Accessibility 101: What POUR Means and Why It Matters

POUR is the acronym for the four foundational principles of WCAG (Web Content Accessibility Guidelines). Every accessibility success criterion in WCAG falls under one of these four principles.

P — Perceivable

Users must be able to perceive the information being presented — it can’t be invisible to all of their senses.

What it covers

• Text alternatives for non-text content (alt text for images, labels for icons)
• Captions and transcripts for audio and video
• Content that can be presented in different ways without losing meaning (responsive layouts, reflow)
• Content that’s easy to see and hear (sufficient color contrast, no audio that auto-plays loudly)

Common failures

• Images with no alt text or with alt="image"
• Videos without captions
• Information conveyed only by color (e.g., red text = error, with no icon or label)
• Low color contrast (gray text on white)
• Text inside images instead of real text
• Content that breaks when zoomed to 200% or reflowed

Example success criteria

• 1.1.1 Non-text Content (A)
• 1.2.2 Captions (A)
• 1.4.3 Contrast Minimum (AA)
• 1.4.10 Reflow (AA)