You probably already know that you need to make your images ADA compliant, so they are accessible to those with vision disabilities. Whether they are blind or have partial sight, you need to provide them with an alternative way to understand the content of your images.
The easiest way to do this is by adding alternative text, or ALT text, so that screen readers can describe your images out loud. For website photos, this means including a clear and descriptive “alt” attribute within your HTML image tag. Many platforms also make it easy with built-in fields for adding ALT text when you upload or edit an image.
If you’re working with documents like PDFs or slideshows, you can add ALT text there too. That way, anyone using a screen reader will hear a description of the image. You can also add descriptions to an image’s metadata (EXIF data), but keep in mind this has limited support and doesn’t replace proper ALT text.
When you add ALT text to the images on your website or in your documents, you make your content accessible to everyone while expanding your audience. Plus, if your images are online, ADA compliance isn’t optional. Public-facing content must meet accessibility standards, and skipping ALT text can leave you open to legal issues. Adding alt tags is just one of several steps you should take to protect your organization and meet ADA requirements.
There’s also an added bonus. Good ALT text helps boost your SEO (search engine optimization), which can help your website rank higher in search results by giving search engines more context about your images.
Let’s break down how to add ALT text to your images and what makes for an effective description.
How do you add ALT text to your images?
A common misconception is that ALT text is only for websites. In reality, it’s needed anywhere you use images, such as PDFs, Word documents, presentations, or even Google Docs.
Keep in mind that how you add ALT text all depends on the format you’re working with. That’s why I’ve put together some quick instructions below to help cover most of the formats you’re likely to encounter. Let’s dive in!
Adding ALT text on your website
Depending on how your website is built, the process for adding ALT text may vary. However, in every case, you’ll be adding a description so that screen readers can read your images out loud. Let’s look at how to do this on some of the most popular website platforms.
Adding ALT text in WordPress
If your website runs on WordPress, you have a couple of options for adding ALT text. You can manage images directly through the Media Library or edit the ALT text on individual pages, posts, or widgets where your images appear. The easiest approach is to add ALT text when you upload new images, but there are also plugins available to help you bulk update ALT tags on existing images.
After uploading an image to the Media Library, click on it to edit its properties. Enter a short description of that image in the “Alternative Text” input, as shown below.
If you purchased a stock image, it often includes a description within the image’s metadata that displays in the caption field. You can usually copy that text to use as your ALT text.
To edit the ALT text for an image directly within a page or post, click on the image you want to update and then click on the edit (pencil) icon that appears. This will open the “image details” dialog box, where you can add or change the Alternative Text.
When you’re finished, click the “update” button to save your changes.
Adding ALT text in Squarespace
Adding ALT text in Squarespace can be a little tricky compared to other platforms. Start by navigating to the page and finding the image you want to edit. Add a caption to the image (Squarespace uses this caption as the ALT text for screen readers). Once you’ve added your caption, open the Image Block’s Design tab, then choose an option or toggle to hide the caption so it won’t display visually and will only serve as ALT text.
After adjusting your settings, ensure that you save your changes so that your ALT text is properly applied.
Adding ALT text in HTML
Whether you’re using a website builder or coding in HTML, the goal is always the same: every important image should include a clear, descriptive “alt” attribute so screen readers can describe it to users who can’t see the image. For example, here’s a simple way to add ALT text directly in HTML:
<img src=”cute-kitten.jpg” alt=”Cute orange kitten sitting on a rock” />
This alt text makes the image accessible for people who rely on screen readers and helps search engines understand your content.
When working with complex images, such as charts or infographics, include concise alt text that describes the image’s content. Then, include a more detailed explanation nearby on the page (for example, in a paragraph directly below the image or linked from the image caption). Avoid using the outdated longdesc attribute, as it has been deprecated in HTML5 and isn’t supported by modern browsers or assistive technologies.
It’s also important to remember that CSS background images can’t include alt text because they’re not part of your HTML content. If your background image contains important information, use an HTML <img> tag instead. If that’s not possible, you can add a visually hidden element with descriptive text or use ARIA attributes like role=”img” and aria-label on a nearby empty element. However, these should only be used as a last resort when you can’t redesign the layout to include semantic HTML.
Adding ALT text in a PDF
To add ALT text to images in a PDF, you’ll need a PDF editor. The best option is Adobe Acrobat Pro, made by the company that created the PDF format. While Acrobat Pro offers the most reliable tools for accessibility, it does come with a monthly cost of around $19. If you don’t need all the advanced features, Acrobat Standard is a slightly more affordable alternative that still works well for adding ALT text.
There are also free PDF editors available online, but many of them don’t support adding tagged ALT text needed for proper accessibility. If you’d like to explore your options, you can check out TechRadar’s list of the best free PDF editors for 2025—just keep in mind that these tools may not meet ADA compliance requirements.
Since Adobe Acrobat Pro remains the industry standard for creating accessible PDFs, let’s focus on how to add ALT text using Acrobat here. While it may seem more complicated than it should be, it’s worth learning so that your documents can be accessible to everyone.
1. Open the Tools tab in Acrobat and select Prepare for Accessibility.
2. If your PDF hasn’t been tagged yet, click Automatically Tag PDF. This step ensures your document is structured correctly for accessibility.
