At Juillet Marketing, we know that every pixel counts to catch your customers' attention. In this article, we present the must-know banner sizes for your 2025 display campaigns - along with clear, practical tips to maximize your results.

Why are banner sizes important?‍

A properly sized banner ensures:

  • Optimal reach across ad networks: Standard formats like the Leaderboard (728x90 px) and Medium Rectangle (300x250 px) are widely supported across most ad platforms, guaranteeing maximum visibility for your ads.
  • A better user experience: Banners adapted to different devices improve user interaction with your content. For example, responsive banners automatically adjust to screen size, offering a smooth experience across mobile and desktop.
  • A better advertising ROI: Studies show that appropriately sized banners can increase click-through rates (CTR). On average, the CTR for display ads is 0.46%.

Bottom line: choosing the right size is non-negotiable for your campaign effectiveness.

The must-know banner sizes

Here are the standard formats recommended by the IAB (Interactive Advertising Bureau):

  • Billboard (970 x 250 px): Large and highly visible at the top of the page, perfect for big launches.
  • Leaderboard (728 x 90 px): Great for page headers, ideal to quickly grab attention.
  • Mobile Leaderboard (320 x 50 px): Designed for small screens. Great for being visible without being intrusive.
  • Large Rectangle (336 x 280 px): Ideal for strong visual impact within editorial content.
  • Medium Rectangle (300 x 250 px): Super versatile, performs well on desktop and mobile. Excellent in articles and contextual placements.
  • Half Page (300 x 600 px): Really grabs attention due to its size. Great for branding campaigns.
  • Skyscraper (120 x 600 px): Perfect for side columns, accompanying content reading.

The Billboard

The Billboard (970 x 250 px) is one of the most powerful display ad formats, thanks to its width and its strategic placement at the top of web pages. Its size offers a large canvas to create striking visuals, fully visible upon page load, greatly increasing the chances of capturing attention.

Advantages: Billboards are ideal for brand awareness, branding, and product launches. Their size lets you tell a strong visual story with immediate impact. According to Google studies, wide formats like this generate about 20% higher brand recall than standard formats.

Where it appears: Usually reserved for "premium" spots on media websites, news portals, or high-traffic platforms. It’s placed directly above the main content for maximum exposure.

How to use it: Design-wise, make the most of the space. Favor a clean background, a strong central graphic (product, mascot, or logo), and short text. A clear call-to-action with strong contrast is essential. Fonts should be large and instantly readable. Keep "safe zones" to avoid key elements getting cut off on certain platforms.

Mistakes to avoid: Cramming too much information. Skip long text and complex visuals that dilute the core message. A Billboard should be readable in under 2 seconds. Also, keep file size light (<150kb) to avoid slow page loading.

The Leaderboard

The Leaderboard is one of the most classic web ad formats, widely used for its balance between visibility and seamless integration.

Advantages: The Leaderboard has an excellent impression rate across most display networks. A Wordstream study shows that the 728x90 px format ranks among the top 3 best-performing formats for CTR, contributing to around 25% of global display impressions.

Where it appears: Typically at the top of pages, above main content, or at the footer - it naturally captures attention without disrupting the experience.

How to use it: Use a short, impactful message centered in the visual. Opt for large fonts and strong contrasts. Adding a clear, visible button ("Learn More", "Get Started") improves efficiency. Keep the background simple to highlight the CTA.

Mistakes to avoid: Overloading the small space with too much information. Also, not adapting it for mobile is a common mistake. Poor mobile adaption makes the ad look bad on smaller screens, reducing its impact.

The Mobile Leaderboard

The Mobile Leaderboard was built to maximize visibility on small screens. With over 60% of internet traffic now from mobile (Statista, 2024), mobile optimization is essential. Its 320x50 px size prioritizes compactness and fast readability.

Advantages: Perfectly adapted to modern mobile screens. Well-positioned at the top or bottom, it enables quick user contact without being too intrusive. Smart Insights reports that banners placed at the top of mobile screens have a 35% higher visibility rate compared to in-content formats.

Where it appears: Mostly on mobile apps, mobile websites, social platforms, and entertainment sites. Typically appears at page load or during natural browsing.

How to use it: With the limited size, the design must be ultra-clean. Use a strong image or high-contrast background to grab attention. Keep text minimal (a few words), in large, readable fonts. A call-to-action button is almost mandatory, ideally on the right. Icons can replace words to keep it clear. Also, optimize file size for fast loading.

