If you’re wondering about the importance of an image’s web accessibility, here’s a story from a business that will land the point:
Last year, our ecommerce site's bounce rate suddenly spiked to 70%. We were baffled until we received an email from a frustrated customer. They said they were visually impaired and wanted to buy our products, but their screen reader couldn’t read any of them. Eventually, they gave up trying to navigate our shop. We were devastated. How many other customers had we lost because of this issue?
This customer‘s experience isn’t unique. It highlights a widespread problem that many businesses unknowingly face.
Your website's images are often invisible to a significant portion of your audience — including screen reader users, people with slow internet connections, and those with visual impairments.
If your website’s images aren’t accessible to this portion of your audience, they’re missing out on crucial content, which can cost you engagement, conversions, and credibility.
While many believe that adding alt text to images is sufficient, true web accessibility for images is far more comprehensive. It's about creating an inclusive design that works for every visitor.
After reading this guide, I guarantee you’ll be able to create fully accessible images that engage all web visitors, boost conversions, and future-proof your website.
Table of Contents
- What Is Web Image Accessibility?
- What Makes an Image Web Accessible?
- Key Factors in Image Accessibility
- How to Make Your Images Web Accessible
- Accessible Images on the Web
What Is Web Image Accessibility?
Web image accessibility is about making sure that everyone — especially people with visual impairments or disabilities — can understand and interact with images on your website.
Image accessibility is an integral part of creating an inclusive and engaging online experience for all your website visitors.
.png)
Website Accessibility Checklist
This checklist will help you make the following more accessible on your website:
- Web Pages
- Navigation
- Video & Media
- And More!
Download Free
All fields are required.
What Makes an Image Web Accessible?
Before we examine what makes an image accessible on the web, we need to determine whether image accessibility improves engagement and usability for all users.
As it turns out — yes, it does. This study found that web accessibility, particularly for images, is crucial for users with various disabilities and can significantly impact their ability to interact with digital content.
Moreover, the study revealed that accessible design benefits all users, not just those with disabilities. You can think of web image accessibility is like building a ramp alongside stairs — it doesn't just help people in wheelchairs — it also benefits parents with strollers, delivery people with carts, and many others.
In the context of web images, accessibility ensures that all web visitors can understand and engage with your visual content.
Key Factors in Image Accessibility
When considering image accessibility, it's important to think beyond a single aspect and consider the various factors that contribute to an accessible image, as well as the context of the website.
Web users have different needs — some may be visually impaired, others may have cognitive disabilities, and some may rely on assistive technologies. So, a multifaceted approach to image accessibility performs best across different user groups.
The key factors in making images accessible include:
- Alternative text (alt text). Provides a textual image description for screen readers.
- Color contrast. Ensures that text and important visual elements are distinguishable.
- Image quality and resolution. Affects the ability of users with partial vision to perceive details.
- Captions and labels. Offers additional context and information about the image.
- Responsive design. Allows images to scale appropriately on different devices and screen sizes.
It's not enough to simply “add alt text and improve accessibility.” To develop an effective strategy for image accessibility, you need to:
- Understand your audience. Identify the specific needs and “accessibility baseline” of your target users.
- Align with content goals. Tailor your approach based on the type and complexity of your visual content.
- Implement multiple accessibility features. Address various aspects of accessibility to cater to diverse user needs.
- Test and iterate. Regularly assess the effectiveness of your accessibility measures and make improvements.
For example, a platform offering complex infographics, such as a data analytics tool, could implement the following:
- Detailed alt text to describe each chart or graph's data trends, key points, and visual elements, making the information accessible to screen reader users.
- High color contrast to ensure low-vision users can distinguish between different data sets, lines, or bars.
- Text alternatives or simplified versions of infographics to allow users to access essential information without visual complexity.
- Interactive elements to make the data more accessible by enabling users to explore the visualizations at their own pace.
This approach ensures that complex data is communicated effectively to all users, no matter their ability.
Meanwhile, an online store with a lot of product imagery, such as a fashion retailer, could add the following:
- Descriptive alt text for each product image to highlight important details like fabric, color, and fit, helping users who rely on screen readers understand the products.
- High-quality and well-lit images with good resolution which are key for users with partial vision who may need to zoom in to see details.
- Good color contrast between product images and the background to help users distinguish items more easily.
- Responsive images that adapt to different screen sizes to ensure a seamless experience across devices, maintaining accessibility on both mobile and desktop.
For a content-rich blog or news site:
- Alt text should provide descriptions for important visual content, such as photos or charts that accompany articles, while decorative images can have empty alt attributes to avoid unnecessary information for screen reader users.
