The 320×100 Large Mobile Banner: Why Bigger is Often Better

In the fast-paced world of mobile advertising, grabbing attention is a game of pixels. While the standard [320×50 mobile leaderboard] is the most common ad size, it often suffers from “banner blindness”—users have trained themselves to ignore that thin strip at the bottom of their screens.

Enter the 320×100 Large Mobile Banner.

By doubling the height of the standard leaderboard, the 320×100 format offers advertisers a significant advantage: 100% more canvas space to tell their story, showcase their product, and drive clicks.

Let’s explore why the 320×100 is quickly becoming the preferred choice for performance marketers and how you can use it to increase your mobile revenue.

What is the 320×100 Ad Size?

The 320×100 Large Mobile Banner is a smartphone-specific ad unit measuring 320 pixels wide by 100 pixels tall.

• Width: 320px (Fits perfectly on almost all smartphone screens)

• Height: 100px (Tall enough to display a clear image and text)

• Ratio: 3.2:1

It serves as a “middle ground” between the smaller 320×50 leaderboard and the much larger 300×250 medium rectangle (which disrupts content). The 320×100 is small enough to sit at the top or bottom of a page, but large enough to command attention.

320×50 vs. 320×100: Which Should You Choose?

If you are torn between the standard leaderboard and the large banner, consider the following comparison:

Feature	320×50 (Standard)	320×100 (Large Banner)
Screen Space	Minimal (Unobtrusive)	Moderate (Noticeable)
User Experience	Excellent (Easy to ignore)	Good (Visible but not blocking)
CTR Potential	Lower	Higher (More visibility)
Creative Freedom	Text only (mostly)	Text + Clear Images
Inventory	Extremely High	High

The Verdict: If you just want cheap impressions, use 320×50. But if you want clicks and conversions, the 320×100 is statistically proven to perform better because it allows for richer graphics and clearer Call-to-Actions (CTAs).

Why the 320×100 is High-Performing

1. It Combats “Fat Finger” Syndrome

One of the biggest issues with the smaller 320×50 ads is accidental clicks. Users trying to scroll often accidentally tap the thin banner. While this increases click numbers, it ruins conversion rates (and annoys users). The 320×100 is tall enough that clicks are usually intentional.

2. Better Visuals

With 100 pixels of height, you can actually include a product shot, a face, or a logo that is legible. You aren’t forced to squeeze your message into a tiny sliver of space.

3. Google AdSense Optimized

Google AdSense and other major ad networks highly recommend this size as a high-performing mobile unit. It fits neatly into the “flow” of content (like between paragraphs) without looking like spam.

Design Tips for a Killer 320×100 Ad

Since you have double the height, use it wisely. Do not just make your text bigger—add value.

• The “Two-Column” Layout: Use the left half for your product image and the right half for your headline and button. This layout works perfectly in the 3:1 aspect ratio.

• Contrasting Button: Ensure your “Sign Up” or “Shop Now” button is a different color than the background.

• Legible Fonts: You can get away with slightly larger font sizes here. Ensure your main value proposition is readable at a glance.

320×100 Validator Tool

Building ads for mobile requires precision. If your file is even one pixel off (e.g., 321×100), ad networks like Google Ads may reject it.

Use the free tool above to check if your image is the exact 320×100 size before you upload it to your campaign.