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

In the fast-paced world of digital marketing, first impressions are everything. Whether you are launching a high-converting Google Display campaign, designing ads for social media, or placing promotional banners on your blog, using the correct dimensions is the difference between a professional brand and a pixelated mess.

When your ad dimensions do not match platform requirements, ad networks will automatically crop, stretch, or reject your creatives. This leads to wasted ad spend and lower click-through rates (CTR).

This comprehensive guide covers the most popular, high-performing standard web banner sizes, where to use them, and best practices to make your designs pop.

1. The Top-Performing Google Display Network Sizes

Google’s Display Network reaches over 90% of internet users worldwide. To maximize your reach across millions of websites and apps, focus on the “IAB high-impact portfolio”—the sizes that generate the highest volume of impressions and conversions.

Leaderboard ($728 times 90$ px)

• Best Used For: The top of a website page (header) or directly beneath main navigation menus.
• Why it works: Because it sits “above the fold” (visible without scrolling), it commands immediate user attention.
• Tip: Keep your headline punchy and pair it with a contrasting call-to-action (CTA) button on the right side.

Medium Rectangle ($300 times 250$ px)

• Best Used For: Embedded inside article text (in-content) or within sidebar columns.
• Why it works: This is arguably the most versatile and high-converting banner size on the web. It fits seamlessly into mobile and desktop layouts alike.
• Tip: Because of its square-ish aspect ratio, it allows for creative product photography alongside brief copy.

Large Rectangle ($336 times 280$ px)

• Best Used For: High-impact text integration and sidebars.
• Why it works: Slightly larger than the Medium Rectangle, it gives designers a bit more breathing room for text and imagery, often yielding higher click-through rates.

Half Page / Large Skyscraper ($300 times 600$ px)

• Best Used For: Wide sidebar columns.
• Why it works: Also known as a “half-page ad,” this format offers massive visual real estate. It allows brands to tell a visual story, showcase multiple products, or display rich animations.

2. Mobile-Specific Banner Sizes

With mobile devices accounting for over half of all web traffic, designing for smaller screens is non-negotiable.

• Mobile Leaderboard ($320 times 50$ px): The gold standard for mobile web browsing. It typically sits at the very bottom or top of mobile screens. Keep text extremely minimal—users are scrolling fast.
• Large Mobile Banner ($320 times 100$ px): Twice the height of the standard mobile leaderboard, giving you more legibility for text and a clearer CTA button on smartphones.

3. Quick Reference: Standard Banner Dimensions

| Format Name | Dimensions (Width $times$ Height) | Primary Placement |
| :— | :— | :— |
| Leaderboard | $728 times 90$ px | Header / Top of page |
| Medium Rectangle | $300 times 250$ px | In-content / Sidebar |
| Large Rectangle | $336 times 280$ px | In-content / Sidebar |
| Half Page | $300 times 600$ px | Wide sidebar |
| Mobile Leaderboard | $320 times 50$ px | Mobile screen top/bottom |
| Large Mobile Banner | $320 times 100$ px | Mobile screen top/bottom |

4. Best Practices for Designing High-Converting Banners

Knowing the sizes is only half the battle. To turn passive browsers into buyers, follow these golden rules of banner design:

• Keep it Simple: Don’t clutter your ad. Stick to a clear hierarchy: Logo $rightarrow$ Value Proposition $rightarrow$ Call-to-Action (CTA).
• Design a Clear CTA: Use contrasting buttons like “Shop Now,” “Learn More,” or “Claim Offer.” Users should instantly know what happens when they click.
• Mind File Sizes: Heavy files slow down page load speeds, causing users to abandon the page before your ad even renders. Keep static images under 150 KB (optimized JPEGs, PNGs, or modern WebP formats).
• Respect the Rule of Contrast: Ensure your text stands out against the background. Avoid putting light text over a bright, busy photographic background without a dark overlay.

Summary

When planning your next digital marketing campaign, start by designing for the Big Four—the Medium Rectangle ($300 times 250$), Leaderboard ($728 times 90$), Half Page ($300 times 600$), and Mobile Leaderboard ($320 times 50$). Covering these core dimensions ensures your brand looks polished, professional, and ready to capture clicks across every device.