How to Fix Missing Alt Text on Images to Improve SEO and Accessibility

Missing alt text on your images is one of those sneaky SEO problems that quietly costs you traffic every single day. Search engines can't "see" your images the way humans do — they rely on alt text to understand what's in a photo, graphic, or diagram. When that text is missing, you're leaving ranking opportunities on the table and making your site harder to use for people who rely on screen readers. The good news? Learning how to fix missing alt text images for SEO is straightforward, and you can make meaningful progress in an afternoon.

Why Alt Text Matters for SEO and Accessibility

Before we get into the fixes, let's make sure we understand what's actually at stake.

For SEO: Google uses alt text to index your images and determine when to show them in Google Image Search. Alt text also adds contextual signals to your page, reinforcing what the page is about. A product photo with no alt text is a missed keyword opportunity. One with a descriptive, relevant alt tag helps Google connect your content to search queries.

For accessibility: Screen readers — software used by people who are blind or have low vision — read alt text aloud to describe images. Without it, those users hear something unhelpful like "image_0042.jpg." That's a frustrating experience, and in some industries, missing alt text can create legal compliance issues under accessibility laws like the ADA.

So fixing this isn't just an SEO checkbox. It's the right thing to do for your users.

How to Find Images with Missing Alt Text

You can't fix what you can't find. Here are three practical ways to identify the problem.

Option 1: Use an SEO Audit Tool

Tools like Abby SEO, Screaming Frog, or Ahrefs Site Audit will crawl your site and flag every image missing an alt attribute. This is the fastest method, especially if you have a large site with hundreds of pages.

Option 2: Inspect Your Page Manually

Right-click any image on your site and select Inspect (in Chrome or Firefox). In the HTML panel, look for the <img> tag. You'll see something like this:

<!-- Image WITH alt text ✅ -->
<img src="golden-retriever-puppy.jpg" alt="Golden retriever puppy playing in the grass">

<!-- Image MISSING alt text ❌ -->
<img src="golden-retriever-puppy.jpg">

<!-- Image with empty alt text (intentional, for decorative images) ✅ -->
<img src="divider-line.png" alt="">

If the alt attribute is completely absent or left blank on a meaningful image, that's a problem you need to fix.

Option 3: Run a Browser Extension Check

Extensions like Web Developer or axe DevTools (free Chrome extensions) can highlight all images on a page and flag the ones missing alt text in seconds.

How to Write Good Alt Text (Not Just Any Alt Text)

Finding missing alt text is step one. Writing effective alt text is step two. There's a difference between technically having alt text and having alt text that actually helps you.

Do this:
- Describe the image specifically and accurately
- Include your target keyword naturally when it genuinely fits the image
- Keep it under 125 characters
- Write it like a sentence, but skip the period at the end

Avoid this:
- Keyword stuffing ("alt text SEO fix alt text missing images fix SEO")
- Generic descriptions ("image," "photo," "picture")
- Repeating the surrounding text word-for-word

Example comparisons:

How to Fix Missing Alt Text by Platform

Here's where the rubber meets the road. The fix looks different depending on what platform your site is built on.

WordPress

1. Go to Media > Library in your WordPress dashboard
2. Click on any image
3. On the right-hand panel, you'll see an Alt Text field
4. Type your descriptive alt text and click Update

For images already placed in posts or pages, go to the page editor, click on the image, and update the alt text field in the block settings panel on the right.

Shopify

1. From your Shopify admin, go to Products (or Pages, Blog Posts, etc.)
2. Click on the relevant product and find the image
3. Click on the image and select Edit alt text
4. Enter your description and save

Squarespace

1. Click on the image block in your editor
2. Select Edit
3. Navigate to the Image tab and find the Alt text field
4. Add your description and apply changes

Custom HTML Site

If you're working directly in HTML, find your <img> tags and add or update the alt attribute:

<!-- Before -->
<img src="/images/seo-checklist.png">

<!-- After -->
<img src="/images/seo-checklist.png" alt="Printable SEO checklist for small business owners">

If you use a CMS with a database (like a custom WordPress theme or a headless setup), you may need to update alt text through your content management interface or directly in the database. If that feels over your head, this is a good task to hand off to your developer.

A Note on Decorative Images

Not every image needs descriptive alt text. If an image is purely decorative — like a background pattern, a divider line, or an icon that adds no meaning — use an empty alt attribute (alt=""). This tells screen readers to skip it, which actually improves the accessibility experience.

The key distinction: Does this image communicate information the user needs? If yes, write alt text. If no, use alt="".

Prioritize Your Fixes

If you have a large site and you're overwhelmed by the sheer number of missing alt text issues, prioritize in this order:

1. Product images or service images — highest SEO and conversion value
2. Blog post images — especially the featured image and any images that illustrate key points
3. Homepage images — high visibility, often overlooked
4. Navigation icons and logos — lower priority, but still worth addressing

Make It a Habit Going Forward

The best time to add alt text is when you're uploading the image in the first place. Build it into your content workflow: every time you add an image to a page, post, or product listing, alt text gets written before you hit publish. It takes 15 seconds and saves you from having to audit and fix it later.

Ready to find out exactly how many images on your site are missing alt text — and what else might be quietly hurting your rankings?

Run a free SEO scan at abbyseo.com. You'll get a full breakdown of your site's issues, and for just $8.99, you'll receive a personalized remediation guide with clear, prioritized steps to fix everything — including how to fix missing alt text images for SEO — so you can stop guessing and start improving.