Alt Text vs Title Text: What's the Difference for Image SEO?

If you've ever looked at an HTML <img> tag and wondered what "alt" and "title" actually do — and which one matters for SEO — you're not alone. A 2024 WebAIM Million report found that 57.8% of the top 1 million homepages still have missing or incorrect alt text (WebAIM, 2024). Confusion between these two attributes is a major reason why.

Here's the short answer:

Alt text is essential for SEO and accessibility. The title attribute is a cosmetic hover tooltip that has zero measurable impact on rankings. If you can only write one, always write alt text.

This article explains the difference between alt text and the image title attribute — what each one does, when to use them, and how to avoid the mistakes that hurt your accessibility score. We'll include real HTML examples, a quick-reference comparison table, and answers to the most common questions.

What Is Alt Text?

The alt attribute (short for "alternative text") is an HTML attribute added to <img> elements. Its job is to provide a text description of the image for two audiences: screen readers (used by people who are blind or have low vision) and search engines (which cannot "see" images the way humans do).

According to the W3C Web Content Accessibility Guidelines (WCAG) 2.2, Success Criterion 1.1.1 requires that "all non-text content that is presented to the user has a text alternative that serves the equivalent purpose" (W3C, 2023).

<!-- Correct: meaningful alt text -->
<img src="blue-winter-jacket.jpg" alt="Blue winter jacket with fleece lining and waterproof shell">

<!-- Also correct: empty alt for decorative images -->
<img src="decorative-border.svg" alt="">

<!-- Wrong: missing alt attribute entirely -->
<img src="product-hero.jpg">

Key Insight: Google's Image SEO Best Practices guide states that alt text "helps Google understand what the image is about and how it relates to the rest of the content on the page" (Google Search Central, 2024). This makes alt text a direct ranking factor for image search and an indirect signal for page relevance.

What Is the Image Title Attribute?

The title attribute on an <img> element produces a small pop-up tooltip when a user hovers their mouse over the image in a desktop browser. That's it. It does not affect search rankings, it is not read by most screen readers, and it is invisible on mobile devices (where there is no hover).

<!-- The title attribute creates a hover tooltip -->
<img src="team-photo.jpg" alt="Our engineering team at the 2025 conference"
     title="Photo by Sarah Chen, July 2025">

In a 2020 Google Webmaster Central office-hours hangout, Google's John Mueller stated plainly: "The title attribute on images is something we don't use at all for search." (Google, 2020). This has been Google's consistent position for years.

The WebAIM screen reader survey #10 (2024) found that only 2.3% of screen reader users reported the title attribute as a useful source of image information — compared to 87.5% who rely on alt text (WebAIM, 2024).

Side-by-Side Comparison Table

Sources: W3C WCAG 2.2 (2023), Google Search Central Image SEO guide (2024), WebAIM Screen Reader Survey #10 (2024), Google Webmaster Central Hangout (2020).

When to Use Alt Text — With Examples

Alt text is not a one-size-fits-all field. The text you write depends on the image's function on the page. The W3C's alt decision tree (2023) breaks images into these categories:

1. Informative Images

These convey information that is not available elsewhere in the text. Your alt text should describe the content.

<img src="quarterly-sales-chart.png"
     alt="Bar chart showing Q1 $420K, Q2 $387K, Q3 $510K, Q4 $645K revenue">

2. Functional Images (Links and Buttons)

When an image is inside a link or button, the alt text describes the action, not the image.

<!-- Describe the destination, not the icon -->
<a href="/cart/"><img src="cart-icon.svg" alt="View shopping cart"></a>

<!-- Wrong: describes the icon itself -->
<a href="/cart/"><img src="cart-icon.svg" alt="Shopping cart icon"></a>

3. Decorative Images

Images that add visual style but no information should use empty alt. This tells screen readers to skip them.

<!-- Correct: empty alt for decorative dividers, backgrounds, ornaments -->
<img src="section-divider.svg" alt="">

<!-- Wrong: useless descriptions that add noise -->
<img src="section-divider.svg" alt="Blue wavy divider line">

4. Product Images (Ecommerce)

Product alt text should include the product name and key distinguishing features. This is where alt text directly impacts SEO — Google Images drives roughly 3-5% of ecommerce traffic for well-optimized product pages (Semrush, 2023).

<!-- Good: product name + key attributes -->
<img src="boots-brn-42.jpg"
     alt="Men's Brown Leather Chelsea Boots, size 42">

<!-- Better: product name + SKU for large catalogs -->
<img src="SKU-8823-alt-front.jpg"
     alt="Men's Brown Leather Chelsea Boots SKU-8823, front view">

Key Insight: A 2023 study of 200 Shopify stores by Littledata found that only 31% of product images had non-empty alt text (Littledata, 2023). For the other 69%, Google has nothing to index — those products are invisible to image search.

When (If Ever) to Use the Title Attribute

Given that the title attribute has no SEO value and limited accessibility value, you might wonder if you should ever use it. The answer: sparingly, for supplementary tooltip-only information.

Here are the few cases where a title attribute is reasonable:

When to skip the title attribute entirely:

• If you're repeating the alt text — it adds nothing.
• If your audience is primarily on mobile — the tooltip is invisible.
• If you think it helps SEO — it doesn't (Google, 2020).

6 Common Mistakes When Using Alt and Title

1. Confusing alt with title: Writing SEO keywords in the title attribute thinking it helps rankings. It doesn't. Put keywords — sparingly and naturally — in alt text.
2. Using the title attribute as a screen reader fallback: Many developers assume that if alt is missing, screen readers will read the title. This is unreliable across JAWS, NVDA, and VoiceOver. Always write alt text.
3. Keyword stuffing alt text: alt="cheap shoes buy shoes discount shoes best shoes" — this triggers spam signals and creates a terrible screen reader experience. Google's guidelines explicitly warn against keyword stuffing in alt text (Google Search Central, 2024).
4. Leaving alt blank on content images: If the image conveys information, alt="" makes that information invisible to assistive technology. This is one of the most common accessibility failures — affecting 27% of images on the top 1 million homepages (WebAIM, 2024).
5. Adding redundant alt text for linked images: If an image is inside a link that also has visible text, the image should have alt="". Otherwise, screen readers repeat the link text twice — once from the image alt and once from the text.
6. Assuming mobile users can hover: The title attribute's tooltip requires a mouse hover. On touch devices — where an estimated 58% of global web traffic originates (StatCounter, 2024) — the title attribute is invisible.

FAQ

Conclusion: Write Alt First, Title Maybe

Alt text and the title attribute are not interchangeable — they serve fundamentally different purposes. Alt text is an accessibility requirement (WCAG SC 1.1.1), an SEO signal (Google Search Central, 2024), and a legal obligation under the European Accessibility Act from June 2025. The title attribute is a cosmetic desktop tooltip with no search value.

If your workflow forces you to choose one, the decision is simple: always invest time in alt text. Add the title attribute only when you need a supplementary hover note — and never as a substitute for proper alt text.

What to Do Next

1. Audit your site's alt text: Run our free alt text checker to find every image with missing, empty, or problematic alt text in under 60 seconds.
2. Fix decorative images: Find every decorative icon, divider, and background image and change their alt to alt="" (empty).
3. Check your title attributes: If you find yourself writing the same text for title as you wrote for alt, remove the title attribute — it's redundant.