Every standard HTML5 banner ad size you need - from leaderboards to rectangles - with specs, best practices, and tips for building banners that perform.
Using the wrong banner size means your ad won't serve, won't render correctly, or won't be eligible for the highest-traffic placements. Ad networks have strict size requirements, and getting them right from the start saves hours of rework.
HTML5 banners are now the standard across display advertising. Flash is gone, and static images are increasingly replaced by lightweight animated HTML5 units that perform better and respect user experience.
One of the most common display placements. Sits at the top of the page above the fold. High visibility, moderate click-through rates. Works best with a clear headline and one CTA.
The most widely available and purchased display ad size globally. Works in sidebars, within content, and at the bottom of articles. If you only build one size, build this one.
Similar to the medium rectangle but slightly larger. Often outperforms the 300x250 in terms of CTR due to increased visibility.
A premium placement with strong engagement. Dominates the sidebar and gives you much more creative space. Works well for brand awareness campaigns.
A high-impact format used for above-the-fold placements on desktop. Excellent for brand campaigns with strong visuals.
The standard mobile banner. Small but ubiquitous. Keep copy minimal - one line and a clear CTA is all you have room for.
Most networks cap HTML5 banner file size at 150KB for the initial load. Keep animations lightweight, compress images, and defer any heavy assets. Google Display Network and DV360 have strict enforcement.
Campaign Builder generates HTML5 banners in all standard sizes from a single template. Change the creative once and export all sizes instantly - ready to upload to any ad network.
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