To maximize visitor engagement and conversions, your page needs to load in less than 2-3 seconds. And since so much visitor traffic now originates from cell phones, often on lower bandwidth 3G connections, it’s important to optimize your images.
In 2018, the median website page size was approximately 2.1 Mb. And the average page size was much higher.
Here are 5 ways to reduce image file sizes to reduce your page size and improve your page load speed:
TinyPNG is a web-based tool that uses lossy compression techniques to reduce the file size of your PNG files. By selectively decreasing the number of colors in the image, fewer bytes are required to store the data. The effect is nearly invisible but it makes a very large difference in file size, with size reductions up to 70% or more.
Remember: PNG file formats are best used for logos, line art, and icons with transparency; photographs should generally be saved as compressed JPGs.
- Adobe Photoshop, Elements
Graphics editing software allows you to custom crop and/or scale images to their actual visible dimensions. Plus, these tools provide a ‘Save For Web’ or Export option that allows you to reduce file sizes for web use thru compression. A compression (‘quality’) setting of 50%-60% of the original image is often sufficient to reduce file size and retain image quality. An advantage of using these tools is that you can also perform color and lighting corrections.
If your organization cannot afford Photoshop, Elements provides most basic image editing tools; GIMP is a cross-platform open source alternative available for free.
- File Explorer (Windows)
This is a quick method that allows you to send images at smaller dimensions. Right click any image and select “Send To: Mail recipient.” A window should be generated giving you the ability to send the image(s) from Smaller sizes (640 x 480 pixels) up to Large size (up to 1280 x 1024). With the exception of full width or super wide panorama header images, most images on your website should not need to be wider than 1,280 pixels.
- Cell phone
If the images are accessible on your cell phone, both iPhones and Android give you options to ‘Reduce image size’ when forwarding images.
When you upload an image to your Media Library, by default, WordPress creates 3 physically different, proportional versions of your image: thumbnail, medium, and large sizes. (These default image dimensions need to be adjusted to coordinate with your theme layout) Be careful inserting full-size images into your website.
You can further reduce image sizes with WordPress Plugins – such as EWWW Image Optimizer, Smush, TinyPNG. My favorite web host, SiteGround, even includes an image optimization option with its SG Optimizer performance Plugin.
And, if your WordPress Theme supports it, WordPress 4.4 added native responsive image support by including
sizesattributes to the image markup it generates. Browsers can now choose to download the most appropriate size and ignore the others — potentially saving bandwidth and speeding up page load times in the process.
UPDATE: WordPress 5.3 introduced a native feature that limits the maximum dimension of uploads to 2,560 pixels.