Writing & StyleStyle guide

Writing Image-Alternative Decisions by Purpose

Writing Image-Alternative Decisions by Purpose records a distinct W3C-supported accessibility writing task while keeping implementation mechanics outside the writing guidance.

Quick answer

Choose the image alternative from what the image is doing in context: convey information, perform a function, reproduce text, present complex information, repeat nearby text, or decorate.

Key details

Core IssueW3C WAI’s alt decision tree chooses image text-alternative treatment from the image’s purpose, function, redundancy, and surrounding context.
Registerweb accessibility and interface content

Important caveats

Scope Boundary

The same image can need different treatment in different contexts; this guide is a decision framework, not a fixed alt-text phrase generator.

Further guidance

Content

Decide what text alternative to write only after determining whether the image is informative, functional, text-bearing, complex, redundant, or decorative in that specific context.

Purpose

Purpose-first classification prevents authors from writing literal descriptions when the image instead needs a functional label, equivalent information, or no spoken alternative at all.

Sources and evidence

Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.

  1. An alt Decision Tree — W3C WAI Images Tutorial (opens in a new tab)World Wide Web Consortium (W3C) Web Accessibility Initiative · W3C WAI decision guidance for choosing text-alternative treatment according to image purpose and context.

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