SEO Training Tools

Optimizing Images for SEO

Google's vision for the future of search includes visual search. The utilization of AI by Google to analyze images and serve them integrated in the search engine results page means publishers need to prioritize their image optimization efforts. Images are not just important for attracting and keeping users, they are highly effective for boosting SEO performance. Use the tips below for effectively optimizing your images for Google.

1950’s Hubley steamroller toy
When possible use original photography for your images, use your keyword in the filename, and write alt text that describes the image. A good caption for this image would be, In 1950 the Hubley Toy Company made a line of tin toys representing agriculture and construction vehicles, these sold until the mid 1960’s.

Upload Unique and High-Quality Images

Uploading high-quality and relevant images can enhance the user experience. Over time, it can improve website traffic and create awareness for your brand. When selecting images, use images that are original if possible, relevant to the topic of the page, and optimized technically. Select captivating images and consider uploading more for every post.

Image Optimization Starts with the File Format

JPEG (or JPG), GIF and PNG are the most commonly used image file types. We would recommend you use JPEG, especially when uploading colorful images. For simple images, a PNG would suffice.

JPG or JPEG (they mean the same thing)

JPEG is short for Joint Photographic Experts Group and is best for photography and images with vibrant colors and contrast shading. JPEGs are also great for decreasing overall file size without significant reduction in overall quality, more on this in a minute.


PNG is short for Portable Network Graphics and was designed specifically for web use instead of print, because of this there is no support for non-RGB color spaces such as CMYK. PNG’s also offer the ability to have transparent backgrounds which is great for logos.


GIF is short for Graphics Interchange Format and is limited in color palette, tends to have block-like edges, but can be animated by combining several images into a single file. GIF’s are ideal for text and/or large blocks of color, but only use if compression value is better than the JPEG or PNG format.


WebP is an alternative file format developed by Google to decrease image file size while maintaining quality compared to JPEG and PNG. Unfortunately WebP is not widely supported, Safari does not currently support WebP images, but as adoption increases this will become a preferred format in my opinion.


SVG stands for Scalable Vector Graphics and is used to scale vector images at any size without loss of quality and can be easily localized by updating the text within them, without the need of a graphical editor to do so. Images are manipulated via XML, which means they can be searched, indexed, scripted, and compressed. Use of SVG format for vector based logos and icons is the most common usage, but is not limited to only these items.

sears-roebuck-sign.jpeg - jpeg version of Sears Roebuck Sign sears-roebuck-sign.png - png version of Sears Roebuck Sign
Above is a comparison of a jpeg and png of the same image before compression, the file sizes are 113KB and 464KB respectively.

File Size or Compression

As Google moves to put more emphasis on performance and user experience things that are gaining importance for optimization include the file size of your images. Logically the smaller the file size the less time it takes for the image to be downloaded from the server and rendered on the page. This increase in page performance is a key element of the Web Core Vitals formula rolling out in May 2021.

So how do you ensure your images are optimized to reduce the overall file size? There are several tools available to do this, some take more technical knowledge than others.

sears-roebuck-sign-compressed.jpeg - jpeg compressed version of Sears Roebuck Sign sears-roebuck-sign-compressed.png - png compressed version of Sears Roebuck Sign
Above is a comparison of a jpeg and png of the same image after compression. The file sizes are 55KB and 145KB respectively.

Image Format & Compression Tools

Below is a list of tools that are widely utilized to compress image files for SEO.

Image Size

Keep in mind that file size and image size are two different things. Image size is the dimensions while file size is the space needed for storing the image in the server.

Optimize Your Image File Names

When it comes to ranking in the SERPs, it's imperative to use keyword-rich image file names. An image with the filename "IMG_87569" does not provide any indication of what the image is about, this includes both humans and spiders. A generic image filename is not going to help your SEO efforts. Change the file name to something more relevant to the image and use your targeted keywords if possible. This is also a good time to use variations or related keywords and phrases to your target keyword. For example, if your target keyword is “motorcycle-backpacks”, use “waterproof-motorcycle-backpacks” as your file name, and use hyphens and not underscores. When naming product images this is a good opportunity to use the style or product number for the product.

