Banner ad
Also called web banner, banner advertising
What is a banner ad?
A banner ad is a rectangular advertisement, usually an image or short animation, placed on websites and in apps. Clicking it takes the viewer to the advertiser's site. Banner ads are the oldest form of display advertising and come in standard sizes, so one design can run across thousands of sites through ad networks.
The common sizes come from the IAB (Interactive Advertising Bureau): 300×250 (medium rectangle), 728×90 (leaderboard), 160×600 (wide skyscraper), 300×600 (half page), 320×50 (mobile leaderboard) and 970×250 (billboard). Google Display Network and other networks also accept responsive ads that adapt to the space.
In social media, "banner" often means something else: a wide image such as a LinkedIn banner, an X header or a 1.91:1 link ad.
Why a banner ad matters
Banner ads are cheap per impression and reach people across the web, which makes them useful for retargeting and for awareness. Click-through rates are low, so they work best with a clear offer and a recognizable brand.
Because space is tiny, banners force clarity: one message, one image, one action. That discipline helps all your ad creative.
How to design a banner ad
- Make the main sizes first: 300×250, 728×90 and 320×50 cover a large share of inventory.
- Put the logo, one short headline and a button-style call to action in every size.
- Use high contrast and large text so it reads at small sizes.
- Keep files small (networks set limits, often around 150 KB for static banners).
- Make the landing page match the banner's message and offer.
Banner ad FAQ
What is the most common banner ad size?
The 300×250 medium rectangle is the most widely used, followed by the 728×90 leaderboard on desktop and the 320×50 mobile leaderboard.
Do banner ads still work?
They work for cheap reach and retargeting, but click-through rates are low. Judge them on conversions and cost per result, not clicks alone.
Related terms
A display ad is a visual ad (image, animation or video) shown on websites, apps and video platforms, as opposed to text ads in search results.
Social media image sizes are the pixel dimensions and aspect ratios each platform recommends for posts, stories, ads, profile banners and link previews.
Ad creative is the visible part of an ad: the image, video, headline and text people actually see, as opposed to targeting and budget.
Click-through rate (CTR) is the percentage of people who click a link, ad or button after seeing it: clicks divided by impressions.
Retargeting shows ads to people who already interacted with your business, such as site visitors or video viewers, to bring them back to buy.