No matter what type of website you have – optimized images and images are essential to maintaining user engagement and improving performance. The goal of image optimization is to reduce the file size of images without sacrificing their quality. As a result, they consume fewer resources, load faster, and have a positive impact on SEO.
In this guide, we’ll cover everything you need to know about image optimization, including tips on how to do it and tool recommendations.
What is Image Optimization?
Image optimization is the process of adjusting high-quality web images to use the appropriate format, dimensions, and resolution while keeping the files as small as possible. It involves optimizing image file sizes, aspect ratios, formats, and more. Optimizing and adjusting images improves website performance and rankings.
Images play a vital role in enhancing the visual appeal of your website and increasing user engagement. However, large image files can significantly slow down your site’s performance, leading to a negative user experience.
Optimizing images for your website is essential to providing a seamless experience for your users while ensuring efficient bandwidth usage and improved search engine optimization (SEO). Here are some of the top reasons why optimizing the images on your website is so important:
a. Improved Page Load Speed
Optimized images are smaller in size and use less bandwidth, reducing the time it takes for your website pages to load. Faster page load times contribute to a better user experience, resulting in higher conversion rates and increased revenue.
b. Better SEO Performance
Search engines, like Google, reward websites with faster load times by ranking them higher in search results. Optimizing images can significantly improve your website’s SEO performance and visibility, attracting more organic traffic.
c. Reduced Bandwidth Consumption
Optimized images use less bandwidth, saving you money on hosting costs and helping you stay within your hosting plan’s limits. Additionally, users with slower internet connections or limited data plans will appreciate the reduced data usage.
d. Improved User Experience
Images are a critical component of website design, and optimized images ensure that your website looks sharp and professional on devices with a variety of screen resolutions. By optimizing your images, you can ensure that users have a visually appealing and smooth experience when browsing your site.
Why is Image Optimization Important?
Optimized images help improve your website’s speed and overall performance, including its SEO rankings and user experience. Let’s take a closer look at the benefits of image optimization.
1. Better Resource Usage
Large images take up more storage space and require more bandwidth to successfully transfer files to the user’s web browser. If you run a website with limited resources, you need to find ways to maximize the limited disk space that you have.
With image optimization, small website owners can significantly reduce the amount of bandwidth and disk space required to display and store their images. Visitors to your site will also benefit from this, as optimized images will help reduce page load times.
Another benefit of having a lighter website is that the time it takes to back up your site will be significantly reduced.
2. Higher Rankings
Google has made page speed a key component of its ranking algorithm, favoring websites that load quickly and penalizing those with slow speeds. Websites with optimized media files will load pages faster – giving them a better chance of being found in Google Image Search. To test your site speed, use a free tool like Google PageSpeed Insights.
3. Improved User Experience
Another major benefit of image optimization is improved user experience. Combining fast page loads and easy navigation, visitors to your site are more likely to stay longer to learn more about what you do, create, and offer.
The process of image optimization includes adding alt text to your images, which improves site accessibility – we’ll cover this further in the article.
How to optimize images for a website?
In this section, we’ll cover some of the aspects you need to consider when optimizing your images, such as image format, file size, resolution, and more.
1. Choose the Right File Format
Image format is the first aspect to consider when optimizing images. Before we break down the different image formats, it’s important to note that they are classified into vector and raster images.
Vector file formats include SVG, PDF, EPS, and AI. Vector images typically work well for depicting images that are a combination of lines, dots, and colors, such as logos and icons. The main advantage of vector images is that you can scale them without sacrificing quality.
Meanwhile, raster images are pixel-based, which makes them resolution-dependent. This means that raster images lose quality, becoming blurry or pixelated when resized. Image file formats in the raster category include JPEG, PNG, GIF, and RAW.
Let’s take a look at the most common file formats that work well in almost all browsers and can be edited in most image editing software.
a. JPEG
Especially the most popular image file format, JPEG, is supported by almost all devices and operating systems. Since JPEG images are relatively small, they don’t slow down web page loading times and are faster to upload or transfer.
Basic and progressive JPEG files are also excellent at preserving colors. However, since JPEG uses lossy compression, the smaller the file size, the lower the image quality. That’s because each time the JPEG format is edited, it loses more data.
Therefore, this format won’t work well for images that require continuous adjustments and contain text – it will be difficult to read after reducing the file size.
b. GIF
GIF files are 8-bit images that display a maximum of 256 colors. This means that GIF image quality is not as sharp as other raster formats. While GIF is not the right format for higher-quality images with a wide color range, it does support transparency, simple line drawings and text, and produces small file sizes.