  • Communicate what the image is about without seeing it. If your article is about motorcycles and you have images of different motorcycles, use the name of the motorcycle in the filename
  • Add example of image of motorcycle with example file name
A tanker ship sailing under the Astoria Bridge
Above is an image of the Astoria Bridge in Astoria Oregon. The filename for the image is astoria-bridge.jpeg.

Image Text SEO

Write Keyword Focused Alt Text

Alternative texts, alt text, or alt tags are all the same and are essential for search engines to accurately index the image on your website for image search results. While users know what the photos are about, you'll need to go the extra mile for SEO purposes. If you want to get better rankings, use target keywords for Alt Tags.

Optimize the Image Title

When the title is completely irrelevant or doesn't speak for the image, change it. As much as possible, include the keywords you are targeting in the title. While they do not directly affect SEO, they do provide context to your alternative texts. They also help with user engagement and the latter can boost SEO performance.

Write Good Captions

Write compelling captions and watch your bounce rates drop. A good caption can add depth and even intrigue users. Do you want to engage users and create a better experience for them? Craft enticing yet informative caption for the readers. They may not directly boost SEO but it's an effective way to keep readers wanting for more. To maximize use, include target keywords.

  • Should be descriptive enough that, if scanned, provides the gist of the article. Not necessary for all images

Here’s what Google says:

Google extracts information about the subject matter of the image from the content of the page, including captions and image titles. Wherever possible, make sure images are placed near relevant text and on pages that are relevant to the image subject matter.

What Else?

Image Sitemap

Through Google Image Sitemaps, Google receives metadata regarding the images contained on a website. This can help Google discover images it may not find through crawling, such as those accessed via JavaScript forms.

To provide Google with information regarding images on the website, the site owner must add relevant details to the standard Sitemap. This includes the type of image, subject matter, caption, title, geographic location, and license. The process enables site owners to identify which images on each page are most important.

Add image structured data

Adding structured data to your pages can help search engines display your images as rich results. While Google says structured data doesn’t help you rank better, it does help to achieve a more fleshed-out listing in Image Search. There’s more, though. For instance, if you have recipes on your site and you add structured data to your images Google can also add a badge to your images showing that this image belongs to a recipe. Google Images supports structured data for the following types:

  • Product
  • Video
  • Recipe

Google has a number of guidelines you need to follow if you want your images to appear rich in image search. For one, when specifying an image as a structured data property, make sure that the image actually belongs to the instance of that type. In addition, your image should have the image attribute and your images should be crawlable and indexable. You can find them all on Google's Structured Data General Guidelines.

Optimize for Image SEO Today

While optimizing your content contributes to getting better rankings in Google, it's not the only strategy that you can utilize for your business. To maximize your marketing efforts, start optimizing all of your images to rank as part of Google images search results. Use the helpful tips above — they are fairly easy to implement. Begin with selecting only relevant and high-quality photos for every post that you publish. Then work on the size, title, file name and type, caption and alt tag. Remember: As a business owner, your ultimate goal is to boost brand awareness, build more traffic, get better leads and skyrocket sales. Image SEO may not be the all-important factor for the SERPs but it's a surefire way to improve on-page SEO. Do this consistently and you will undoubtedly get better rankings and grow your business.

Keep these things in mind when adding an image to your content:

  • Use a relevant image that matches your text
  • Pick a keyword focused file name for your image
  • Make sure image dimensions match the image size as displayed
  • Use srcset if possible
  • Reduce file size and compress for optimal loading
  • Add a keyword/phrase focused caption, if appropriate, for easier scanning of the page
  • Use image alt text, make it descriptive of the image and utilize keywords when natural
  • Add structured data taxonomies to your images
  • Create an image specific sitemap and incorporate image attributes in other sitemaps
  • Provide context to your images, place them near the relevant content, use filename, alt text, titles, and captions to provide as much context as possible