What should I write in the alt text for a featured image?

Describe what the image actually shows, in one plain sentence, the way you would describe it to someone over the phone. Something like "a single tree on a misty hillside at dawn" tells Google and a screen reader exactly what they are looking at. Skip "image of" and skip the keyword stuffing - a real description does more for both search and accessibility than a jammed-in phrase ever will.

What is the difference between alt text and a caption?

Alt text describes the image for people and crawlers who cannot see it, and it lives in the HTML alt attribute where most readers never notice it. A caption is visible text printed under the image that everyone reads, usually for credit or context. They serve different jobs, so write both when both earn their place, and do not just copy one into the other.

How long should alt text be?

One sentence, roughly 8 to 16 words. Long enough to describe the subject and the scene, short enough that a screen reader does not drone through a paragraph. If you find yourself writing two sentences, the second one is usually a caption in disguise - move it out of the alt attribute.

Alt Text for Featured Images - What to Write

Alt text for a featured image is a plain one-sentence description of what the image shows, written the way you would describe it to a person. Describe the picture the way you would to someone on the phone, and that same sentence doubles as your Google Images win and your accessibility win. That is the whole answer. The rest is what “describe it” actually looks like, and the few ways people get it wrong.

The reason this matters more than it looks: the alt text on your cover is the one piece of featured-image SEO that touches search directly. Everything else a cover does - winning the click, filling the link preview - is indirect. Featured images barely move your ranking on their own, but the alt attribute is the line a crawler actually reads. So it is worth getting right, and it takes about ten seconds.

What good alt text sounds like

Picture the image. Now say what it is, out loud, in one breath. That sentence is your alt text.

For a cover, that usually means naming the subject and the scene: “a single tree on a misty hillside at dawn,” or “a flat-lay of a laptop and coffee on a wooden desk,” or “the words ‘Win the click’ over a dark amber ink texture.” If your cover has a headline baked into it, include that headline in the alt - a screen reader user should hear the words on the image, because those words are part of what the image communicates.

The test is simple. If someone read your alt text aloud and you could roughly picture the cover from it, you nailed it. If it could describe a thousand different images, it is too vague.

Two habits keep it clean:

Drop “image of” and “photo of.” The alt attribute already means “this is an image.” Starting with “image of a tree” is like a road sign that says “this is a sign.” Just write “a tree on a misty hillside.”
Write it once, in plain words. No comma-jammed list of keywords, no brand name wedged in where it does not belong. One human sentence beats a stuffed one for both search and a screen reader, every time.

Alt text and a caption are two different things

People mix these up constantly, so here is the split.

	Alt text	Caption
Where it lives	the HTML `alt` attribute	visible text under the image
Who reads it	screen readers, crawlers, anyone when the image fails to load	every reader on the page
Its job	describe what the image shows	add context, credit, or commentary
Typical content	“a single tree on a misty hillside at dawn”	“Photo by Jane Doe” or a line of context

A caption is read by everyone and is usually about the image (who shot it, why it is here). Alt text stands in for the image when it cannot be seen. They overlap sometimes, but copying your caption into the alt attribute is a miss - “Photo by Jane Doe” tells a blind reader nothing about what is in the picture.

If your cover photo came from a stock site, put the photographer credit in a caption and keep the alt for describing the picture. Keep the two jobs separate and write each for its own audience.

Keyword stuffing is the mistake that backfires

The tempting move is to treat the alt attribute as a free slot for your target keyword. “best blog featured image seo 2026” feels productive. It is the one thing that can actually hurt you.

Google has been clear that stuffed alt text reads as spam, and a screen reader user gets a wall of keywords instead of a description, which is its own small cruelty. The alt text on a cover should describe the cover. If your keyword honestly describes what the image shows, great, it lands there naturally. If you are reverse-engineering the sentence to fit a phrase, stop - you are optimizing for a crawler that already discounts the trick.

Alt text describes what the image shows. Write it about the picture itself, and let a keyword land only when it honestly fits.

The same logic kills the keyword-jammed filename next to it. Name the file misty-hillside-tree.webp, write alt text that matches, and you have given Google a clean, honest signal it can trust. That is the whole game.

Decorative versus meaningful: when to leave it empty

Not every image needs a description, and forcing one on a purely decorative image only makes things worse.

A featured image is almost always meaningful - it represents the post, it is the thing people see in the feed and the share card, so it gets real alt text. But a background flourish, a divider line, a texture that carries no information should have an empty alt attribute (alt=""), not a missing one. An empty alt tells a screen reader to skip the image cleanly. No alt at all makes the screen reader read out the filename, which is the worst outcome of the three.

So the rule is short:

Featured image, photo, anything that carries meaning - write a one-sentence description.
Pure decoration that adds no information - empty alt (alt=""), and move on.

When you are unsure, ask whether a person who cannot see the image would miss anything if it vanished. If yes, describe it. If no, empty alt.

A quick checklist before you publish

Describe the subject and scene in one plain sentence.
Include any headline text that is baked into the cover.
Drop “image of” and “photo of.”
Keep it to one sentence, roughly 8 to 16 words.
No keyword stuffing, no brand name wedged in.
Put the photographer credit in a caption and keep the alt for the description.
Use an empty alt="" only for genuinely decorative images.

That is the entire job. Alt text is the quiet part of a cover that earns its keep with search and respects the readers who cannot see the picture, and it costs you one honest sentence. While you are at it, the rest of what makes a featured image worth the click is where the bigger payoff sits - the alt text just makes sure the work gets found.

The cover on this post was built in Lede, and the alt text above is the real sentence I wrote for it. When you want to make a cover worth describing, open the editor or start from a gallery template - then describe the picture in one plain line and ship it.