Let’s play a little old-school game – Spot the Difference! Take a look at the images below.
At first glance, the difference might seem simple: one is dull, and the other is bright. But from an SEO perspective, there’s so much more to it.
The first image? It’s unoptimized and has incorrect pixels, which could be a reason for your client site’s slumping SEO ranking. Using images like these could cost you 39% of your users.
On the other hand, the second image is fully optimized, and has the right size, quality, and attributes, giving your site a push in every possible way.
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Take a cue from Walmart—optimize images the right way—and you can experience a 30% boom in traffic, get a fair share of Google’s 22% traffic, and boost conversions by 25%.
The crux? Optimizing images isn’t just about aesthetics—it’s a key component of your SEO strategy.
So, buckle up as we will decode image optimization for WordPress featured images and other site visuals.
What are the Default WordPress Image Sizes
WordPress understands the critical role of properly sized images for performance and appearance, so it has predefined image sizes.
Here are the default WordPress image sizes:
- Thumbnail Size: 150 x 150 pixels and is used for gallery grids or small previews.
- Medium Size: 300 x 300 pixels (or a maximum width of 300 pixels) and can retain the image’s original aspect ratio. It is used within the context where larger but not full-size images are required.
- Large Size: 1024 x 1024 pixels (or a maximum width of 1024 pixels) and retains the original aspect ratio. This size is ideal for larger content areas.
- Full Size: The original size of the image used unchanged, allowing users to display images in their native resolution.
These default WordPress image sizes are incredibly versatile. From eye-catching WordPress featured images to sleek grids, these sizes help you optimize every image you use on a website, regardless of the WordPress version you’re using.
And, just in case you don’t know, WordPress 6.7 has some amazing media handling features to save you a great deal of time and effort in optimizing images.
Why Optimize WordPress Images?
Before we spill the beans on the importance of WordPress image optimization, let’s first understand what an optimized image actually means.
It means the image has the:
- Compressed file size to avoid unnecessary storage
- Perfect dimensions, scaled to fit exactly where it’s needed
- Appropriate format for high web performance
- Retina-ready resolution for crisp and clear display on any screen
By optimizing WordPress featured image size, you ensure that the image is adjusted to achieve the perfect balance between visual quality and file size. This translates to:
- Faster load times as websites using optimized images can lower their load time by up to 35%.
- Reduced bounce rate.
- Higher SEO ranking as optimized images helped the site to load faster.
- Saving 40-80% in image file size by utilizing Content Delivery Networks (CDNs).
Long story short, prioritizing WordPress image optimization is like hitting many birds with one stone as it improves load times, enhances user experience, boosts SEO rankings, and reduces bandwidth consumption.
So, if you’re still neglecting image optimization, wake up and start optimizing the WordPress featured image size, thumbnails, and every other image used.
Need a handholding in this? We have a detailed blog on WordPress image optimization.
What Impacts the WordPress Featured Image Sizes
The size of your featured image in WordPress can be influenced by several factors:
Theme Settings
WordPress featured image size mainly depends on the type of theme you’re using. Many themes have predefined image sizes for featured images, depending on the theme’s design and layout.
However, if you’re using a full site editing theme like Gutena, you can customize the WordPress featured image size and gain full control over it.
WordPress Default Image Sizes
As mentioned above, WordPress uses default theme sizes, which greatly influence the WordPress featured image size—especially if the theme you’re using doesn’t provide specific settings to override them.
WordPress Plugins Used
The kind of plugins you have installed on your WordPress site will also impact the featured image WordPress sizes. For instance, if you have image compressors like reSumsh.it or Imagify installed then they will auto compress the WordPress featured image size.
Similarly, the best WordPress caching plugins will store the different versions of the image and optimize it for different sizes and devices, resulting in better and higher load times.
Browser and Device
WordPress themes are designed to adapt to different screen sizes. This means that your WordPress featured image may appear differently on a desktop, tablet, and mobile devices.
In addition, different browsers might also interpret the WordPress featured image size and render it differently.
How to Customize WordPress Featured Image Sizes
While the default WordPress featured image sizes, landscape– 1200 x 900 pixels and portrait- 900 x 1200 pixels, work fine, they’re not always ideal for customized WordPress development.
Agencies often need to tailor the featured image sizes to match their clients’ unique design preferences.
Well, doing so is easy. Here are three ways.
Method #1: Customize WordPress Featured Image Size Through the Dashboard
- Open the WordPress Dashboard of the site.
- Go to Settings > Media in your WordPress dashboard.
- Find the default sizes for images such as thumbnail, medium, and large.
Enter the desired dimensions and click on ‘Save Changes’.
Method # 2: Editing functions.php to Register New Image Sizes
You can also customize the sizes of WordPress featured images, thumbnails, and other media files by editing the functions.php file (located in wp-content/themes/your-theme/).
- Go to WordPress Dashboard.
- Navigate to Appearance > Theme Editor.
- On the right-hand side, find and click on functions.php (located under Theme Files).
