How to Check if an Image Has Alt Text (4 Easy Methods)

Why Alt Text Matters

Alt text (alternative text) is a short written description added to an image in HTML via the alt attribute. It serves two critical purposes: it allows screen readers to describe images to visually impaired users, and it gives search engines context to understand what an image depicts.

Under WCAG 1.1.1 (Non-text Content), all meaningful images must have descriptive alt text to achieve Level A conformance. Missing or empty alt text on informational images is one of the most common accessibility violations found on the web today.

So how do you actually check whether an image has alt text? Here are four reliable methods.

Method 1: Inspect the Page Source (View Source)

The simplest way to check alt text is to view the raw HTML source of a web page:

1. Open the page in your browser.
2. Right-click anywhere and select View Page Source (or press Ctrl+U / Cmd+U).
3. Use Ctrl+F / Cmd+F to search for <img.
4. For each image tag, look for the alt attribute. For example: <img src="photo.jpg" alt="A woman reading a book in a library">

If the alt attribute is missing entirely, or if it's present but empty (alt=""), that image may need attention. Note that alt="" is intentionally used for decorative images that don't carry meaning — this is valid and correct per WCAG.

Method 2: Use Browser Developer Tools (Inspect Element)

For a faster, more visual approach, use your browser's built-in developer tools:

1. Right-click directly on the image you want to check.
2. Select Inspect or Inspect Element.
3. The DevTools panel will open with the image's HTML highlighted.
4. Look for the alt attribute in the highlighted <img> tag.

This method is especially useful when you want to check a specific image quickly without searching through the full page source. You can also hover over the image element in the Elements panel to see a preview, and the alt value will be visible inline.

Method 3: Use the WAVE Accessibility Tool

The WAVE Web Accessibility Evaluation Tool (available as a free browser extension or at wave.webaim.org) provides a visual overlay on your page that flags accessibility issues, including missing alt text.

1. Install the WAVE browser extension (Chrome or Firefox).
2. Navigate to the page you want to check.
3. Click the WAVE extension icon.
4. WAVE will overlay icons on the page — a red icon marked with an exclamation point indicates a missing alt text error on an image.
5. Click any icon for more details about the specific issue.

WAVE also displays a summary count of errors, which makes it easy to see at a glance how many images on the page are missing alt text.

Method 4: Use Alt Audit for a Sitewide Check

The three methods above are great for checking individual images or pages, but what if you need to audit your entire website at once? That's where Alt Audit comes in.

Alt Audit scans your entire site and generates a comprehensive report of every image that is missing alt text, has an empty alt attribute (where it shouldn't be), or has alt text that may be too short, too long, or auto-generated. This saves hours of manual work and gives you a prioritized action list for fixing your accessibility issues.

With Alt Audit, you can:

• Scan thousands of images across your entire domain in minutes.
• See exactly which pages and images are missing alt text.
• Use AI-powered suggestions to generate descriptive alt text automatically.
• Track your progress over time as you fix issues.

What Makes Good Alt Text?

Once you've identified images missing alt text, you'll want to write effective descriptions. Here's what good alt text looks like:

• Be descriptive and specific: "Golden retriever puppy playing in autumn leaves" is far better than "dog" or "photo".
• Keep it concise: Aim for under 125 characters. Screen readers may cut off longer alt text.
• Don't start with "Image of" or "Photo of": Screen readers already announce that it's an image. Just describe what it shows.
• Reflect context: The same image might need different alt text depending on the surrounding content. A graph on a data page should describe the data trend, not just "bar chart".
• Use empty alt for decorative images: If an image is purely decorative and adds no information, use alt="" to tell screen readers to skip it.

Common Alt Text Mistakes to Avoid

When auditing your images, watch for these frequent errors:

• Missing alt attribute entirely: Some older CMS systems or third-party plugins may output <img> tags without any alt attribute at all.
• Filename as alt text: Alt text that reads "IMG_4823.jpg" or "banner-image-v2-final.png" is not helpful to anyone.
• Keyword stuffing: Loading alt text with keywords for SEO purposes ("best cheap shoes buy shoes online cheap shoes") is a poor accessibility practice and may be penalized by search engines.
• Identical alt text on different images: If multiple images on a page have the same alt text, screen reader users won't be able to distinguish between them.

Start Checking Your Alt Text Today

Whether you're a developer, content manager, or SEO specialist, knowing how to check if an image has alt text is a fundamental skill for building accessible, high-performing websites.

For a fast, thorough, and scalable solution, Alt Audit gives you complete visibility into your site's alt text coverage — so you can fix issues faster and stay compliant with WCAG standards.