- Captions and labels can provide context, helping users understand the relationship between the image and the article content.
- Responsive design ensures that images maintain clarity and readability across all devices, allowing for a consistent reading experience.
By implementing these strategies, the website makes content accessible while keeping the user experience smooth and inclusive.
How to Make Your Images Web Accessible
Making your images accessible doesn't have to be complicated. By following a step-by-step approach, you can ensure that all users, regardless of their abilities can perceive and understand your visual content. You can also use a website accessibility checklist to help you structure your approach.
Let's walk through the process of creating web-accessible images.
Implementing these steps will significantly improve the accessibility of your images and enhance the overall user experience of your website.
Step 1: Evaluate the necessity of the image.
Not all information needs to be conveyed through images. Overusing images leads to web accessibility issues, slower page load times, and confusion for web visitors.
To determine whether you should present information as an image or text, follow these questions and considerations.
Does the information require visual representation?
- Assess whether the information you want to convey will benefit from being in an image format.
What to consider:
- Impact and Clarity. Does the content lose significant meaning or impact if not presented visually?
- Unique Value of Visuals. Is the image providing information that can't be easily described in words?
For example, the pie chart below from our consumer trends report better illustrates the number of users who allow companies to track their personal data than a text description of the data would.
What purpose does the image serve?
- Understand the specific role of the image in your content. This will help you determine whether it's essential or merely decorative.
What to consider:
- Decorative or Functional? Is the image just decorative, or does it provide crucial information?
- Emotional Response. Is the image meant to evoke an emotional response?
For example, this bar chart showing effective channels for remote selling evokes an emotional response, which is hard to achieve with text alone.
Can text effectively convey the information?
- Evaluate if the text could serve the same purpose as the image. This is especially important for accessibility and faster load times.
What to consider:
- Clarity of Text. Would a detailed text description be just as clear and informative?
- Alternatives to Visuals. Could the information be presented in a simple table or list rather than a complex infographic?
For example, instead of using an image that says “Open 24/7,” simply write “Open 24/7” as text directly on your webpage.
By carefully assessing the necessity, purpose, and effectiveness of each image, you can strike a balance between visual appeal, information delivery, and accessibility, ensuring a more user-friendly and efficient experience for your audience.
Step 2: Ensure sufficient color contrast.
Color contrast refers to the difference in light between foreground (text or important elements) and background colors.
Sufficient contrast ensures that elements within an image are easily distinguishable from one another.
Since not all web users perceive colors and contrasts in the same way, color perception and contrast in design matters.
For example, individuals with visual impairments, color blindness, or those using specific devices may have difficulty distinguishing elements within images if the color contrast is inadequate.
Adequate color contrast is essential for:
- Improving readability and comprehension of image content.
- Ensuring that users with visual impairments can access information.
- Enhancing the overall user experience for all visitors.
- Complying with web accessibility guidelines (e.g., WCAG 2.1).
To ensure sufficient color contrast in your images:
- Use high-contrast color combinations for essential elements.
- Avoid relying solely on color to convey information.
- Test your images using contrast-checking tools.
- Consider creating alternative versions of images with enhanced contrast.
For example, to improve readability, instead of using light gray text on a white background, opt for dark gray or black text.
Website Accessibility Checklist
This checklist will help you make the following more accessible on your website:
- Web Pages
- Navigation
- Video & Media
- And More!
Download Free
All fields are required.
When creating infographics, use both color and patterns to differentiate between categories, benefiting users with color blindness.
For charts and graphs, ensure that data points and lines have sufficient contrast with the background and each other.
I recommend the following tools when checking the contrast ratio of your images:
- WebAIM Contrast Checker. An online tool that allows you to input color values and check their contrast ratio.
- Color Contrast Analyzer. A downloadable application for Windows and macOS that can analyze contrast ratios in your designs.
- HubSpot’s Brand Kit Generator. A free tool that you can use to create logos and color palettes.
I've been nurturing an idea for a unique pet product store. I decided to take HubSpot's Brand Kit Generator for a test drive to turn this vision into reality. Little did I know that this simple decision would breathe life into my concept in ways I hadn't imagined.
The process was a simple six steps: I entered my business name (Pawsome Picks), selected an icon, selected a font I liked, selected a primary color, chose my logo, and customized my brand kit.
When I saw the results, I was genuinely impressed. HubSpot‘s Brand Kit Generator didn’t just give me a logo; it provided a complete brand identity package.
It also offered typography recommendations that maintained brand consistency, and mock-ups showing how my online store could look, bringing the concept to life.
Hubspot’s Brand Kit Generator is an invaluable asset for businesses in the initial stages of development or those considering a brand refresh. It streamlines the branding process and provides professional-grade results.
