Banner ad sizes that actually get used
Five sizes cover most of the web. And a sponsorship banner can skip the whole question.
Facts checked 6 Oct 2026 · by the AdSworn team
Google AdSense's guide to ad sizes names five top performers: 300×250 (medium rectangle), 336×280 (large rectangle), 728×90 (leaderboard), 300×600 (half page) and 320×100 (large mobile banner). If you buy display ads through a network, make those first. If you sponsor a page directly, the banner usually adapts to the article it sits in, so you send a headline, a line of copy and a logo instead of a stack of image files.
The five sizes Google calls top performers
| Size (pixels) | Name | Where it works, per Google's guide |
|---|---|---|
| 300×250 | Medium rectangle | Inside text, or at the end of an article |
| 336×280 | Large rectangle | Inside text, or at the end of an article |
| 728×90 | Leaderboard | Above the main content; on forums |
| 300×600 | Half page | Beside content; favoured by brands for visual impact |
| 320×100 | Large mobile banner | Phones: twice the height of the standard mobile leaderboard |
Google's reason is simple: these sizes have the most advertisers bidding for them, so a site that offers them fills more of its space. For an advertiser buying through a network, that means these are the sizes your ad will be eligible for most often.
Start with the phone
A 728×90 leaderboard doesn't fit on a phone. A phone screen is about 375 pixels wide, so the ad either shrinks to a mobile size or disappears. Check your analytics for how many of your readers are on phones; for most article sites it's a large share. Design the phone version first, then the desktop one. A message that only works at 728 pixels wide doesn't work for most readers.
- Keep the headline under about six words; it has to read at a glance on a small screen.
- One call to action, as a button, not a sentence.
- Text big enough to read without zooming. If you need small print, the ad is doing too much.
Why a sponsorship banner skips the sizes
Fixed sizes exist because networks swap thousands of ads in and out of the same slot. When you sponsor one page directly, there's one ad in one place, so it can be drawn to fit the page instead. An AdSworn banner is built from text: a headline of up to 60 characters, one line of up to 120, and an optional logo. It sits at the top of the article, sized to the column on every screen, and matches the text size of the page it's on.
That has a practical upside: no designer, no five exports, nothing that looks blurry on a sharp phone screen. How to write the words is in how to write a banner ad that gets clicked.
Which size should you make first?
- Buying through a networkMake 300×250 first. Google's guide says it tends to have the most advertisers behind it, so it's the size most sites will offer. Add 320×100 for phones and 728×90 for desktop headers.
- Selling space on your own siteOffer 300×250 inside the article and one header slot. Two well-placed slots earn more than six that nobody scrolls to.
- Sponsoring a page directlySkip sizes. Write the headline and line, and check the preview on a phone before you send it.
The 12 Best Online Video Editors of 2026 (Free and Paid)
- Banner ad$75 / 4 weeks
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What to put inside the banner
Size matters less than what fills it. Whatever the dimensions, a banner that works usually has the same three parts:
- Who you are, in one glance: a logo or brand name, small, in a corner.
- One reason to click, as the headline: what the reader gets, in their words. "Logos in 48 hours" beats "Creative excellence".
- One button with a verb on it: "See pricing", "Try it free". Make it look pressable.
Leave space around the words, keep the contrast high enough to read in sunlight, and keep image files light so the ad doesn't slow the page it sits on. If a banner needs a paragraph to make sense, the product needs a sponsored post instead; see banner ad vs sponsored post.
Then test it where it will run. Open the page on your own phone, scroll to the ad, and ask whether a stranger would understand it in two seconds. That check catches more problems than any size chart.
Straight answers
What is the most common banner ad size?
Google AdSense's guide to ad sizes says the 300×250 medium rectangle tends to have the most advertiser inventory, which makes it the safest first size to make.
What size is a leaderboard ad?
728×90 pixels. Google's guide says it performs well above the main content. It doesn't fit on a phone, so pair it with a mobile size such as 320×100.
What size should a mobile banner be?
320×100 is the large mobile banner Google lists as a top performer, twice the height of the standard 320×50 mobile leaderboard.
Do I need image files to sponsor a page on AdSworn?
No. You write a headline (up to 60 characters) and a line of copy (up to 120), and can add a logo. The banner is drawn to fit the page on every screen.