Useful alternative text does not replace a file name with a row of keywords. It gives a reader who cannot see the image the information needed for the current task. W3C accessibility guidance stresses that the correct text depends on purpose. The same Qilin image might demonstrate horns and hooves in an article, distinguish a color option on a product page, or add no information when used as a decorative background.
Begin by asking what the reader loses if the image disappears. A wallpaper preview can name its subject, composition, background, and safe area: “Dark blue phone lock-screen preview with a gold Xuanwu in the lower third and open space for the clock above.” A cultural diagram can add the identity cue: “Xuanwu shown as an entwined tortoise and snake.” Do not present invisible symbolism as a visible fact or add claims such as “brings luck.”
Cultural names support both comprehension and discovery, but they should not become a tag cloud. “Qilin Pixiu Bai Ze Xuanwu Chinese beast wallpaper” describes no image. Select the correct subject and pair it with observable features. If the identity is debated, attribute it: “Winged jade beast catalogued by the museum as bixie.” Attribution is more useful than manufactured certainty.
Common contexts require different choices. A linked image’s alt text explains the destination or action. A product image distinguishes the version being selected. An image that merely repeats nearby content receives empty alt text so a screen reader can skip it. A complex teaching diagram needs a longer explanation in adjacent body text rather than an entire essay inside one attribute.
Finish with a deletion test: remove adjectives and search phrases, then ask whether the task information remains. Read the page in sequence to catch repetition with the caption or heading. Accurate alt text gives sighted readers, screen-reader users, and search systems one coherent account of the image rather than three competing descriptions.