3. Click on the image you want to edit. Then click Add Alternate Text in the left-hand panel.
4. In the dialog box that appears, enter a clear, concise description of the image.
Adding ALT text in Microsoft Word
Microsoft has made it surprisingly easy to add alternative text to images in Word. When you insert a new image, Word automatically generates ALT text for you. As you can see below, they were quite accurate. Even if it’s not quite right, you can quickly update it to make sure it clearly describes what’s shown.
For existing images, simply right-click (in Windows) and select “Edit Alt Text” from the context menu.
Adding ALT text in Microsoft PowerPoint
Adding ALT text in Microsoft PowerPoint is a quick and straightforward process. When you insert an image, the toolbar automatically switches to the Picture Format tab, where you’ll find an option labeled Alt Text. With your slide or image selected, click on Alt Text to review or update the description. Microsoft often generates ALT text automatically when you add an image, but it’s always a good idea to review it and make any necessary adjustments so that it accurately describes your content.
For existing images, you simply need to right-click (in Windows) and select Edit Alt Text from the context menu, or open the Picture Format toolbar and select Alt Text.
Adding ALT text in Microsoft Excel
Adding or updating ALT text in Microsoft Excel is a straightforward process. When you insert an image into your spreadsheet, Excel automatically switches to the Picture Format tab, where you’ll find the Alt Text option. Simply add your ALT text and you’re good to go.
If you’re updating an existing image, first select the image, then switch to the Picture Format tab to access the Alt Text field. Once there, you can enter or edit the description to make sure it accurately reflects what the image shows.
Adding ALT text in Google Docs
Google Docs makes it easy to add ALT text so your images are accessible to everyone. To get started, click on the image you want to describe, then right-click and choose Alt text from the context menu. This will open a window where you can enter a clear description of what the image shows. Once you’re done, just click OK, and your ALT text will be saved.
Keep in mind that Google Docs includes both a Title and a Description field for ALT text. While you can fill out both, it’s the description that’s usually used as ALT text, especially when exporting the document to Word format. To be safe, it’s a good idea to add your alternative description in both fields, so your content remains accessible regardless of how the file is shared or converted.
Adding ALT text directly to images through metadata
While you can’t actually add ALT text directly through an image’s metadata or EXIF data, you can add a title or description that some programs recognize in limited ways. For example, in Windows, you can add a title to an image that may be displayed as a caption on certain platforms.
When you upload an image like this into WordPress, it will often import the Title you set in the metadata and use it as the caption for the image. This doesn’t provide proper ALT text on its own, but it does give you a description you can copy and paste into the ALT text field.
That said, it’s hard to know which other programs use this information consistently, as support for metadata varies widely.
To add or edit metadata in Windows, simply right-click on your image file and select Properties, then navigate to the Details tab where you can enter a Title or Description. You can also update EXIF metadata using Mac programs or third-party software—both free and paid options are available. While metadata alone doesn’t make your images accessible, it’s a good practice to set this information, since future tools or platforms may use it to improve image descriptions.
What should ALT text say?
Now that you know how to add ALT text, what should it actually say? A good rule of thumb is to describe the image as you would to someone who can’t see it. You don’t need to write a full essay, just enough detail so that someone listening to your description has a clear idea of what the image shows.
For instance, consider this painting by Coolidge. A bad alt text would simply say “dogs.”
A better option would be “a painting of four dogs playing poker.”
And an even more descriptive alt text could be “1894 Coolidge painting of four dogs playing poker around a table.”
While you can certainly go into more detail for complex images, keep in mind that ALT text is generally meant for concise descriptions. If you need to provide a longer explanation, include it as nearby text on the page.
How do I optimize alt text?
Since search engines can’t see images, they rely on the ALT text you provide to understand what each image is about. That’s why writing thoughtful ALT text isn’t just good for accessibility; it can also help your website show up in search results. Including relevant keywords in your descriptions provides search engines with additional context about your images, which can drive more traffic to your site.
For example, if your website is about accessibility and ADA compliance, you’ll want to include key terms like “alt text” or “accessibility” in your image descriptions when they naturally fit. This not only helps people using screen readers understand what your images show but also signals to Google what your page is about, boosting your SEO.
Looking at this article, one might think it’s about cute little orange kittens since it has been included many times throughout. However, by including the terms “alt text” and “accessibility” within the alt text, it provides extra context for Google and those listening with screen readers. This, in turn, gives the images and pages more SEO value.
WARNING: Use keywords thoughtfully and sparingly. Overloading your ALT text with keywords can be frustrating for people using screen readers and may even lead to search engines penalizing your site for spammy practices. Always write ALT text primarily for people, not search engines, and keep your descriptions clear, concise, and relevant.
AI-generated alt text
Many website platforms and plugins now offer AI-generated ALT text that automatically creates descriptions for your images. While this can save time, it’s essential to always review and edit these AI-generated descriptions for accuracy and context. Automated tools can easily miss important details, provide vague or irrelevant information, or even produce misleading descriptions that don’t match what your image actually shows. Taking a moment to double-check these tags ensures your images stay accessible and meaningful for everyone who relies on a screen reader.
For complex visuals like charts, graphs, or infographics, remember that a brief ALT text alone won’t give users the full picture. Always pair concise ALT text with a nearby, detailed text explanation so everyone can fully understand the information your image conveys.
In summary
You’ve now learned how to add ALT text to your images and why it matters for accessibility and SEO. The key is to make adding ALT text a regular part of your process as you upload or insert images, rather than putting it off until later. By taking this simple step, you’ll ensure your images are accessible to everyone and easily discovered by search engines.