Hello! We’re John and Brian, and we’ve been designing websites for small businesses from our office in Preston, Lancashire since 2009. “Banner” is one of those words that gets used for several different things, so here’s a plain-English answer to “what is a web banner?”, followed by the main types, standard sizes and the advantages of banner ads.

What is a web banner?

A web banner is a wide, usually horizontal graphic on a web page that grabs attention and points people towards something. The term is used in two main ways:

A banner on your own website: for example, the large image and headline at the top of your homepage (often called a hero banner), or a slim strip across the top of the page announcing an offer.
A banner ad: a paid advert, made up of an image, a short message and a link, shown on other people’s websites and apps to bring visitors back to yours.

Both do the same basic job: they catch the eye and prompt people to take the next step.

What is a banner on a website?

On your own website, you’ll usually see one of these:

Hero banner: the large, eye-catching area at the top of a page, combining an image or video with a headline and a call to action button.
Announcement or promo bar: a narrow strip, usually right at the top of the page, for things like a sale, a discount code, free delivery or holiday opening hours.
In-page promotional banner: a block part-way down a page that promotes a product, service, event or mailing list sign-up.

You’ll also see cookie banners, which ask visitors for consent to cookies. They’re there for legal reasons rather than marketing, so they should be clear and simple, not designed to push people into clicking “accept”.

What is web banner advertising?

Web banner advertising (also called display advertising) means paying for your banner to appear on other websites and apps. The best-known example is the Google Display Network, which you can use through Google Ads. Banner ads are often used for retargeting: showing your advert to people who have already visited your website, to remind them to come back and buy or get in touch.

What size should a web banner be?

For banner ads, there are standard sizes. These are some of the most common sizes listed in Google Ads’ specifications for uploaded display ads:

Name	Size (pixels)	Where you’ll usually see it
Leaderboard	728 × 90	Across the top of a desktop page
Large leaderboard	970 × 90	Across the top of a desktop page
Billboard	970 × 250	A larger strip at the top of a page
Inline rectangle	300 × 250	Within or beside content
Large rectangle	336 × 280	Within or beside content
Half-page ad	300 × 600	Down the side of a page
Wide skyscraper	160 × 600	Down the side of a page
Mobile banner	320 × 50	Phones
Large mobile banner	320 × 100	Phones

Uploaded image ads need to be GIF, JPG or PNG files of 150KB or less, and any animation must stop after 30 seconds. Google’s responsive display ads work differently: you upload images, logos and text, and Google builds adverts to fit the available space.

Banners on your own website don’t have one standard size, because they need to work on every screen from a small phone to a wide monitor. In practice, we design them to be responsive: we prepare a wide, well-compressed image, keep the important part of the picture away from the edges so it still works when it’s cropped on a phone, and use real text for the headline and button rather than text baked into the image. Real text stays sharp, can be read by screen readers and search engines, and is easy to update.

What are the advantages of website banner ads?

They attract attention. A banner at the top of the page is one of the first things visitors see. Designed in a colour that contrasts with the rest of your page, it’s hard to miss, so people won’t overlook your offer or discount code.
They suit almost any website. Banners work for online shops and service businesses alike, and visitors already know how they work.
They prompt action. A banner with a clear offer and a single call to action gives people a reason to act now. If you use a countdown or a deadline, make sure it’s real: fake urgency can mislead customers and break UK consumer protection law.
They’re cost-effective. Banners are quick and straightforward to produce compared with video adverts, and easy to update when your offer changes.
They’re measurable. You can track clicks and enquiries from a banner, then tweak the wording or image to see what works better.

Tips for banners that work (and don’t annoy)

Stick to one message and one clear call to action.
Keep the wording short enough to read in a couple of seconds.
Make sure text has strong contrast against its background.
Avoid large pop-ups that cover your content, especially on mobile. They frustrate visitors, and Google advises against intrusive interstitials.
Keep file sizes small so your page still loads quickly.
Check how the banner looks on a phone before it goes live.

Website banner FAQs

What’s the difference between a banner and a hero image?

A hero image is the large picture at the top of a page. A hero banner is that image combined with a headline and usually a button. People often use the terms interchangeably.

What is the most common banner ad size?

The 300 × 250 rectangle and the 728 × 90 leaderboard are two of the most widely used sizes, with 320 × 50 a common choice for mobiles.

Are banner ads still worth it in 2026?

They can be, particularly for retargeting people who already know your business. Results vary a lot by industry and budget, so start small, measure the enquiries or sales you get, and adjust from there.

Need a banner or a better homepage?

If you’d like a hand designing banners for your website, or a website that turns more visitors into enquiries, give John and Brian a call on 01772 822626 or get in touch online. You’re welcome to pop into our Preston office for a coffee too. You can see examples of our work in our case studies.

What is a website banner? Types, sizes and advantages of banner ads