- Add the following code to register the custom size:
function custom_image_sizes() {add_image_size( 'custom-featured', 1200, 800, true ); // Example custom size}add_action( 'after_setup_theme', 'custom_image_sizes' );Doing so will register a custom image size called custom-featured with dimensions of 1200px by 800px.
- Update the file.
After registering the custom size, you can use it when displaying featured images or anywhere images are shown.
Method #3- Optimize WordPress Featured Image Size Before Uploading
You can use online photo editing tools like Photoshop or Photopea to customize the WordPress featured image size before uploading it to your website.
Next-Level Optimization with Modern Formats
Modern image formats such as AVIF and WebP are winning the WordPress image optimization race as they can compress the images up to a great extent while retaining the quality.
For starters, AVIF images are nearly 50% smaller than JPEG and PNG images, whereas WebP can reduce image sizes by 25-34%.
What’s even better is that WebP supports both lossy and lossless compression. The newly launched WordPress 6.7 supports these two image formats.
If you want to shift to AVIF or WebP from JPEG or other outdated image formats, using plugins like ShortPixel or Smush will automatically convert the images on your website—no need to manually convert each one.
If you’re using Apache servers that support WebP or AVIF, you can convert your website images by adding specific rewrite rules to your .htaccess file.
RewriteEngine On
RewriteCond %{HTTP_ACCEPT} image/webp
RewriteCond %{REQUEST_FILENAME} \.(jpe?g|png)$
RewriteRule ^(.+)\.(jpe?g|png)$ $1.webp [T=image/webp,L]
Alternatively, if you’re using a Content Delivery Network (CDN) like Cloudflare or KeyCDN, you can take advantage of their built-in support for WebP and AVIF. These CDNs can automatically serve optimized images based on the user’s browser and device.
Before jumping to these modern formats, keep in mind that not every browser supports them, especially AVIF, which is new and supported by Chrome and Firefox.
To be on the safe side, keep fallback options in place for browsers that don’t support these formats.
Automating Image Optimization
When the ideal practice is to use one image per 150-200 words, manual WordPress image optimization can be a daunting task for media-heavy websites like e-commerce stores, travel blogs, news websites, online magazines, etc.
Automating image optimization is the best solution, and here’s how you can make it happen:
- Install image scaling and resizing plugins like Insanity and Regenerate Thumbnails to automatically optimize images as they’re uploaded.
- Schedule bulk image optimization using plugins such as Smush and ShortPixel for media-heavy websites.
- Enable lazy loading through plugins like WP Rocket to delay off-screen images. Check out the video below to learn more about lazy loading
- Leverage WordPress’s built-in responsive image feature to automatically serve appropriately sized images for various devices.
- Combining image optimization with a CDN like Cloudflare or BunnyCDN will work like a charm when you want to distribute optimized images quickly across the globe.
Best Practices for Image Optimization
Want to up your WordPress image optimization game? Stick to these best practices:
- Use tools like TinyPNG, Smush, or ShortPixel to compress images without compromising quality, ensuring faster loading and reduced server storage.
- Scale images to fit the exact display requirements so the browser doesn’t resize them, maintaining the visual consistency of your website across devices.
- Select the right image format: JPEG for detailed photographs, PNGs for graphics, and WebP for lightweight images.
- Activate lazy loading to reduce initial load time and boost page speed as images appear in the user’s viewport.
- Write clear, keyword-focused alt texts for each image. This improves both accessibility and SEO rankings.
- Set up browser caching so visitors’ browsers can store images locally, reducing the need to reload them when users return to your site.
- Use descriptive, SEO-friendly file names for images to help with search engine rankings and maintain a cleaner media library for easier management.
- Serve images through CDNs like Cloudflare or KeyCDN for faster delivery and reduced server load, especially for global audiences.
Wrapping Up
Your website’s images can be the heroes or villains of your digital story, depending on how you prep them. As images account for up to 75% of your website’s weight, leaving them unoptimized is like carrying a fully loaded backpack on a marathon—you’ll slow down, tire out your server, and risk losing your audience.
So, make sure that your WordPress featured image size, header image size, and all the media file sizes are well optimized. Don’t let slow images hold your site back—optimize them, and let your website run at its full potential!
FAQs
Why is image optimization important for WordPress?
Image optimization means reducing and compressing image size without compromising quality. This is crucial for improving website performance, as unoptimized images can slow down your page load times.
What is the ideal WordPress featured image size?
The ideal WordPress featured image size is between 1200px and 2000px, but it also depends on the WordPress theme you’re using. You can customize the WordPress featured image size based on your site’s needs.
What are modern image formats?
Modern image formats, such as WebP and AVIF, offer better compression and smaller file sizes compared to older formats like JPEG and PNG.
How can I automate image optimization in WordPress?
You can automate image optimization in WordPress using plugins like ShortPixel or reSmush.it. These plugins automatically compress and optimize images as they are uploaded to your site.
How can I optimize WordPress images in bulk?
You can optimize images in bulk with the help of image compressors like ShortPixel or EWWW Image Optimizer. For large-scale image optimization, you can use the WP-CLI tool to enable batch processing.