Step 3: Minimize text within images.
Embedding text directly within images can unintentionally create significant accessibility barriers.
I've seen this happen on websites where critical information was trapped inside an image, leaving some users struggling — especially those who rely on screen readers or have visual impairments.
When text is embedded in an image, screen readers can't interpret it, translation tools are rendered useless, and zooming in often blurs the text, making it harder to read.
Search engines can't index the content either, which can harm your SEO efforts. I’ve seen the effects firsthand, particularly with marketing banners where embedded text didn’t scale well on mobile, leading to a frustrating user experience.
Consider an infographic packed with valuable data. But if all that data is locked inside the image, it’s as if it doesn’t exist for users relying on assistive technology.
To avoid these pitfalls and enhance both accessibility and SEO, here are some simple solutions.
- Use HTML text alongside images. Instead of embedding text within images, use actual HTML text. This ensures screen readers, search engines, and even mobile users, can access and interpret the content, providing better scalability and responsiveness.
- Use CSS to overlay text on images. Overlaying text using CSS keeps it separate from the image file. This method allows for dynamic styling, easy updates, and — most importantly — ensures that the text remains accessible, readable, and scalable across different devices.
Pro tip: Want to add CSS text overlays to images? I recommend reading our guide, Adding a Full-width Banner to Your Page, which provides step-by-step instructions. Pay attention to the background banner image section, which demonstrates how to overlay text on images using CSS to improve web image accessibility.
From my experience, making these minor adjustments leads to a better, more inclusive user experience for everyone while also keeping your SEO efforts intact.
Step 4: Implement proper ARIA roles.
Standard HTML attributes, like alt text, don’t always provide enough context for interactive or complex elements.
For instance, when a carousel includes clickable images, assistive technologies sometimes fail to convey their interactive nature, which can confuse users.
ARIA roles (Accessible Rich Internet Applications) provide the additional semantic meaning needed to enhance how assistive technologies interpret content. By clarifying the purpose of an image, they improve navigation for users with disabilities.
In a recent project, I used image icons as buttons. Initially, I didn't consider how screen readers would interpret these. It was only after adding the ARIA role of “button” that I realized the significant improvement in accessibility.
After adding the role, screen readers conveyed the correct information, improving the user experience. Similarly, in image galleries, ARIA roles helped clarify relationships between images, enhancing overall navigation.
Here’s how I implement ARIA roles:
- I start by deciding if the image is decorative, functional, or part of an interactive element.
- Using roles like image, button, or link helps me ensure that screen readers and other assistive technologies understand what each image is meant to do.
- I’ve found it helpful to include extra context, such as using the ARIA-label to describe the image’s function in more detail. This is especially useful in product galleries.
- I always try to use proper HTML tags like <img> and <button> first, relying on ARIA roles only when native semantics fall short.
By taking the time to implement ARIA roles, I’ve seen how much it improves the experience for users relying on assistive technologies, making websites more inclusive and easier to navigate.
Pro tip: When implementing ARIA roles, less is often more. Start with the most essential roles and attributes, then add more as needed based on user testing and feedback. Over-implementation of ARIA can sometimes lead to information overload for assistive technology users. For a deeper understanding of ARIA implementation, refer to this detailed guide on ARIA accessibility with examples and guidelines.
Step 5: Create responsive images.
Users access websites on various devices with different screen dimensions and resolutions.
What looks great on a desktop can break down on a mobile device, leading to slow load times, poor user experience, and even accessibility issues.
Without optimizing images for these varying screen sizes, we risk frustrating mobile users or those with slower internet speeds. I’ve often seen beautifully loading desktop sites become clunky and slow on mobile, causing users to bounce off the page due to poor image accessibility.
So, how can we ensure images are optimized for all devices while maintaining accessibility and performance?
Start by testing your existing images across different devices and browsers to ensure they display correctly. Use HubSpot's Website Grader tool to check your website's overall performance.
If your image size is inconsistent, consider using SVGs (Scalable Vector Graphics) for logos, icons, and simple illustrations.
SVGs maintain quality at any size, making them ideal for responsive design. This means your images can adapt to different devices, resolutions, and screen sizes, which can improve accessibility and user experience.
For non-SVG images, use CSS to automatically adjust their dimensions to fit the user’s screen size. This ensures that your images look good on all devices.
To control how images are displayed on different screen sizes, set breakpoints in your CSS to target specific device ranges, such as phones, tablets, and desktops.
By automatically adjusting based on the user's screen size and device capabilities, responsive images ensure the right image is displayed in any context, optimizing visual quality without overloading the site.
