertising. The combination of lighter-weight creatives, reduced obtrusive formats, and greener models of ad delivery help conserve page speed and data consumption, while privacy-oriented advertising targeting solutions deliverthe same level of compliance without sacrificing performance.

Publishers who adopt these emerging formats early will maintain a competitive edge. By experimenting with innovative placements, leveraging advanced video solutions, and keeping user experience at the forefront, publishers can stay ahead in an increasingly dynamic mobile advertising landscape.

Final Thoughts

Selecting the appropriate mobile ad sizes is one of the most effective methods for improving viewability, engagement, and revenue potential. As mobile continues to dominate the digital ecosystem, it is vital for publishers to recommend ad formats that perform well, as well as fit naturally with the overall user experience with mobile content.

It is extremely important to find the correct balance between monetization and user experience. Overcrowding pages with disruptive ad placements can hurt performance and deter potential visitors. Thoughtfully selected mobile ad formats enhance a user’s engagement with their content and provide a higher CPM. By considering the user’s potential behavior relating to the layout, the responsive design, and recovery from errors, a publisher’s overall monetization strategy will feel more natural and more effective.

Continuous testing is essential. Experiment with different ad placements and ad sizes, and modify in real- time according to Ad Manager performance. It is important to keep plugged into the latest trends, and enlist the help of a professional ad management platform to ensure you are using the latest optimization tools, and kept informed of current trends. Keeping flexible and aware will give you an advantage in mobile monetization.

Optional FAQ

Q1: What is the most common mobile ad size?

The 320×50 mobile leaderboard remains the most widely used mobile ad size. Its universal compatibility across smartphones, lightweight load time, and strong fill rates make it a reliable choice for publishers looking to maximize impressions without disrupting user experience.

Q2: Which mobile ad format has the best engagement?

Among all mobile ad formats, video and native ads typically deliver the highest engagement. Video ads attract attention through motion and storytelling, while native ads blend seamlessly into the content, leading to higher CTR and improved interaction rates.

Q3: Are interstitial ads effective?

Yes, interstitial ads can be highly effective due to their full-screen visibility and strong advertiser demand. However, they must be used strategically and sparingly. Overuse can frustrate users, increase bounce rates, and negatively affect overall site performance.

Q4: How do I test different mobile ad sizes?

A/B testing is the best approach. Tools like Google Ad Manager, AdPushup, and Setupad allow publishers to experiment with various layouts, placements, and sizes. Track metrics such as CTR, viewability, and RPM to determine which configurations perform best.

Q5: What’s the trend for 2025?

The major trend for 2025 is the rapid growth of interactive and video-first ad formats. Publishers are adopting mobile video units, shoppable ads, and immersive formats to improve monetization, maintain user engagement, and stay aligned with evolving advertiser demand.