How to optimize images for search engines

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Clicks, views, optimization, compression, and rank – the language for online content production and marketing is getting increasingly sophisticated by the day.

For companies launching new websites, Search Engine Optimization (SEO) is a vital step in ensuring that their customers can find them on the web. SEO analysis helps create the right type of keywords and phrases that will attract the target audience to the digital storefront, where sales can take place. Bloggers and entrepreneurs tend to hurry through when they are uploading pictures for their websites, often ignoring key aspects of optimization. There is more to image optimization than just simple compression.

Pick what fits

The right image will strengthen content, while an image without any contextual sense will make a website appear amateurish and unprofessional. Especially when links to websites and blog are being shared on social media, the image thumbnail may be the solitary deciding factor in the user clicking on through.

The first choice should always be original, authentic photographs made just for the business or the website.

If stock photos are to be used, there should be a deliberate effort to avoid using overly common pictures.

  • Unsplash provides a large collection of quality, royalty-free stock photos for private and commercial use.
  • Flickr also has an immense database of images, however, not all photos are licensed for commercial use. The user can toggle through the search settings to filter out the required photos which are tagged with the required permissions, such as to modify or use the image on your website.

See here 5 great tips on picking the right photos for your website.

Be finicky about format

Following the selection of the image for blog or website page, the next step is to decide upon the right file format. There are four main types of image formats that are applicable in this scenario:

  • JPEG – This is the most popularly used image format, despite it not providing any support for transparent backgrounds. Since JPEGs use lossy data compression, the image quality can suffer if the settings are not primed. The major advantage of working with the JPEG format is that it is widely supported and the file sizes are usually smaller than the other formats. Nothing loses an online visitor like a slowly loading website; faster-loading images keeps the bounce rate low on websites. JPEG images are great for photographs.
  • PNG – This format supports transparency, has a wider color range and comes with automatic gamma correction. All these features make PNG a preferred alternative to both JPEG and GIF file formats. While the file size can be larger than JPEG, it does store a short text description to aid search engines in categorizing images on websites.
  • GIF – As it only supports 256 colors, GIF is a bitmap image format that should only be used for simple animations and artwork. GIF will not be able to support photorealistic images or traditional photographs. GIF works well for smaller page elements and logos.
  • SVG – the vector format for the web. Great for logotypes and simpler illustrations.

Tweak for the web

Setting up images for maximum searchability includes reducing file sizes as much as is possible, without losing out on image quality.

  • Modern tools such as Weld will optimize high-resolution images automatically, removing the problem entirely.
  • You can also use platforms such as imgix to optimize your entire image bank.
  • To compress images manually, use online compression tools like Compress JPEG or TinyPNG.

Name image files smartly

Every aspect of an image uploaded to the web makes an impact on SEO results, even the file name. If the image is being downloaded from an external hard drive disk or a camera, it is recommended to give it a newer, more descriptive name. Search engines can easily latch onto images named something like: IMG_Atlanta_MallFestival_2014_06.

Take care of alt text

Alternative text (alt tags) can be provided for search engine and accessibility reasons. Alt text is meant to highlight the identity of the image, especially in situations when the image has not loaded correctly. Alt text is also utilized by screen reading tools to assist visually impaired people to navigate the web. A simple alt tag provides enough information to alert Google and other search engines to what the picture really is.


  • Each image should have an alt tag that describes the image.

Does Google rank images differently?

A common concern for content developers is how search engines like Google rank an image with text inside (as part of the image) that has an “alt” tag versus an image without text but with HTML text on top.

SEO experts do recommend using “pure” images with separate HTML text, rather than using an image with text inside (as part of the image). But what is more significant for SEO ranking is the caption, the inclusion of text near to the image, the alt tag, and addition of extra HTML text.

Michael Wahlgren, SEO expert and founder of SEO firm Pineberry, says:

“Everything else equal, it’s better if an image has HTML text instead of the text being in the image itself. However, my assessment is that the SEO effect of this is minimal, barely measurable. Other things are more important for how images rank on Google – the alt tag being the most important. Accessibility is a much bigger reason than SEO to use HTML text.”

According to Poynter Research, images with captions not only add more context to an image but result in up to 16% more readership.

Use Google structured data

You can add special markup code to your web pages so Google can display extra information about the images in Google Image Search.

Michael Wahlgren from Pineberry comments:

“Google is putting more emphasis on image search these days. Product markup tags will definitely increase the commercial value of images.”

Set up image sitemaps

Google suggests the use of image sitemaps to provide their search engine with additional information about your website. Sitemaps provide information about all images on the site, even those being loaded by a JavaScript code, such as slider galleries and product images. Add image information to your pre-existing sitemap and you are good to go.

Ditch 3rd-party image hosting

Save your business from potential embarrassment by opting out from uploading images on image hosting services like Postimage or Imgur. While these are solid short-term solutions for saving some space, there is a chance your images will get deleted when the hosting service has high amounts of traffic.

Boost your images with social media

Utilize social media websites like Pinterest or Tumblr to draw customers to your website. The easiest way to this is to link your website through social media sharing buttons; Pinterest provides a simple red button that asks readers to “Pin It” to each linked photograph and blog.

Visual search technology has improved remarkably in the last few years, however search engines still primarily depend on alt text and other image-related information from the content creator. Optimized images result in better user experiences, pages that load faster and increased ranking opportunities, via both image search and traditional search results.

Further reading:

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