How to Choose Correct Banner Dimensions for RTB Via Adform or DV360

We have prepared a guide on selecting the most suitable banners for RTB. If you haven’t been acquainted with Adform or DV360 yet, this article is for you. It will give you the main overview.

What are Adform, DV360 and RTB?

Adform and DV360 are platforms for real-time buying banner advertising (so-called DSP) on websites (RTB). It pays off especially in brand advertising. The goal is not an immediate return on investment, but an increase in awareness of your brand.

With RTB you have access to websites that are closed to you via classic PPC systems, and also to better targeting than offered by Google Ads and Sklik. At the same time, RTB is more flexible than buying directly on the web and you are not limited by the minimum investment amount. Another benefit is the ability to fully manage the performance of your ad.

Choose based on where you want to be seen

In RTB, more than anywhere else, you should first look at where you want your ad to appear and make banners based on that.

There are hundreds of dimensions you can create. Of course, some are displayed more, some less. We will focus mainly on the most commonly used ones. We intentionally omit small formats, because their readability is poor. 

The most common dimensions on Czech websites

There’s an infinite number of banner formats. Those that work best from our point of view are:

  • 160×600 px
  • 300×250 px
  • 300×600 px
  • 480×300 px
  • 480×480 px
  • 970×310 px
  • 970×210 px

Premium formats are also available at auction:

  • 2000×1400 px – Displays mainly on news and tabloid servers. It is highly clicked-through with a CTR of 0.8 — 2.5%.


  • 500×200 px (Mobile Branding) – This format is intended for mobile devices. In addition, it belongs to the less aggressive formats, because it is displayed at the bottom of the screen, but it still has a huge visibility. CTR is around 1.4 — 2.6%.
  • 720 × 1280 px (Interscroller) — It is the largest mobile format and guarantees 100% visibility. The advertising message is located in the background of the page, which is gradually revealed by scrolling. CTR is lower than mobile branding, around 0.95%. On the other hand, it is a format that is impossible to ignore.
  • 720 × 1280 px (Vignette) — This is the same size as the Interscroller. The main difference between these formats lies mainly in the way they are displayed. The vignette, unlike the Interscroller, appears when you click on the article and must be closed by physically clicking on the close button. CTR of this format is around 7.01%.  
  • Native format — This is a combination of an image and a text ad. It appears in the list of articles and the difference is that it is marked as an advertising message. In DV360 we are not limited to an image, but we can also use video for native formats.
  • Video banners — This type of banner contains partly a static message, the other part plays video. Take a look at the preview from Seznam.
  • Dimensions for DV360

  • Parallax — This is a full-page, highly interactive mobile format with the effect of multi-layer parallax animation, which blends when scrolling content on the phone. It is available in the format of 300 × 250 px.
  • Panorama — a mobile responsive interactive creative that contains three frames with content the user can flip between. In addition, it is data-based, so we can dynamically adapt the banner content to individual audiences and goals. 
  • Swirl (300 × 250 and 300 × 600 px) — 3D mobile format used to increase Brand Awareness and interest in purchasing the product. The user can utilize custom interaction in combination with various functions to examine the spatial banner, display text or 3D model, or expand the creative to full screen. Brands can tell an engaging story, but … 

You don’t have to have them all — choose the most suitable ones

We usually choose from these dimensions according to what the banners look like. The aim of display advertising is to convey our message in such a way that it is understandable, looks as good as possible and is impossible to ignore. Banners with small dimensions are easily overlooked, so it is better to choose larger ones.

What to do after we have chosen the dimension?

Another task is to create an engaging creative. Moving banners are the most effective. You can’t go wrong with Rich Media formats. The goal of display advertising is to engage users, and attractive appearance improves the impression of your advertising message.

Are you missing a capable graphic designer or programmer on hand to create such banners for you? At Adform, they thought of this possibility and prepared a simple studio for the production of various creatives. It takes a while, but it’s not that expensive and the animations look perfect. 

Dynamické reklamy

We’ve selected some other interesting formats to show below.

3D Cube

Creating such a cube is very simple, especially if you have banners that are already created. In Adform studio, choose 3D Cube 300 × 250 in the templates. The default size is 300 × 250 px, but you can easily change it in Banner settings and adjust the dimensions to 300 × 600 px, for example.

In addition, it is necessary to select Standard Format (the default setting is 3D Box MPU and it is not supported for some media houses, for example Seznam.). In the File Browser tab, load individual banners on each side of the cube.

Of course, you must not forget to set the Click tags in Banners setting so that the individual pages link to the correct pages. Finally, upload to Adform. During production, it is also necessary to think about the final size, because everything that is beyond the agreed size with Adform costs extra. We have created a cube for you to see as an example; click here to see it.


Carousel is a very interactive format, which is intended to arouse not only the intent to click, but also a certain playfulness. In addition, through statistics and heat maps, it is possible to monitor whether the banner really met the expectations, even if there was no direct click. Furthermore, we do not have to limit ourselves only to horizontal formats during production, but 300 × 600 px can also be used.



Venetian is one of the popular formats mainly because it is possible to convey more information on one banner or to display more product variants. Thanks to its movement, the banner stands out of the so-called banner blindness. Even with this format, you are not limited by dimensions.

HT_dveře Venetian

Dynamic ads

Dynamic ads are a new format that allows you to automatically generate banner text from a pre-prepared Excel file into templates that are then displayed to the most relevant audience. In addition to quick optimization, the advantage is also the creation of a large number of different banners with different graphics and text.

Dynamic Ads Showing Products from the Feed

This is a classic dynamic remarketing. The banner displays products that the user viewed on the website, put in the cart, but did not purchase it, etc. One great advantage is the ability to play with the creative, and thus get rid of the established templates offered by other systems.

Barbora Dlouhá

For our clients, I take care of programmatic display buying campaigns which takes place through an online auction. But the hammer I keep is only for my colleagues.