Website Accessibility Checklist
This checklist will help you make the following more accessible on your website:
- Web Pages
- Navigation
- Video & Media
- And More!
Download Free
All fields are required.
Step 6: Write effective alt text.
Most websites feature key visuals like charts or images that lack alt text or contain vague descriptions that don't add value.
When alt text is missing or poorly written, screen readers can‘t convey the content of important visuals to visually impaired users, and search engines can’t index the images.
To ensure images are accessible and properly indexed, writing effective alt text helps all users understand the content and allows search engines to index images for improved SEO.
I've found that writing compelling alt text is both an art and a science. It took me some practice to strike the right balance between being descriptive and concise.
Take a look at this image:
When writing alt text for such an image, here are my tips:
- Be specific and concise. Keep it under 125 characters. Instead of “Image of a chart,” write “biggest customer acquisition and retention challenges."
- The alt text describes why the image is there, not just what it shows. Screen readers already announce images, so avoid starting with “Image of.” Include relevant keywords naturally, without stuffing. Avoid jargon, as it makes it harder for visually impaired readers to understand your image.
- Use empty alt text (alt=“”) for decorative images so screen readers skip them.
- If an image contains text, include it in the alt text. Stick to the facts and let users interpret the image themselves.
For complex visuals like infographics or charts, alt text alone won’t suffice. A detailed description in surrounding text or a linked document ensures full accessibility.
By consistently using clear and thoughtful alt text, you can improve both user engagement and SEO. Websites that skip this critical step risk losing both audience and visibility.
Step 7: Optimize image file sizes.
I can‘t count the number of times I’ve visited a website on my phone only to give up because the images took forever to load.
It‘s often because images make up a big chunk of a web page’s total file size. Large images can slow things down, making the experience frustrating and less accessible for many users.
However, by reducing image file sizes, you can speed up loading times without sacrificing the site's appearance through image optimization. This involves reducing the amount of data needed to display images on a webpage — and you can do that by compressing images, choosing the right file formats, and adjusting their dimensions.
With all HubSpot-hosted content, the <img> tag also offers automatic image resizing and optimization features for any image with defined height and width attributes.
This ensures that images are appropriately scaled for different devices, leading to reduced file sizes and faster loading times without additional effort from you.
Optimizing images doesn't just make websites faster. It also uses less bandwidth, which is great for people with limited data or slower connections. Plus, faster sites tend to rank better in Google, and it can also help reduce server strain and save on storage space.
Accessible Images on the Web
How will your images look once you follow these steps? Here are some of my favorite (and web-accessible) images I have come across on the web that will inspire you when improving the accessibility of your images.
Slack's Accessibility Page
I notice Slack uses simple but effective visuals on its accessibility page, with clear alt text describing the interface and functionality of its software.
The descriptions of the images (like the one above) are not just labels like “Slack interface screenshot” but instead explain what the image represents, such as “channel navigation animation in Slack.”
This approach allows someone using a screen reader to get an informative picture of how Slack works without relying on the visuals alone.
HubSpot’s Product Pages
When I browse HubSpot’s product pages, I see images with detailed alt text that describe the specific actions being performed in their marketing tools. One example reads: “HubSpot simplified user interface showing a user creating an email message and adding a CTA button with the drag-and-drop editor.”
These descriptions give users who can’t see the images a clear idea of what’s happening and how the tool functions.
HubSpot also ensures that these images are optimized for speed and clarity, which is important for both accessibility and user experience.
Asana’s Task Management Software Page
I noticed that Asana’s use of screenshots and diagrams to explain workflows and tasks are often accompanied by accessible alt text that describes the process.
For instance, instead of saying “list of tasks diagram,” the alt text might read “automate work in Asana.” It is simple yet effective.
I find this especially helpful because it provides more than just a label: it explains the functionality being shown, offering users an inclusive and informative experience.
Create Images That Speak to All Users
As I delved into web image accessibility, I was surprised by how small changes can dramatically impact user experience.
I learned that well-crafted alt text is an art form, and I was amazed at how color contrast affects readability. As you work towards improving image accessibility, start by auditing your images' alt text and checking for color contrast in your designs using the tools I recommended.
I'd also recommend implementing responsive image techniques and optimizing file sizes for faster loading. These steps alone will open your content to a wider audience.
Accessibility isn‘t just about compliance — it’s about creating an inclusive digital world. As you embark on this journey, remember that each improvement you make will improve your web visitor's online experience.
Website Accessibility Checklist
This checklist will help you make the following more accessible on your website:
- Web Pages
- Navigation
- Video & Media
- And More!
Download Free
All fields are required.
