After discussing the image format for email campaigns in a previous article, we’re returning to this topic with the equally important subject of image size. Why? Simply because an email can be perfectly designed with stunning visuals; but if it’s too heavy, your efforts are unlikely to pay off. So how do you find the right balance so your images enhance your messages rather than detract from them? This article guides you through essential practices to optimize their weight while maintaining their visual appeal.
The Heavier It Is, The Longer It Takes: The Need for Optimization
A common scenario we’ve all experienced at least once: you receive a newsletter or another such email, click to view it, and then… Several seconds pass before it displays correctly. A situation that can slightly annoy, or even discourage, a reader from engaging with the content.
We know it all too well: sending emails with too heavy images can slow down message loading times, frustrating users in the process, thereby reducing the effectiveness of your campaigns. Internet service providers and email programs have strict limits on the size of emails they accept. Exceeding these limits increases the risk that your communications are marked as spam, highlighting the importance of optimizing your images.
Ideal Image Sizes
What Weight?
Each image in an email should ideally not exceed 100 to 150 KB. This size strikes a balance between visual quality and loading speed.
Be aware, however, that this weight can be adjusted based on the number of visuals contained in the message, as a total weight of 800 KB maximum is recommended for all images combined.
What Resolution?
For emails intended to be read on screens, a resolution of 72 ppi is generally sufficient. This resolution is standard for web images and ensures your visuals are clear enough without being unnecessarily heavy.
However, with modern screens having higher pixel densities, such as Apple’s Retina displays, you might consider a resolution of 144 ppi to maintain increased sharpness without excessively increasing file size.
RGB vs CMYK
RGB (Red, Green, Blue) is the color space used for all images intended to be displayed on electronic screens like smartphones and tablets. In contrast, CMYK (Cyan, Magenta, Yellow, Black) is a color space primarily used for printing.
The choice between the two can significantly impact the file size. By opting for RGB, you not only reduce the weight of the visuals, but also ensure that their display remains faithful across all types of devices. For emails, it is therefore recommended to avoid CMYK to maintain fast loading times and a good user experience.
Optimizing the Weight of Your Images
Compress the Images
Use image compression tools that reduce file size without significantly altering visual quality. Platforms like ezGIF, Pixelhunter, or ImageOptim are perfectly suited for this task.
Choose the Appropriate Format
JPEG is ideal for photos with many details and colors, while PNG is better if you need transparency or a high level of detail. GIF, on the other hand, is perfect for animated images or simple visuals with a limited color palette.
Be cautious, however, as PNG and GIF are formats that are generally very large.
Correctly Size the Images
Before adding an image to an email, ensure its dimensions match the available space. Resizing an image to be smaller before sending can significantly reduce file size.
Use URLs for Large Images
Rather than embedding large images, consider hosting them online and providing a link in your email. This reduces the size of the message and also allows you to track clicks on the images.
Quality Above All
While image size is important, never excessively compromise on quality. A low-quality visual can harm the public’s perception of your brand. Be sure to test different compressions to find the best compromise between size and quality.
Optimizing image weight in your email campaigns is not just a technical concern; it’s a crucial component of your digital marketing strategy. By respecting size limits and preserving visual quality, you ensure an optimal user experience, thereby increasing open rates and click-through rates.
