Does the alt attribute of images really serve as a link anchor for SEO?

What is the primary function of the alt attribute according to Google?

The alt attribute (alternative text) was created to describe what an image visually depicts. Period. It is primarily an accessibility element: screen readers read it aloud for visually impaired users, and it displays if the image fails to load.

Google emphasizes this descriptive function because too many sites misuse alt as a primary SEO tool. We still see alt="best divorce lawyer Paris 16 cheap" on photos of law offices. This is not what Google wants — and most importantly, it does not help the user who cannot see the image.

In what situations does the alt attribute contribute to anchor text?

When an image is wrapped in an <a> tag (clickable link), the browser and search engines consider this image as a navigation element. In this specific context, the alt attribute indeed plays a role similar to traditional anchor text: it indicates the destination of the link.

But — and this is the crux of Mueller's statement — this anchor function remains secondary. The alt must always describe the image first and foremost. If your clickable logo leads to the homepage, alt="Company X Logo" is entirely sufficient. There’s no need for alt="Home | SEO Services | Paris Digital Agency".

Why is Google emphasizing this today?

Because old SEO practices persist. For years, stuffing alt with keyword phrases was a classic over-optimization technique. Google has gradually refined its algorithms to detect such abuses — and importantly, to better understand the visual context of an image through AI (object recognition, semantic analysis of the page).

By reminding this simple rule, Mueller aims to refocus practices that harm user experience and can even lead to manual penalties for spam in some cases. A descriptive and natural alt remains the best approach — both for accessibility and for ranking purposes.

• The alt attribute serves primarily to describe the image for accessibility and in cases where the image does not load.
• When the image is a link, alt contributes to anchor text — but this is not its primary function.
• Over-optimizing alts with keywords is counterproductive: Google prefers natural and factual descriptions.
• Google's AI is increasingly understanding visual content: a keyword-stuffed alt does not add any extra value.
• A good alt helps users and engines: it's an accessibility element, not an isolated SEO lever.

Is this statement consistent with what we observe on the ground?

Yes, completely. A/B tests have shown for several years that a descriptive and accurate alt performs better than a keyword-stuffed alt. Google Images favors pages where the alts genuinely match the visual content — which makes sense, since the algorithm can now compare the text to what it 'sees' through image recognition.

However, the impact of anchor text via alt remains limited. If your image link leads to a strategic internal page, a well-chosen alt can contribute to semantic linking — but this is marginal compared to an actual text link with optimized anchor text. Don't count on alts to compensate for weak internal linking.

What are the gray areas of this statement?

Mueller remains vague on the actual weight of alt as a ranking signal. We know that Google uses it to index and rank images in Google Images — but what influence does it have on page ranking in classic search? [To be verified] Public data is scarce. Correlations exist, but the isolated effect of alt, apart from other on-page signals, remains difficult to quantify.

Another point: Mueller does not specify how to handle decorative images (icons, visual separators, background images in CSS). The good WCAG practice recommends an alt="" empty for these elements — but some SEOs fear Google may misinterpret this absence. In reality, an empty alt on a decorative image is preferable to a generic useless alt.

Should you review all the alt attributes on your site?

Only if your alts are over-optimized or generic. If you have alt="image1.jpg" or alt="buy cheap running shoes with free delivery", then yes, an audit is necessary. Focus on strategic pages: product pages, landing pages, editorial content with illustrative images.

For a site with 10,000 pages, automating alt writing is tempting — but be wary of tools that generate keyword-first formatted text. Prioritize a factual description: "Man running on a forest trail" rather than "running trail nature sport endurance performance". If automation is unavoidable, at least calibrate your templates to sound natural.

How to write an alt attribute that meets Google's expectations?

Ask yourself a simple question: if I had to describe this image over the phone to someone who cannot see it, what would I say? Describe the main subject, the action if relevant, the context if necessary. Avoid empty phrases like "image of" or "photo of" — get straight to the point.

Practical example: a photo of an e-commerce product. Instead of alt="Nike Pegasus 40 black men's running shoes" (correct factual description), some write alt="Buy cheap Nike Pegasus 40 black men's running shoes promo". This is precisely what Mueller advises against: the alt should not be a commercial anchor, but a visual description.

What if the images are links and part of internal linking?

If your image is clickable, the alt should indicate what the image shows, not necessarily the destination of the link. For example: a visual from a blog article with a link to the article. The alt describes the visual ("Graph showing organic traffic evolution over 12 months"), not the article title. If you want to reinforce the semantic anchor, add an adjacent text link with optimized anchor text — this is cleaner and more effective.

For clickable logos in the header (a classic case), a simple alt="Logo [Company Name]" is sufficient. There’s no need for alt="Return to home | [Company Name] | SEO Services". Google understands very well that a logo in the header leads to the homepage — and the HTML context (the <header> tag, position in the DOM) already provides this information.

What tools to use to audit and correct alt attributes?

A crawl with Screaming Frog or Oncrawl allows you to extract all the alts in just a few minutes. Filter for images without alt, empty alts on content images (not decorative), and suspicious alts (too long, stuffed with keywords, repetitive). Export the list, prioritize strategic pages, and correct manually or via templates if you have a structured CMS.

For WordPress sites, plugins like SEO Framework or Rank Math can partially automate — but stay vigilant: automation often generates overly uniform formatted alts. If you have an editorial team, train them to write alts simultaneously with the content — it's the most natural time to do it, when the image is selected and integrated.

• Describe what the image shows, not what you want to sell or where the link leads.
• Keep alts short (10-15 words maximum) and factual.
• Avoid repeating keywords in the alt and in the immediately adjacent text.
• Leave the alt empty (alt="") for purely decorative images.
• Regularly audit strategic pages for missing or over-optimized alts.
• Train your writers to integrate the alt during content creation, not in post-production.