Image Alt Text for SEO: Rules That Still Hold

Image Alt Text for SEO: Write It for Humans, Not for a Keyword Tool

26 August 2026 · 5 min read · By Milvydas

Framed photographs on a dark gallery wall, some with gold plaques and some with empty slots

A missing plaque is a missing description. The picture can still hang; the visitor in the dark gets nothing.

Alt is an HTML attribute. It is what a screen reader speaks, and what Google has to go on when the image is shown in Google Images. Those two jobs are the same job if you write like a human.

Alt describes the image for someone who cannot see it. Keyword stuffing “best SEO coat London” helps nobody and looks like spam.

The rules that survive 2026

Describe what is in the frame, in the words you would use on the phone to a colleague.
If the image is a button or a linked logo, the alt is the destination or the brand name — not “logo.”
If the image is purely decorative, alt="". Do not skip the attribute; skip the words.
Do not start with “Image of.” The software already knows it is an image.
One or two facts beat a paragraph. Long alt is for complex diagrams, and even then a proper caption is kinder.

Product photos

The filename can be navy-wool-coat.jpg. The alt should still be a sentence a shopper would recognise. Colour, material, distinctive detail. That is how image search and accessibility line up.

Find the gaps

Our alt text checker reports coverage on the page we crawl — how many images have useful alt versus empty or missing. It cannot tell you if the text is a good description; you still read a sample. Fix templates first: one missing alt in a product card is every product in the catalogue.

Frequently asked

Is missing alt a ranking penalty?

Not as a sitewide penalty. You lose Google Images eligibility on that file, and you fail accessibility. On a product grid that can be a lot of traffic. On a background texture, empty alt is correct.

Should every image have alt text?

Every meaningful image should. Decorative images should have alt="" so screen readers skip them. Missing and empty are different.