GIF is the best image format for creating animated images, which is a great way to create engaging content. Images in this format load quickly and use less bandwidth, making it a great alternative for sharing simple images in banner ads, blogs, and social media.
Popular websites like Make A Gif and Giphy allow you to easily create GIFs and store them all in one place.
c. PNG (Portable Network Graphics)
Another popular file format for website images is PNG. PNG files can have up to 256 colors and support partially transparent images, capturing color information more efficiently than GIFs and displaying higher quality than JPEG images.
If you need to create or store images such as logos, icons, simple illustrations, or anything else that requires smooth transitions between colors, PNG images are a great choice.
Additionally, PNG format works well for text-heavy images such as screenshots, infographics, and banners. However, since this file format is larger than JPEG, using too many PNG files will slow down your page load time.
d. WebP
As a solution to improve lossless and lossy image compression, Google developed this image format. WebP combines characteristics of other popular web image formats, such as replacing GIF for animation and PNG for transparency.
Unfortunately, some CMS (Content Management Systems) platforms do not support the WebP format. However, for users running WordPress sites using WordPress 5.8 or higher, WebP images can be uploaded to the media library.
To automatically convert images in your media library to WebP format, you will need to install a plugin such as ShortPixel or Optimole.
2. Compress Your Image Files
When compressing image files, it is important to remember that smaller file sizes usually result in lower image quality. Image compression not only reduces storage and bandwidth usage, but also provides faster page loading and download times for site visitors.
However, you need to consider image content, color gradients, and the complexity of detail details when choosing how to compress images for websites without sacrificing quality. The advantage of choosing raster files over vector images is that you can use either lossy or lossless compression techniques with raster images.
When you use lossy compression, some data is removed from the image, resulting in a smaller file.
On the other hand, lossless compression does not affect the quality or clarity of the image because it only removes non-essential data. If you need to use high-quality photos on your website, lossless compression is likely your best option, even if it means slightly longer loading times.
Some image editing programs, including Adobe Photoshop, come with image compression tools. When compressing your images, be sure to implement the following best practices:
- Compress images before uploading. It’s best to compress images before uploading them to your site. This helps you save disk space and speeds up the upload process.
- Automate the image compression process. If you’re dealing with a few images, automatic compression may not be a priority. However, it’s a great alternative when you need to compress a large number of images at once – saving you a lot of time. Automation is also useful for compressing images into different formats and naming files.
- Adapt image compression to your device. Make sure to use the right compression format based on the targeted device. For example, lower resolution images may still look good on mobile devices and help improve the user experience on your website.
Another option is to remove the background API to maximize file size without losing quality. For existing images on your site, testing tools like GTMetrix will help identify which images need to be optimized.
For existing images on your site, testing tools like GTMetrix will help identify which images need to be optimized.
Pro Tip
To save even more storage space, check your site’s media library to remove unused images. If you’re using WordPress, a plugin like Media Cleaner can help make the process more efficient.
3. Use Appropriate Image Dimensions
Image size and image dimensions are two different things. The former refers to how much storage space an image takes up on your website – image file sizes are usually measured in KB (kilobytes) or MB (megabytes).
Image dimensions, on the other hand, refer to the width and height of an image in pixels. Using images with the wrong dimensions is an inefficient process and will slow down your website’s loading speed.
For example, if you use a 500 x 500px image for a 50 x 50px thumbnail, the browser will have to download and scale the image correctly before displaying it to your site visitors. The best way to avoid this is to serve scaled images . Scaled images adjust to the exact dimensions required by the website, whether it’s a full-width image or a small thumbnail.
To resize images to better fit your site, you can use offline tools like Adobe Photoshop and GIMP or an online image editor like PicResize.
While it’s possible to crop images using the WordPress media library or other built-in tools, doing so before uploading them to your site will avoid creating multiple versions of the original image and taking up additional disk space.
You can use your browser’s Inspect tool to find out the maximum display size of an image. Alternatively, there are several page ruler browser extensions you can install to measure various elements on a web page.
However, using a plugin may be a better alternative for websites with a lot of images – we’ll list the best image compression and optimization tools later in the article. If you’re a tech-savvy user, take advantage of your browser’s built-in developer tools.
4. Consider Serving Images via a CDN
Using a content delivery network (CDN) to serve static content can significantly improve the performance of your website. Instead of relying on a single server to transport megabytes of data for each visitor, a CDN provides global reach thanks to its network of data centers.
