Most guides to banner ad sizes list a dozen formats and stop. That is fine if you buy ads. If you sell space on your own site, the question is different: which sizes will you accept, and where do they go?
A sponsor needs an answer before they brief a designer. Send them the wrong size and you either squash it into a slot it was not built for, or you ask them to start again.
This is the website banner ad sizes guide for the person selling the slots.
The sizes WB Ad Manager knows about
The plugin names a set of standard formats, so you can pick one instead of typing pixel values.
| Format | Size (px) |
|---|---|
| Leaderboard | 728 x 90 |
| Large leaderboard | 970 x 90 |
| Banner | 468 x 60 |
| Mobile banner | 320 x 50 |
| Mobile large banner | 320 x 100 |
| Medium rectangle | 300 x 250 |
| Large rectangle | 336 x 280 |
| Skyscraper | 160 x 600 |
| Wide skyscraper (half-page) | 300 x 600 |
| Square | 250 x 250 |
There are two more choices. Responsive fills any slot, and Custom size lets you enter your own width and height. If a custom size matches a standard one exactly, the plugin treats it as that format.
Which size goes where
Each placement has a list of sizes it is designed for. The ad editor uses those lists to match a fixed-size ad to compatible placements, which helps keep a 728-pixel banner out of a narrow sidebar.
| Placement | Sizes it is designed for |
|---|---|
| Header | Leaderboard, large leaderboard, banner |
| Footer | Leaderboard |
| Before or after content | Leaderboard, medium rectangle, large rectangle |
| After a paragraph | Medium rectangle, large rectangle |
| Sidebar widget | Medium rectangle, skyscraper, wide skyscraper, square |
| Before or after the archive list | Leaderboard |
| Sticky bar | Mobile banner, mobile large banner |
| Popup | Medium rectangle, large rectangle |
| Comments | Medium rectangle |
| bbPress forums | Leaderboard, medium rectangle |
| BuddyPress activity feed | Medium rectangle |
Responsive ads suit every placement. The shortcode placement is for responsive ads only, because the container is yours to control.
Mobile banner ad sizes
Phones need their own sizes. A 728 x 90 leaderboard is wider than most phone screens, so it will not fit a mobile layout.
The plugin names two mobile formats: the mobile banner (320 x 50) and the mobile large banner (320 x 100). The sticky bar placement is designed for exactly these two, which is why a desktop creative sent for that slot will not work. If you sell the sticky bar, say on your rate card that it takes a 320 x 50 or 320 x 100 file.
A medium rectangle (300 x 250) also fits on a phone, since it is narrower than the screen, and it can sit in the content or after a paragraph. For everything else, a responsive ad adapts to the slot, which is the easiest route when a sponsor cannot supply a separate mobile file. Whatever you accept, open the page at phone width before you publish and check that nothing is cut off.
Choosing sizes to sell
Do not offer every size. A short list is easier to sell and easier to design for.
Think about it from the sponsor’s side. A medium rectangle (300 x 250) is listed for more placements than any other fixed size: in the content, after a paragraph, in the sidebar, in popups and in comments. A sponsor who builds one creative at that size can run it in most of your slots.
A leaderboard (728 x 90) suits the top and bottom of a page and the archive lists. It is wide, so it works on desktop layouts and not on narrow ones.
The sticky bar on mobile is designed for the two mobile banners. If you sell that slot, say so on your rate card, because a desktop creative will not fit.
A sensible starting menu for a small site is two sizes: one medium rectangle for in-content and sidebar slots, and one leaderboard for the header. Add others when sponsors ask.
Fixed size or responsive
In the ad editor, the Sizing box has two options.
- Responsive fills any slot. The plugin’s own note says it suits AdSense auto and fluid HTML.
- Fixed size has a known width and height, and matches only compatible slots.
Under Fixed size there is a Format dropdown, which includes an option to auto-detect from the image. We suggest you pick the format yourself when you create an ad. It takes one click, and it means you know which placements the ad will match before you publish.
Image ads usually have a known size, so Fixed size fits sponsor banners. Use Responsive for network tags such as AdSense, where the network chooses the size.
What to send a sponsor
Put these on your “Advertise with us” page or in your booking email. Sponsors should never have to ask.
- The exact pixel sizes for each slot you sell, such as 300 x 250 for the sidebar and 728 x 90 for the header.
- A file size cap you are comfortable with. Heavy creatives slow your pages, and your readers feel it.
- A destination URL, which the plugin tracks clicks against.
- Alt text for the image, since image ads have an alt text field.
- Start and end dates, which you will set on the ad.
- A mobile version, if the slot shows on small screens and your layout needs one.
Keep the list short. A sponsor who gets a clear spec sheet tends to send a creative that works the first time.
After the creative arrives
Open WB Ad Manager > Add New Ad, upload the image, set the Sizing and Format, tick the placement, and set the dates. Then check the page at phone width, because a banner that fits a desktop sidebar can look different on a narrow screen.
Our walkthrough on placing your first ad zones covers the placements in more detail. If you are building a rate card around these sizes, how to sell ad space on your website covers pricing and booking. And if you run AdSense in the same slots, AdSense and direct sponsors in the same slot explains how they share it.