Ad File Size

...and why it matters

Malgorzata Pietruszka avatar
Written by Malgorzata Pietruszka
Updated over a week ago

When preparing your ads to launch a display ad campaign, you'll most likely focus on figuring out the right sizes - a list of specific combinations of height and width expressed in pixels.

This is a must as publishers won't accept any other combinations due to universal ad-slots requirements, but there's something else you should consider when creating visual ads - the ad file sizes.

File size (file weight) is a measure of space a computer file takes up on a storage medium, typically measured in bytes (B) which are the base unit of information and represented by larger units using prefixes like 'kilo-' (k), 'mega- (M), or 'giga-' (G).

Display ads file sizes are expressed with kilobytes (kB) or megabytes (MB), and their volume depends on the size of digital assets used in ad creation (images, logos, texts), and the pixel dimensions.

Why display ad file size matters

  • Ad file size affects the loading time of a website - the heavier the files, the longer it takes to load that web page

  • Ads loading too long affect the user experience on the website - users will not wait for an ad to load, and you'll lose the impression

  • Publishers may apply restrictions for maximum accepted banner file sizes - if your ad is too heavy, it won't be approved for publishing

  • As our analysis revealed, ads weighing more than 1 MB (1024 kB) and less than 30 kB have significantly lower CTR

File size group

Average CTR [%] - Desktop

Average CTR [%] - Mobile

Small (0-30 kB)



Medium (30-150 kB)



Large (150-1000 kB)



Extra Large (+1000 kB)



  • Smaller banners have a lower recommended maximum file size limit than bigger ones

Checking your file's size

  • Windows: Right click on the file / Properties / Details tab / See image dimensions for pixel size and file size

  • macOS: Control click on the file (click on the file while pressing and holding 'Control' key) / Get Info / Look for Size under 'General' section and Dimensions under 'More info' section

  • If you have already uploaded or created your ads on Match2One platform, you can check their sizes in Creative Studio - the file size information is visible next to the ad dimensions under the ad name and preview. Our platform will also warn you in case your ad's file size exceeds 1 MB (1024 kB)

How can you reduce ad file size?

  • Use PNG file format over JPEG if you're creating static ads - PNGs weigh significantly less than JPEGs

  • Use lower resolution images and logos to build your ads

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