A CDN caches the requested content and then delivers it from a geographical location closer to the website visitor. This means the data travels a shorter path, leading to faster loading times for your website and all its media content.
Without optimizing your images, a CDN already speeds up page load times. In addition to a regular CDN, you can also use an image CDN . It can offload your site’s images by up to 80%, resulting in a significant increase in loading speed and no noticeable loss in image quality.
An image CDN can work well if you run a dynamic website like an eCommerce store or frequently upload new images. Some of the most popular image CDN providers include Cloudflare , Fastly CDN , and ImageKit .
Apart from greater scalability and efficiency, let’s take a look at more benefits of using an image CDN:
- Improved user experience. An image CDN automatically minifies images, converting their format according to the user’s device and the image content. This is especially useful when accessing sites like eCommerce stores, which may display multiple thumbnail images on each web page.
- Improved site speed. As long as your web images are stored in an image CDN, they don’t need to be optimized every time a new device requests to load them. This is because the CDN server uses caching, speeding up the time it takes to deliver images.
- Mobile-friendly. Advanced image CDNs ensure that your images display correctly on all devices. To improve image quality, an image CDN adapts and compresses images according to the user’s device and network conditions.
- Constant uptime. Image requests are usually served with the latest cached data. If the CDN server is down, the page will still load normally.
With all the advantages of serving images via a regular or image CDN, there is still one downside – SEO.
If you use a CDN, from a search engine’s perspective, the images are technically not part of your website because they are physically located somewhere else. To avoid this, enable the CDN on a subdomain. That way, the SEO value of the images will still be directed to your site.
What is the best image size and quality in blog post?
You typically have a few options when it comes to image width and quality when using image optimization tools. Image width or resolution determines the amount of detail an image has. Different parts of your website have different scaling requirements for optimal display. Images that are too large can take up unnecessary memory, slow down page load times, and ruin the visual design of your website.
Image quality, meanwhile, determines the percentage of compression applied to the image file. The higher the percentage, the less detail the image loses. Ideally, your images should be medium quality, between 80% and 90%. This range of quality levels minimizes your image files while maintaining their visual quality.
Image width and quality affect the user experience of your website across devices. For example, a high-quality 1920×1080px image might look great on a desktop device, but be cropped or squeezed and load slowly on a mobile screen.
2500px is the ideal image width for most browsers. It can fill the entire screen without the risk of being cut off or appearing pixelated.
How to optimize images for better SEO performance?
Well-optimized images give your website a better chance of appearing in search engine results. Using the right combination of formatting, alt text, and titles can contribute to improved SEO performance.
You don’t have to spend a lot of time formulating and executing a complicated SEO strategy to optimize your images. Improving your SEO performance through image optimization involves a few easy steps. Let’s take a look at some image SEO factors to focus on so search engines can crawl, index, and rank your images more efficiently.
1. Write Proper Image File Names
Descriptive file names help you and search engines like Google find your images quickly. That’s because properly named files provide context about the image, increasing its chances of ranking in image searches.
Using the default name your camera gives each image is not a good practice. Google’s bots won’t be able to tell a lot of images with the name shoes-image-01 . A more appropriate and descriptive file name would be nike-tanjun-shoes-pink-white.
Depending on the type of image you’re creating or saving, be sure to include the product name and descriptive words like the brand or color. Also, use hyphens instead of underscores to name your files. For example, use white-shirt.jpeg instead of white_shirt.jpeg.
If you’re serving an international audience and translating your site’s images, don’t forget to translate the filenames as well. For keywords, use a tool like Google Search Console to review your Search Analytics and queries that include your products.
This will help you find out what customers would type into a search engine if they were looking for the type of item you offer. However, be careful not to stuff it with keywords. Only use ones that fit the context and describe the image naturally.
2. Write Alt Text
Adding alt text is another technique to optimize your images and improve SEO. Essentially, alt text is a description of the context and content of the image. It’s what screen readers read and what will appear on the page if the image can’t load.
In 2021, 26% of all images on the top 1 million websites did not have alt text. In addition to improving accessibility and SEO, adding it will also give you an edge over your competitors.
There are a few practices to follow to write good alt text:
- Be very specific. Make sure your description is as specific as possible, including the image’s message, context, etc. However, note that you do not need to describe images that are used for decorative purposes.
- Keep it short. Try to keep your description within 125 characters. Note that you do not need to mention “image,” “photo,” or anything like that in your alt text because the HTML code already covers it.
