The Ultimate Guide to Standard Web Banner Sizes (2026 Edition)

Whether you are launching a high-converting Google Display campaign, designing native ads for social media, or planning a website redesign, getting your dimensions right is the first step to digital success.

In the world of display advertising, a few pixels can mean the difference between a high click-through rate (CTR) and an ad that gets completely ignored. This comprehensive guide covers the most popular, high-performing standard web banner sizes and best practices to maximize your creative impact.

Why Standard Banner Sizes Matter

Ad networks like the Google Display Network (GDN) process billions of impressions daily. Adopting standard sizes ensures that:

• Your ads fit seamlessly into publisher inventory across millions of websites.
• Your creative assets scale correctly without unwanted cropping or distortion.
• Your campaigns load quickly and comply with modern file-size and format guidelines.

Top-Performing Standard Web Banner Sizes

Below are the most widely used and effective web banner formats categorized by their layout and placement.

1. The Leaderboard (728 × 90 px)

• Best Placement: Typically found at the very top of a website header or embedded within high-traffic content.
• Why It Works: It is one of the classic display formats. Because it appears “above the fold” immediately when a page loads, it commands high visibility and consistent engagement.

2. The Medium Rectangle (300 × 250 px)

• Best Placement: Embedded within text articles, sidebars, or at the end of blog posts.
• Why It Works: Often called the “workhorse” of digital advertising, the medium rectangle generates the highest volume of impressions and clicks across the web. It blends naturally with surrounding content and performs exceptionally well on both desktop and mobile web viewports.

3. The Large Rectangle (336 × 280 px)

• Best Placement: In-line with article text or sidebars.
• Why It Works: Slightly larger than its 300×250 counterpart, it provides extra breathing room for compelling visuals and clear calls-to-action (CTAs).

4. The Half Page / Skyscraper (300 × 600 px)

• Best Placement: Sidebars and sticky page margins.
• Why It Works: Also known as a “half-page” ad, this high-impact format offers double the vertical space of a standard rectangle. It allows brands to tell a richer visual story and yields higher engagement rates due to its sheer size.

5. Mobile Leaderboard (320 × 50 px & 320 × 100 px)

• Best Placement: Fixed at the bottom or top of mobile device screens.
• Why It Works: With mobile traffic dominating global internet usage, these formats are essential for reaching smartphone users without disrupting their browsing experience. The 320×100 variant (large mobile banner) provides double the height for clearer typography and buttons.

Quick Reference: Standard Banner Dimensions

| Ad Format Name | Dimensions (Width × Height) | Ideal Device / Placement |
| :— | :— | :— |
| Medium Rectangle | 300 × 250 px | Desktop & Mobile / In-content |
| Leaderboard | 728 × 90 px | Desktop / Top of page header |
| Half Page | 300 × 600 px | Desktop / Sidebars |
| Large Rectangle | 336 × 280 px | Desktop & Mobile / In-content |
| Mobile Leaderboard | 320 × 50 px | Mobile / Sticky bottom/top |
| Large Mobile Banner| 320 × 100 px | Mobile / High-impact mobile view |

Best Practices for High-Converting Web Banners

Knowing the dimensions is only half the battle. To turn passive viewers into active customers, keep these golden rules in mind:

Pro Tip: Keep your design uncluttered. The most successful banners feature a clear value proposition, a high-contrast background, and a prominent call-to-action (CTA) button like “Shop Now” or “Learn More”.

• Prioritize Readability: Stick to clean, bold fonts. Avoid intricate script typefaces that become illegible at smaller scales (especially on mobile).
• Optimize File Sizes: Heavy files cause slow page loads, leading ad networks to reject your creative. Keep static images under 150 KB and use modern compression where possible.
• Design for Animation (Wisely): If you use HTML5 or animated GIFs, keep animations subtle (under 15–30 seconds) so they do not distract users from the publisher’s core content.
• Test Multiple Sizes: Always run responsive display campaigns or test a mix of sizes (