There are two important reasons why website owners, bloggers, and online content creators should care about image accessibility. The first reason has to do with digital accessibility compliance (and doing the right thing). The second reason has to do with your business: Image accessibility secondarily benefits your online content by reaching a wider audience.
First, we’ll define what we’re talking about when we refer to images. Then we’ll explain how image accessibility benefits readers with disabilities and your business (win-win!). Last, we’ll cover best practices for making images accessible and writing good alt text for images.
6 Common Image Types
When we talk about image accessibility, we’re talking about a specific digital file type—pictures, photos, drawings, illustrations, graphs, and graphics. If you search for a complete list of image file types, you’ll likely land on a Wikipedia page that contains dozens and dozens of image file types. The majority of images are in these six file types:
- .jpeg
- .gif
- .png
- .tiff
- .bmp
Less common, these file formats are also used online for publishing images:
- Vector files with these extensions: .ai, .eps, and .svg
- Smartphone files with these extensions: .heif and .heic
- Google files with this extension: .webp
(If you would like to learn more about the history of these image file types and why there are so many, we recommend exploring Adobe Creative Cloud’s Image Files section. Their knowledge base offers a deep history of image files, including when they were invented, who started them, and how the formats are best used.)
Even with the advancement of artificial intelligence, technology isn’t quite there yet with being able to read and interpret images. That’s why you, as a content creator, need to include information in the image files, to help the assistive devices read and communicate the content of your images. We get into that next.
Image Accessibility: Good for Business, Great for Readers with Disabilities
There are two important reasons why accessible pictures, images, and photos matter in digital publishing: WCAG compliance and digital inclusion (benefitting readers with disabilities) and SEO benefits (benefitting your business’s searchability online).
Image accessibility, digital inclusion, and WCAG compliance
As an agency that offers consulting, auditing, and remediation services in accessibility compliance, WeCo is always on the forefront of the latest updates to Web Content Accessibility Guidelines (WCAG). WCAG is the official web standard for accessibility, and it’s the basis on which we build our audits, testing services, and client training. It is also the most trusted path to creating digital inclusion for everyone to encounters your website.
In short, the World Wide Web Consortium (W3C) created and maintains the WCAG, which is a set of standards that help website owners make sure their digital properties are accessible to people with disabilities. The standards apply to websites, e-commerce sites, mobile apps, downloadable software apps, and web-based platforms.
If your site isn’t compliant with WCAG or is inaccessible to people with disabilities, you could face legal issues. Lawsuits are on the rise being driven in part by “quick fix” accessibility remedies, like overlays, that rely solely on automation to meet the needs of people with disabilities. The Americans with Disabilities Act (ADA) web rules are also adding additional requirements for businesses in the US to be aligned with WCAG standards.
WeCo’s team of accessibility testers and auditors is well-trained and available if you have questions or want a consultation. Contact us to learn more.
Image accessibility and search engine optimization
Image optimization for accessibility has a secondary benefit for SEO because search engines (Google being the largest) use the data that you attach to published images as information for learning what your digital content is about. It helps search engine’s algorithms evaluate your content. A website with optimized images has a better chance of showing up in search results.
The data that you use for image optimization is called “alt text,” or alternative text. Screen readers read the alt text aloud to people who have visual impairments. Browsers (Chrome, Firefox, etc.) display alt text when poor or slow connections prevent images from properly loading.
Because search engines read the alt text (also referred to as alt attributes and alt descriptions), the data helps your content show up in search engine results pages (also known as SERP). One study found that by implementing alt text, blog traffic increased by 779% within a year, and organic traffic increased by 160,000 views (Hubspot).
What is alt text, where do you find it, and how do you write good alt text?
How to Write Alt Text for Images
Most CMS (content management systems) include a field to add alt text when you upload images.
In this WordPress example, which is one of the most-used CMS, you open the alternative text field with a single-click on an uploaded image. Most other CMS have a similar tool, where you upload the image, select it in the media library, and add the alternative text.
The real question is, what do you write for alternative text? How detailed do the descriptions need to be? We like the advice that SuperCoolDesign offers: Write alt text as if you were briefly describing an image to someone over the phone.
Here are some do’s and don’ts for creating alt text:
- Don’t include, “This is a photo of…” or “This is a screenshot of…” or even, “Image of…” The user knows it’s an image.
- Do rename your photos to match or align with the alt text.
- Don’t worry about adding alt text to decorative images or illustrations. This includes headers and images that are added for artistic touches. (Mark these as “decorative” in your alt text box.)
- Do keep your alt text descriptions short and to the point for most images. (Some images with more complex information, like a graph, may require a long description alt text.).
- Do include context that’s relevant to the story or page copy (see examples in the next section).
Examples of different types of alt text
Alt text with no context: Six mailboxes
Alt text on a page about living in the rainforest: Six unique mailboxes nailed to a wooden perch in a tropical setting.
Alt text on a page about finding art in unexpected places: A photographer captures six colorful, unusually shaped mailboxes nailed to a wooden perch in a tropical setting.
How long should alt text be?
Screen readers will cut off alt text around 125 characters, although there are exceptions, such as when an image is the main focus of the content (SuperCoolDesign). If you’re struggling to shorten the alt text, remember that you can use the surrounding page copy to set up the content of the image.
Why can’t you just use captions instead of alt text?
Captions are visible text that accompanies images. Alt text is not visible (unless an image can’t load, such as when someone has poor internet connection). While you only need one or the other, we suggest that you use both when the information would be helpful to everyone. For example, including a caption would be helpful for photos of people winning an award if you want to share the names of everyone featured. A caption would also benefit everyone if you’re showing a complicated graph that requires an explanation. Otherwise, do one or the other: include a caption with your image or include the alt text. SEO experts recommend alt text because Google and other search engines specifically look for that when they crawl sites looking for images.
Tools for alt text optimization and accessibility
As you are learning how to write good alternative image text, this alt decision tree from W3.org can help you decide whether you require an image description for accessibility.
Ahrefs offers a free alt text generator that uses AI technology. We tested it with the stock image of the mailboxes, and it did a decent job: Mailboxes in front of a bush: A row of mailboxes stands in front of a lush green bush, creating a picturesque scene.
Alttext.ai is another tool that generates alt text. It’s free to try, and then it runs on a subscription basis, although the price points are low. It’s $5/month for 100 credits, which equates to 100 alt text descriptions. We tried it for free with our mailbox photos, and this is what it delivered: A row of variously styled mailboxes on a wooden fence amidst green foliage.
It’s important to note that AI-generated alt text is not reliably accurate. Accessibility experts, including our team, agree that human review of AI-generated alt text is essential to ensure that thee text is meaningful to the user. WeCo provides AI Alt Text Review services, delivered by professionals living with disabilities. Contact us to learn more about our alternative text services.
Are Your Images Accessible?
If you’re concerned that your website, software program or application has images that aren’t accessible, the best place to start is with a WeCo Alt Text Review. To learn more, contact us.
Our team of accessibility experts will evaluate, correct, or add alt text to the images on your website. We can also train your team on best practices for images, so going forward, your content is accessible to all.
Schedule a call, and let’s talk about your images.
Learn more about image accessibility
- Interested in learning more about crafting alternative text? We offer courses about image accessibility, as well as all aspects of digital accessibility, on our self-paced, online training platform WeCoLearning.
- Read about how artificial intelligence (AI) impacts image accessibility in our blog Is AI the silver bullet of accessibility?.