Mistakes to avoid: Simply shrinking a desktop banner into this format is a common mistake. This format needs a design made for mobile: avoid tiny details, long texts, and cluttered elements that make touch interaction harder. Also, respect Google and Apple ad guidelines to avoid ad rejection or poor delivery.

The Large Rectangle

The Large Rectangle (336x280 px) is an expanded version of the popular Medium Rectangle (300x250 px). Its slightly bigger size lets you display elements more comfortably without overwhelming the user.

Advantages: Large Rectangles maximize visual impact while fitting seamlessly into content pages. Google AdSense says that rectangle formats like 336x280 have about 15% higher CTRs compared to more elongated formats.

Where it appears: Often inserted within content (editorial or commercial), between paragraphs or side panels. Its contextual placement boosts chances of grabbing attention naturally.

How to use it: Use the extra space smartly: strong visual hierarchy, attractive image, catchy headline, and a clear CTA. Images that blend well with the host site’s style improve relevance. A "native-like" strategy works very well for this format.

Mistakes to avoid: Trying to cram too many elements in. Avoid busy backgrounds that hurt quick readability. Also, not optimizing for retina displays can leave your ad looking blurry or amateurish.

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The Medium Rectangle

The Medium Rectangle (300x250 px) is one of the most used formats on Google's Display Network, for good reason: it balances flexibility, visibility, and performance.

Advantages: Super versatile. Google studies say the 300x250 accounts for about 40% of global display impressions, making it the king of Display formats. It adapts perfectly across sidebars, article middles, and even mobile interstitials.

Where it appears: Almost everywhere: sidebars, within editorial content, increasingly in mobile "in-feed" formats. It's a top choice for cross-platform campaigns.

How to use it: The trick is to center the design around a strong visual. Space limitations mean you must be direct: a striking image, a clear selling point, and a visible CTA. Use a "Z pattern" to guide the eye naturally. Colors should be contrasting but pleasant.

Mistakes to avoid: Shrinking down a bigger creative without rethinking the layout. Result: unreadable text, cluttered visuals, lost CTAs. Each Medium Rectangle needs to be treated as its own standalone message. Mobile optimization is also critical: it still needs to be readable and clickable even on small screens.

The Half Page

The Half Page (300x600 px) is a true vertical ad panel. It blends the reach of classic display formats with the feel of an immersive experience.

Advantages: According to Google Ad Manager, Half Pages generate 28% higher engagement rates than traditional banners. Its height lets you capture prolonged attention as users scroll.

Where it appears: Mainly in sidebars of high-traffic websites, often locked in a fixed position for max exposure. Common on news, editorial, and professional blog sites.

How to use it: Use vertical storytelling. Stack visuals logically: striking visual at the top, key argument in the middle, CTA at the bottom. Keep a clear visual hierarchy with plenty of white space for breathing room.

Mistakes to avoid: Don’t pile up too many messages. Users should understand the main point at a glance. Also, avoid low-contrast backgrounds that make text hard to read, especially on mobile.

The Skyscraper

The Skyscraper (120x600 px) is a vertical display classic. Its slim shape keeps it visible longer during page scrolling.

Advantages: Its height offers longer visibility compared to horizontal formats. Integral Ad Science reports vertical formats like Skyscrapers enjoy a 21% higher visibility rate than horizontal banners.

Where it appears: Mostly used in website side columns, particularly on desktops. Often placed in sticky zones to stay in view during content reading.

How to use it: Design vertically: start with an impactful visual or logo at the top, key message in the middle, clear CTA at the bottom. Use directional cues like arrows to guide the user’s eye downward.

Mistakes to avoid: Overcrowding the space. Avoid tiny fonts and placing key elements only at the bottom, as not all users will scroll fully. Also, keep file weight optimized to avoid slow loading.‍

Best practices for your display creatives:

  • Keep files light: recommended weight < 150kb.
  • Use .JPG, .PNG, or .GIF formats depending on needs.
  • Always add a clear CTA: "Discover", "Try Now", "Get Started".
  • Keep design simple and readable, especially for mobile.
  • Respect your brand identity: colors, fonts, tone.
  • Create a clear element hierarchy: logo, main message, CTA.

In Conclusion

Using the right banner sizes is a simple but powerful foundation for your campaigns' performance.
Always consider your goal, the device, and the user experience. Then, test and adjust.