- Use keywords. If possible, include your target keyword in the alt text. However, be careful not to overdo it.
3. Use Structured Data for Your Images
Another strategy to maximize the impact of your SEO efforts is to utilize structured data or schema markup for your WordPress site. Essentially, it offers clear information about your page to help search engines fully understand its purpose and context, improving the crawling and indexing process.
That’s because structured data provides additional information about an image, helping search engines associate it with a specific search query, such as product details or even price. By using structured data on your images, you increase the chances of them appearing in search results.
You can use Schema.org to structure your data to improve your site’s SEO performance. This collaborative vocabulary helps you find specific markup for your pages and code it correctly.
If you’re a WordPress user, plugins like All In One Schema Rich Snippets and Schema simplify the process of adding structured data to your website.
Additionally, it’s important for site owners to follow all of the general structured data guidelines that Google has set forth. If you fail to implement these standards, you could be penalized with poor rankings, or your pages could be ineligible for rich results.
Tools like the Rich Results Tester and URL Inspection Tool help you check for issues with your structured data. In addition to images, structured data can be used for a variety of purposes, including:
- Knowledge graph. When you search for a person or business, Google collects information from various websites and sources to show more relevant and useful results. Add information about your website to the Google Knowledge Graph through structured data.
- Rich results. If your website contains multiple items that match a particular search query, Google may display richer preview results by displaying product reviews, star ratings, or videos. Rich results are a great opportunity to attract more targeted users to your page.
- Accelerated Mobile Pages. The main goal of Google’s AMP project is to improve the user experience on mobile devices, such as providing pages that load quickly. Using structured data in AMP can make your website appear in mobile searches as part of rich results and carousels .
4. Optimize Page Titles and Descriptions
When ranking images, Google also considers components like the page title, meta description , headers, and content. Therefore, optimized page titles and descriptions can help you rank in image search. Doing keyword research is a good place to start.
Tools like Ahrefs , Ubersuggest , and Semrush can help you identify the most relevant search queries, their search volume, and keyword difficulty. Then, include relevant keywords in your page titles, meta descriptions, and URLs. Combined with other image optimization strategies, this will increase your site’s chances of ranking high in search results.
5. Place Images Correctly
Another important aspect of image optimization is the placement of images on your website. Adding images haphazardly can have a negative impact on the context and relevance of your page.
While it’s not uncommon to use images to break up long stretches of text, they should be directly related to the written content. Keep in mind that screen readers can’t access text within images, so be sure to provide relevant alt text and include important information within the image only.
In addition to improving accessibility, this also helps improve the visibility of your page on Google image search.
6. Optimize for Mobile
Given that more than half of all web traffic comes from mobile devices, it’s easy to see the importance of ensuring that visitors can seamlessly access all pages and images from all devices.
Google’s Mobile-Friendly Test tool scans your website and evaluates whether it will look good on a mobile screen. It also provides a report on the overall usability of your website. For example, if a page only partially loads on a mobile device, it will tell you which elements, including images, are problematic and need to be fixed.
7. Use Copyright-Free and Good Quality Images
All images uploaded to your site should be copyright-free to avoid the risk of lawsuits, which will not only damage your online reputation but also your site’s ranking in search results. Shutterstock, Unsplash, and Getty Images are some of the most prominent stock image providers. These websites contain thousands of free licensed images for a variety of purposes.
Alternatively, head to Google Images’ Advanced Search section and find images based on different Usage Rights. As part of your image optimization workflow, consider creating original and unique images for your site.
Especially if you run an eCommerce store, high-quality product images generate higher engagement and help drive sales.
5 Best Image Optimization Tools
Manually optimizing a large number of images from your media gallery can be a time-consuming process. Fortunately, there are many online tools available to optimize your images and improve site speed.
Let’s take a look at five options worth considering:
1. Imagerecyle
This image optimization tool supports a variety of image formats, including JPEG, PNG, GIF, and even PDF files.
Based on the size and dimensions of the images, ImageRecycle can determine which images on your website need adjustment. All you have to do is enter your website address, and the tool will send you a free report to your email.
2. Kraken.io
This image optimizer provides multiple ways to optimize images, such as reducing image file sizes and using smart lossy compression techniques.
However, Kraken’s free web interface has a 1MB image size limit. For larger limits and more advanced features, you can opt for one of Kraken’s premium plans. Alternatively, WordPress users can take advantage of the Kraken.io Image Optimizer plugin.
