Accessibility Checks Supported by the Siteimprove Accessibility for Designers

Answer

A check covers two groups. The first are formal WCAG criteria, filtered by the WCAG target you set in Settings. The second are best-practice recommendations that support readable, accessible design but are not formal conformance failures.

Overview

The Siteimprove Accessibility for Designers evaluates designs against a set of accessibility and usability checks to help identify issues early in the design process. Checks are divided into:

• Core WCAG checks
• Best-practice checks

Core WCAG Checks

Text contrast (AA)

WCAG: 1.4.3

What it checks: Text reaches 4.5:1 contrast (3:1 for large text).

Why it matters: Low-contrast text is hard to read for people with low vision or in bright conditions.

Text contrast (AAA)

WCAG: 1.4.6

What it checks: Enhanced contrast: 7:1 (4.5:1 for large text).

Why it matters: A stricter target for the highest level of readability.

UI / non-text contrast

WCAG: 1.4.11

What it checks: Icons, controls, and borders reach 3:1.

Why it matters: Interface elements must be distinguishable, not just text.

Text over image

WCAG: 1.4.3

What it checks: Text sits on an image or gradient, so contrast cannot be measured automatically.

Why it matters: Flagged for review so text does not become unreadable over busy backgrounds.

Touch target size (AA)

WCAG: 2.5.8

What it checks: Interactive targets are at least 24×24 px.

Why it matters: Small targets are hard to tap for people with motor impairments.

Touch target size (AAA)

WCAG: 2.5.5

What it checks: Interactive targets reach the recommended 44×44 px.

Why it matters: Larger targets are easier and more comfortable to activate.

Link by color alone

WCAG: 1.4.1

What it checks: A link may be distinguished only by color.

Why it matters: Users who cannot perceive color need another cue, such as an underline.

Best-Practice Checks

Text too small

What it checks : Text under 12 px.

Why it matters: Very small text is difficult to read for many users.

Truncated / clipped text

What it checks : Content hidden by an ellipsis or a fixed box.

Why it matters: Hidden content cannot be read by anyone.

Tight line height

What it checks : Paragraphs with less than roughly 1.5× line spacing.

Why it matters: Cramped lines are harder to track, especially with dyslexia.

Tight letter spacing

What it checks : Paragraph text with negative tracking.

Why it matters: Squeezed characters reduce legibility.

All-caps paragraph

What it checks: Blocks of all-uppercase text.

Why it matters: All-caps passages are slower to read.

Justified paragraph

What it checks : Justified body text.

Why it matters: Uneven word spacing creates distracting “rivers” of white space.

All-italics paragraph

What it checks: Long passages set entirely in italics.

Why it matters: Extended italics are tiring to read.

Why It Matters

The Siteimprove Accessibility for Designers combines formal WCAG validation with best-practice recommendations to help teams identify accessibility issues and improve design usability before development begins.

Key Takeaways

• Checks are divided into Core WCAG checks and Best-Practice checks.
• Core WCAG checks map directly to specific WCAG success criteria.
• Best-practice checks provide advisory guidance that supports readable and accessible design.
• Results help designers identify and address accessibility issues before handoff to development.