Optimal Image File Sizes on Emails

[Lucho_Soto]

Hello everyone,

I have a best practice question about coding images in emails. My previous manager taught me to keep image file sizes at 50kb or lower per image to account for leads with slow internet connections. Our target market is Pre-K school systems so they don't tend to have the fastest internet. Unfortunately, keeping image sizes under 50kb is also time-intensive as it requires slicing large images into several pieces and arranging them in tables.

In your experience do you have a size cap on email images and if so what is it? Any thoughts on this would be greatly appreciated!

[Phillip_Wild]

Hi Lucho

Ideally you would A/B test it. You're right, it totally depends on the audience, internet connections and so forth. If your users are predominantly desktop, it won't be an issue. But most customers these days are opening many, if not most, of their emails on mobile.

I try and keep each image under 50kb by saving them out as 80% quality JPGs in Photoshop. Our entire weekly newsletter is around 200kb in total. Whether this is optimal - who knows - but in general, lower file size is better.

Test away and see if it makes a difference in engagement!

[Anonymous · Accepted solution]

The lighter the email (the images) the better. Especially when targeting schools which have slower internet access (colleges and universities are the exception).

Most images should be under 10kb. And don't have too many.