How to Optimize Your Campaign Images

OptinMonster makes it easier than ever to make sure you’re showing optimized images to visitors.

Optimized images are smaller in file size, which makes your campaigns and your site load faster and perform better.

Optimize Images

As of June 2020, all images uploaded to OptinMonster are automatically optimized using with no special steps required on your part.

Any previously uploaded images are not automatically optimized, however, we will be releasing an update in the future to optimize those images as well.


My images on Retina devices are blurry, why?

To ensure your images look sharp on retina displays, double the dimensions of the image before uploading to OptinMonster.

For example, if the image will be displayed at 500 x 500 pixels, you would want to set the image’s dimensions to 1000 x 1000 pixels using your photo program before uploading to OptinMonster.

What image size/dimensions should I use for my campaign?

Because your campaign can be fully customized in appearance and layout, we do not have specific image dimension recommendations. The exact dimensions will depend on your own campaign design.

To give some context that may be helpful – our campaign templates are generally between 550-750px wide, and the height is based on what content you put inside. For any images you create, you might create them to match that width if you would like them to show across the full width, or if you want to be extra sure they will appear crisp on retina devices, you can double the dimensions.

If your campaign is 600px wide, you would create an image that is 1200px wide for retina devices.

Our mobile templates are usually between 300-400px wide, to fit and look the best on smaller mobile screens.

You can also customize the width of your campaigns, which can impact how the image(s) within are displayed.

How do I find good images for my campaigns?

You can easily add Unsplash stock images to your campaigns, or see our post on places to find images for better conversions.

How do I disable Pre-loading of Images?

Preloading of images and web fonts does not happen by default, however, there are a few circumstances where it does happen since we cannot predict if a customer is going to trigger the campaign on their own, without our display rules triggering it first. The two areas right now are Exit-Intent and Monsterlinks.

Please be aware that the below code will also disable pre-loading of webfonts along with the images as there’s no way to disable them individually.

If you want to disable the preloading of images or web fonts, you can easily do that through Api.js:

document.addEventListener('om.Campaign.init.preload', function(event) {
    var campaign = event.detail.Campaign;
    campaign.settings.preload = false;

If you want to make sure it only happens for a specific campaign, that can also be done:

document.addEventListener('om.Campaign.init.preload', function(event) {
    var campaign = event.detail.Campaign;
    if ({slug} === {
        campaign.settings.preload = false;