3. iLoveIMG
This free online image optimizer offers a wealth of image editing tools. You can convert file formats, adjust image file sizes, add watermarks, and more. iLoveIMG lets you optimize images from your computer, Google Drive, or Dropbox.
4. Optimizilla
This image optimizer shrinks images to the minimum possible size without compromising their quality. It supports JPEG, JPG, GIF, and PNG formats and allows you to simultaneously resize up to 20 files. Additionally, you have the option to control the level of compression applied to the images.
5. Smush
With its Bulk Smush feature, this WordPress image compression plugin can optimize up to 50 images in a single click. Smush lets you set the maximum image resolution for file formats like PNG, JPEG, and GIF and comes with a lazy loading feature to improve site performance.
Opting for the premium version of this WordPress plugin lets you convert images to WebP and access additional image optimization tools.
Best Practices for Image Optimization
Optimizing images for your website can dramatically improve user experience, reduce load times, and make your site more efficient. Here are some best practices to help you optimize images effectively:
- Choose the right format: Choosing the right image format is critical to optimizing images. JPEG is ideal for photographic images, while PNG and GIF are great for illustrations, logos, and icons. WebP is a modern format that offers excellent compression without sacrificing quality.
- Compress images: Compressing images reduces their file size without negatively impacting perceived quality. Use lossy compression for photos and lossless compression for graphics and text-heavy images.
- Resize images: Serve images at the right dimensions for your website layout. Resize your images to fit the container or column they’re displayed in to avoid excessive scaling and reduce file size.
- Use CSS sprites for icons: Combine thumbnail images and icons into a single image (a sprite), then use CSS to display the appropriate sprite segments. This technique reduces the number of server requests for images, speeding up page load times.
- Implement lazy loading: Lazy loading is a technique that delays the loading of images until they are nearly in the user’s viewport. This reduces the initial load time of a web page and ensures that users only download the images they interact with.
- Implement responsive images: Use the <picture> element or srcset attribute to display different image resolutions based on the user’s device and screen size. This ensures that the appropriate image size is served to the user, reducing bandwidth usage and improving load times.
- Optimize image delivery: Use a content delivery network (CDN) to cache and serve your images from edge servers close to your users. This results in faster load times and reduced server load.
- Review and update regularly: Review your website for outdated or oversized images and update them as needed. This ensures that your site remains optimized and efficient over time.
How to optimize an image for mobile device?
As mobile traffic continues to grow, optimizing images for a smooth experience across devices is essential. Here are some tips for optimizing images for mobile devices:
- Adaptive images: Serve adaptive images using techniques like the <picture> element or srcset attribute. This allows you to provide different image resolutions and file formats to suit different devices and screen sizes, reducing the amount of data downloaded and improving performance.
- Compressed formats: Use modern compressed image formats like WebP, which deliver excellent quality with smaller file sizes. Smaller images load faster on mobile devices, reducing latency and bandwidth usage.
- Responsive design: Implement responsive design to ensure that your website looks and functions well on all devices, regardless of screen size. Responsive layouts adapt to the user’s device, resizing and repositioning elements for optimal usability.
- Create separate versions: In some cases, it can be helpful to create separate versions of images that are explicitly designed for mobile devices. These mobile-optimized images can be smaller, reducing file size and improving performance on smaller screens.
- Avoid over-scaling: Avoid using large images that require extreme scaling on mobile devices. Serve images that closely match the target display dimensions to reduce scaling and ensure a crisp, clean appearance.
- Optimize background images: Use CSS media queries to serve background images tailored to specific screen sizes and devices. This ensures that the appropriate image is loaded for each device, reducing unnecessary downloads and improving performance.
Conclusion
Having a website means you need to be ready to adapt to changes in search engine algorithms, technological advancements, and evolving user expectations. This also applies to all the images you post on your website.
Since modern internet users are quickly drawn to visual content, it’s easy to see why image optimization is one of the key variables that contribute to the overall performance of your website.
Reduced user satisfaction, slower page load times, higher bounce rates, and fewer leads are all possible consequences of not optimizing your website images. High-quality image optimization not only helps build your brand’s authority online but also improves its position in search engine rankings.
With an image optimization plugin or online tool, you can easily optimize your images in just a few clicks. You can significantly reduce the size of large image files without compromising their quality.
Remember that optimizing images is just one component of providing a great user experience. You can further improve the overall quality of your website through elements such as security, trust, and accessibility.
We hope the tips provided in this guide will help you take advantage of the benefits of optimization for both your website’s page load speed and its image SEO performance. Good luck...!!!
