Decorative vs. informative images: when to write nothing

Somewhere in your template sits a little flourish — a wavy divider, a soft gradient blob, a swoosh behind the headline. You've committed to adding alt text to everything, so you dutifully describe it: "decorative orange wave divider." Now a screen reader user hears about your divider. Every section. That isn't accessibility; it's clutter.

Good alt text practice isn't "describe every image." It's "describe every image that carries meaning — and deliberately silence the rest." The second half is the part most teams have never been taught.

The two jobs an image can have

An informative image adds something the surrounding text doesn't: the product photo, the chart, the screenshot with the button circled, the graphic with a date baked into it. Take it away and the reader has lost information.

A decorative image is furniture: dividers, spacers, background textures, abstract shapes, the stock photo that merely restates the headline's mood. Take it away and the page loses atmosphere, not meaning.

The test is deletion. Imagine the image gone — would you need to add a sentence of text to compensate? If yes, it's informative: write alt text. If no, it's decorative: write nothing, on purpose.

"Nothing" is spelled alt="" — not a missing attribute

Here's where it gets technical for exactly one paragraph. Skipping the alt attribute and leaving it empty are opposite outcomes. When alt is missing entirely, screen readers try to be helpful and announce the image anyway — often by reading the filename: "wave underscore final underscore v2 dot P-N-G." An empty attribute — alt="" — is the W3C-endorsed signal that the image is intentionally decorative, and screen readers skip it as if it weren't there.

Most publishing tools do the right thing if you know what they're doing. WordPress, for instance, outputs an empty alt attribute when you leave the field blank, and its image block has an explicit decorative toggle. That cuts both ways: leave the field blank on an image that actually matters, and you've silently declared your product shot to be wallpaper.

On social, a blank field doesn't mean silence

One platform twist worth knowing: on Facebook and Instagram, leaving the alt field empty doesn't produce an empty alt. Meta's systems generate a machine description instead — the familiar "may be an image of two people and text." So you can't really opt into silence there, and you rarely need to: an image you chose to post in a feed is almost never decorative. If it was worth posting, it's worth describing.

A ten-second decision habit

Before each image, run three quick questions. Does it contain words the reader needs — a date, an offer, a headline? Then the alt text must carry them. Does it show something the text doesn't say? Describe that one thing. Neither? It's decoration: alt="" and move on.

That habit sorts the images; the remaining cost is writing good descriptions for the ones that matter. That's the half we built SnipAlt for — it writes the words for the images that need them, and the ten-second decorative call stays yours.