15+ Important Image Optimization Tips for Better SEO

Images take up a lot of space on your website so it is best to optimise them for better user experience and functionality. You should optimise your images for better rankings and traffic.

More and more businesses are adding visual content.

Here are a few image optimization tips to help Google read and rank your images:

1. Choosing the right file type for the different types of visual content can bring a huge improvement. JPEG format for pictures, PNG for logos or pictures with solid colour or when you need to use transparency and GIF format for animation.
   Image file formats WebP format can produce high-quality results with small file sizes. It is supported by Chrome and Firefox. To optimise your images and website you can hire Ethical SEO services.
   
2. Images tend to be too large and too many of them can bring the page load speed down. Faster website means a better user experience. You can reduce the quality of the image to improve your website speed. Size of the image is given by the number of pixels so you can reduce the quality of the images by 15%-20%. There are PNG 8 bit and PNG 24 bit, you can use PNG 8 bit to keep your picture light sized. To reduce the quality while retaining quality of images you can use software like GIFsicle, JPEGtran, JPEG Mini, OptiPNG and ImageOptim.
   
   
3. Resolution is the number of pixels in an image and one of the ways to optimise is to save images at a smaller resolution. Compressed images are smaller in size. Tools like Google PageSpeed Insights can show the images that should be compressed and the space it will save once compressed. Use free tools like Pixlr Online Photo Editor to save images at smaller resolutions and editing needs.
   
   
4. Resize images to scale rather than let CSS and HTML resize them. Though this method can be used with websites that do not have a responsive web design. Other recommendations are crop white spaces from images and provide padding, do not use text within images, reduce bit-depth to smaller colour palette, use raster images only when necessary and minify your images.
   
   
5. Use plugins to automatically compress your images if you're using WordPress. Choose the plugins that work best for you. Some of the plugins are WB Smush, CW Image Optimizer, Insanity, Hammy, SEO Friendly images that will compress your images automatically.
   
   Image compression
   
   Images contribute to the overall page size, large images can slow down your website. Therefore you need to compress your images before uploading them to your website. You can use tools like Photoshop, TingPNG or WP Smush plugin for WordPress. 
   
   You can use an image CDN that detects the device and optimises the images before delivery.
   
   
6. The more original pictures you use the better the experience for the user and better chances of being ranked for relevant searches. Use original and high-quality images for better SEO. For large images you can consider Google Discover as they are likely to be featured in it.
   
   
7. Before you use a photo make sure you have the licence to use it otherwise you are risking a lawsuit. If you violate any copyright laws then you can be issued a notice under the Digital Millennium Copyright Act (DMCA). You can use Google Images to filter images based on those available for reuse.
   
   
8. Image file names tell search engine crawlers the subject matter of the image. Change the default filename to make the search engine understand your image. This will help to improve SEO value.
   
   Image naming and Alt-tags
   
   Change the filename from default and create descriptive and keyword-rich file names. The image file name tells the search engine the subject matter of the image. If you are translating or localising your images then you should change the file name accordingly.
   
   
9. ALT tags are text alternatives to images and you should use them to describe the contents of an image. If the image does not load then the user will get the ALT text. This can also help you achieve better ranking if you associate keywords with images. ALT text is also required for individuals who cannot view images themselves.
   
   Image naming and Alt-tags
   
   Alt-text is used for an image so that there is descriptive text available in case the image cannot be displayed. It helps to enhance a website’s accessibility. For visually impaired users Alt-text tells them exactly what is in the photo. You should use SEO-friendly Alt-tags which include keywords.
   
   Alt-text in images is useful as an anchor text if you are using an image as a link.
   
   
10. File path and file name is used to rank images by Google. If you have an ecommerce brand then you should create subfolders for products images rather than placing them in one folder. You can create folders like ‘/shorts/’ and ‘/denims/’ rather than one generic/ media/ folder.
    
    Image file structure and organisation
    
    Instead of using one generic folder you can structure your subfolder with category-related topics and place the image.
    
    
11. Devices that capture the images, automatically create metadata like exposure time, camera type, date taken and more. This information may be useful for photography websites but for others it is irrelevant. You should delete this unnecessary image data. This will help to optimise your images and it will also be easier for search engines to understand the visual content. Use Google Chrome extension - EXIF viewer, Photoshop or Adobe Lightroom to get rid of unnecessary data.
    
    
12. Scalable Vector Graphics (SVG) can be used for logos, icons, text and simple images. The entire content of SVG is just text and it is recommended to use them to create better websites. There are many advantages of using vector images like scalable in browser and editing tools, zoom in or zoom out does not affect their quality, you do not lose quality SEO, they are indexed the same way as JPEG and PNG files and they are smaller in size.
    
    
13. Google uses page titles and descriptions as a part of its image search algorithm. You should add metadata, header tags, copy on the page and structured data as they can affect how Google ranks your images.
    
    
14. While using AMP or PWAs you need to define your image dimensions. You should include the height and the width attributes for every image and video element. This tells the browser how much space to allocate for the resources and prevents the Cumulative Layout Shift (CLS) issue that lowers the CLS score. Defining the height and width leads to a better user experience.
    
    Image size dimensions
    
    You should define the dimensions of your images as it offers a better user experience. If your images are large then it can slow down your website. You can resize your images to maximum display dimensions.
    
    You can use tools like Photoshop to resize images manually. For WordPress, you can use Resize Image After Upload and choose the size you want.
    
    
15.  Optimise your images for mobile as it can give you more ranking power and better user engagement. For this, you should create responsive images as they can adjust to the size of the device used.

Mobile optimisation

You should optimise your images for mobile-first indexing. You should use a responsive image that will scale with the size of the website.

Image captions and surrounding text

The image caption is the text used with the image on a page. It appears below each image when used in an article.

The surrounding text should provide a stronger and more important signal about the image. 

Lazy loading and responsive images

Lazy loading allows you to defer slow-loading elements until the page is rendered. This makes sure that the user gets to your website before loading the bigger and non-critical elements of your page. You can use tools like WebFx to implement lazy loading.

Responsive images mean you can change the layout of the image based on the device's characteristics. For this, you need to use the ‘srcset’ attribute, which allows you to serve a different image per screen width.  

Image sitemaps

You can create an XML image sitemap to give Google more information about the images on your pages. It helps to indicate images you want  Google to crawl and index. Image sitemaps can contain URLs from other domains and therefore you can use an image CDN.

Monitoring and optimisation

You can use Site Audit tools to find any issues with images that need to be fixed.

Before you upload your images you should optimise them by making sure the images and the ALt-text are relevant to the page, use the right file format, reduce file size and more.

Conclusion

Optimising your images helps to improve your website performance and traffic.