The Best Web Banner Size

If you’re a graphic designer for a brand or media buyer at an agency, knowing different web banner sizes is insanely important when it comes to display advertising.

How do you decide which web banner size you should create and buy media for?

Web Banner Size Guidelines

To advertise on Google Ads (formerly Google AdWords), it’s important to know the different banner sizes that Google supports.

Over the years, it has expanded its offerings into four types of ad sizes: Square or Rectangle, Leaderboard, Skyscraper, and Mobile. Within these are 20 types of ad sizes, the most common of which are displayed in the table below:

web banner size table

According to Google, the most successful ad sizes tend to be wider than taller.

Google says that its most effective web banner sizes are:

  • the 336 x 280 large rectangle
  • the 300 x 250 medium rectangle
  • the 728 x 90 leaderboard
  • the 300 x 600 half page

The Best Web Banner Size

To choose a winner, the most important thing to consider is how consumers are viewing your banner ad. This means taking device into consideration.

Mobile is currently king (with $76.17B in ad spending on mobile alone…), so it’s important to choose a size that is mobile-optimized.

Which means the winner is…

300 x 250 web banner size

The 300 x 250 web banner!

Google optimizes this particular size for mobile and it’s the most popular ad unit size offered across different publishers.

In OmniVirt tests of 360° ads, the 300 x 250 mobile unit consistently outperforms others, even when the same creative and size is on desktop. In fact, the mobile unit outperforms desktop at 16X the CTR. We’re releasing our 2019 Performance Report soon— subscribe to our blog to get it:

Know that you know different size options for banner ads, learn how to create them with our guide on 20+ tools and examples for banner ads.

Get inspiration from the best banner ads of 2018.