The HTML alt attribute is required and reliable. The HTML title attribute is optional and unreliable. They look like they do similar jobs, but they don't.

If you're choosing between them, the answer is almost always alt text alone. The title attribute has narrow, niche use cases that most websites can ignore entirely. This guide explains why, with concrete examples.

Quick Answer

• Use alt. Every <img> needs it. Screen readers always read it.
• Skip title. It's a hover tooltip. Doesn't work on mobile. Inconsistent across screen readers. Adds noise without value.
• Exception: title on links (not images) is occasionally useful for "this opens in a new window" hints. Even then, most accessibility experts recommend visible UI hints instead.

What Each One Actually Does

The alt attribute

<img src="logo.png" alt="AltText.ai home">

Required by the HTML spec. Read aloud by every screen reader. Parsed by every search engine. Falls back as visible text if the image fails to load. Used by AI assistants to understand the image. Strong, predictable, universal. Full primer: What Is Alt Text?.

The title attribute

<img src="logo.png" alt="AltText.ai home" title="Click to go home">

Optional. Renders as a tooltip when a mouse hovers over the element. Has no effect on touch screens. Screen readers handle it inconsistently — some read it, some don't, and the spec doesn't require them to. Search engines mostly ignore it.

Why the Title Attribute Fails Modern Web

It doesn't work on mobile

Touch screens don't have hover. There's no way to trigger a title tooltip on a phone or tablet. If your title attribute carries information that isn't elsewhere, half your users (more, on consumer sites) never see it.

Screen readers handle it inconsistently

NVDA, JAWS, and VoiceOver each treat the title attribute differently — sometimes reading it after the alt text, sometimes only when configured to, sometimes never. The HTML Accessibility API Mappings spec discourages relying on it.

It's usually redundant

If the title attribute would say something useful, the alt text should already be saying it. Or it should be visible text on the page. Stuffing it into a hover-only tooltip means it's there for nobody — sighted users on mobile, screen reader users, search engines.

When (Rarely) to Use Title

Three narrow cases where the title attribute is occasionally useful:

1. Form fields where a label isn't visible. Better to make the label visible — but if you can't, title on the input becomes the accessible name.
2. iframes that need a label. An iframe without a label is unidentifiable to screen readers; title is the accessible-name fallback.
3. Disambiguating links with the same visible text. Two "Read more" links pointing to different articles can use title to differentiate. Better solution: rewrite the visible link text.

Note that none of these involve images. For images, alt alone is the right choice.

A Common Bad Pattern

<img src="bedroom.jpg"
     alt="Master bedroom"
     title="bedroom interior with king bed and white linens">

The information that should be in alt text is buried in the title attribute, where most users will never see it. Fix: move the descriptive content to the alt attribute.

<img src="bedroom.jpg"
     alt="Master bedroom interior with king bed, white linens, and morning light from the south-facing window">

Bottom Line

The choice between alt text and title attribute is almost always alt text. Title attributes are a pre-mobile-web hold-over that mostly hurt accessibility when misused. Put your descriptions in the alt attribute, where everyone — sighted users, screen reader users, search engines, and AI assistants — can use them.

For deeper context: What Is Alt Text?, Common Alt Text Mistakes, Alt Text vs Caption.

If you have more images than you can describe by hand, AltText.ai generates alt text in 130+ languages and writes it back to your CMS. Free crawl shows your gap.