How to Optimize Images for SEO and Social Media 

 March 27, 2021

To search engines and human readers alike, images are as important as words.

That’s why it’s equally important to optimize images you add to your blog, social media, and other content. Like words, images are critical for both search engine optimization (SEO) and social media optimization (SMO).

According to plenty of research, images make content much more shareable. Some say the more, the better.

But the number of images is only one factor. More important than quantity is quality: how to optimize the images you use. If using 10 images slows your page loading to a crawl, that in fact hurts sharing because no one will even see the page to share it.

This post looks at simple but crucial ways to optimize images for your blog so that they’re both seen and shared by search engines and readers. It’s important to consider the image itself, but also two bits of text attached to the image.

This is the third of three posts covering the basics of optimizing content for both search engines and searching eyes. Here’s the other two:

Why Optimizing Images is Vital

Correctly sizing your images helps with one of the top most important factors in search engine ranking: page load times.

It won’t matter what’s in your image if people don’t stick around waiting for it to appear. They’ll click on your competitor’s link, which makes that content more useful in the eyes of search engines. Yours won’t be seen at all. So your content’s ranking drops.

Image Size

The biggest factor here that you control is image size. By “size” I mean two related things:

  1. Image size in pixels x pixels (“resolution”)
  2. File size in kilo- or megabytes (kb or Mb)

The larger the first, the larger the second (generally speaking).

Second, social media channels all have their own optimum resolutions for display on feeds and pages, and these change from time to time.

Some marketing companies helpfully maintain comprehensive cheat sheets you want to add to your bookmarks or favorites. The ones from Sprout Social, Hootsuite, and Buffer are especially worth keeping handy.

Image formats

Choosing the correct file format and quality can keep images files smaller. You’ll need to experiment a little to see what works best.

The most common and recommended formats are JPEG and PNG (Portable Network Graphic). The PNG format was developed for online compatibility, but JPEGs are typically smaller in size. Depending on the image, you can reduce JPEG image quality without visible loss of clarity, for even greater size savings.

Tools for optimizing images

Popular image apps like Canva include all the formatting tools you need to optimize your images for any blog, social media channel, or other use. It’s simple to use, and comes with a mobile app.

Adobe’s advanced suite of desktop and mobile apps includes Photoshop and Spark for creating optimized images in the office or on your phone or tablet.

Another optimizer is Blogstomp, a service created for photographers, that lets you optimize images and layouts.

Social sharing plugins like Social Warfare (affiliate link) let you select a sharing image that’s different from the featured or banner image of your blog post. Website themes may use post image sizes different from the social media cheat sheets. With the plugins, the social-optimized image is shared instead.

Words and Images

As important for SEO as the image itself is the text that’s part of the image. That means

  • the file name and
  • the alt tag, the line of text you may see briefly before an image loads, or after when you mouse over it.

You may also consider putting text on your images. That does not directly affect SEO, because search engines can’t read it. But human searchers can; that’s part of human SEO.

To search engines and readers, images are as important as words.Click To Tweet

On the image

Text on images helps your social media optimization (SMO) too. In a crowded, scrolling social media feed, text on an image makes it instantly clear what the content is about.

In the survival-of-the-fittest contest for clicks, that’s a clear advantage over images with no text, because people may not read the title or description below it.

File names and alt tags

Along with post titles and URL slugs, image file names and alt tags count among the first places search engines look for your content’s keyword.

Both need to contain your keyword verbatim.

For example, here are the file names and alt tags I used for the featured and two internal images on a post with the keyword content calendar.

File Names

  • get-started-create-content-calendar-blog-randy-lyman-writing-age-of-lies.jpg
  • airtable-content-calendar-blog-randy-lyman-writing-age-of-lies.png
  • coschedule-content-calendar-blog-randy-lyman-writing-age-of-lies.png

Alt Tags

  • How to Create the Perfect Blog Content Calendar | Randy Lyman – Writing for the Age of Lies
  • Airtable – How to Create a Blog Content Calendar | Randy Lyman – Writing for the Age of Lies
  • CoSchedule – How to Create a Blog Content Calendar | Randy Lyman – Writing for the Age of Lies

Search engines will find my keyword six times in these three images, plus three in my post title, meta description, and URL slug. So they’re clear right away that this post is about content calendars.

Two words of caution

  1. File names and alt tags need to accurately reflect what’s in the image, or the content of the blog post for the featured image. In my example, I used the app names to stand for screenshots of the apps (links are affiliates). That’s all it takes, but it’s important for describing your content to the algorithms.
  2. Don’t stuff keywords into these image texts, just like you don’t for blog posts. Stuffing is when you unnaturally pack the keyword into the content as many times as possible purely for the sake of more. Google got wise to this ages ago, and your content will suffer terribly in the rankings.

Image Content

Sharing Preview - Optimizing Images For Seo And Social Media | Randy Lyman - Writing For The Age Of LiesSocial sharing plugins like Social Warfare and SEO plugins like Yoast and Rank Math (pictured) let you preview how your blog post will appear on social media.

Finally, research shows that the content of your images matters too.

I know, free stock images are, well, free, so how can you refuse? But generic stock images are known to have less impact, to make blog posts less shareable.

They mark your content as generic, because people see these same images of happy deal makers shaking hands (etc.) everywhere. By contrast, showing real people in original images has a positive impact.

One solution that I use is to add titles and make other modifications. I love using free images from Unsplash, Pexels, Pixabay, Wikimedia Commons, and many other services. But I make them my own (like on this post).

In general, creating your own images — photos, screenshots, infographics — makes content much more shareable, not to mention — well, precisely because — it’s more interesting to read.


Optimizing images for your blog is just as important as optimizing your words.

Images that take too long to load can prevent your content from even being seen. On the other hand, sizing and labeling your images correctly can make your blog posts more likely to be both seen and shared.

And while SEO and SMO can indeed be large and complex topics, the part that you need to know for your daily content marketing can be easy if you know what you’re doing.

As I’ve said before, optimizing is work but not extra work. On the contrary, it’s essential.

Read my previous blog posts to get an overview of search and social optimization, and to learn how to optimize your written content along the same lines as you optimize images.

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