Do not disable pinch zoom
SkillDocs & knowledgeviewport-zoom is a skill that checks the viewport meta tag in HTML documents for settings that disable pinch-to-zoom, such as user-scalable=no or maximum-scale values below 2. It explains why disabling zoom blocks low-vision users, cites the relevant WCAG success criterion, and shows the correct tag to use instead.
Available today. Use it from your connected AI after setup.
No other account needed.
Have the HTML document you want to review available to the agent.
Then ask your AI: use the Do not disable pinch zoom skill
What your AI can do with it
- Detects user-scalable=no and user-scalable=0 in the viewport meta content attribute
- Flags maximum-scale=1 or any maximum-scale value below 2
- Checks CSS for touch-action: none and user-zoom: fixed that limit zoom
- Recommends the correct tag: <meta name='viewport' content='width=device-width, initial-sca
- Suggests form input font-size: 1rem (16px) to prevent iOS auto-zoom on input focus
- References WCAG 2.1 SC 1.4.4 (Resize Text, Level AA) requirements
Getting started
- Have the HTML document you want to review available to the agent.
- Add the viewport-zoom skill to the agent's available skills.
- Ask the agent to check the document's viewport meta tag for zoom restrictions.
- Apply the recommended fix by removing user-scalable=no and maximum-scale=1 from the tag.
What this skill tells your AI
The instructions your AI receives, as published by thedaviddias/front-end-checklist in skills/viewport-zoom/SKILL.md and read by ahel’s review.
Pinch-to-zoom is an essential accessibility feature for low-vision users who cannot read text at the page's default size. When zoom is disabled, these users cannot enlarge text or images, making the page completely inaccessible without external magnification software. Low-vision users who rely on browser zoom are entirely blocked. Additionally, all users benefit from being able to zoom in on small text, fine-print, or complex images. Disabling zoom is one of the most harmful and easily preventable accessibility failures.
Quick Reference
- Never use
user-scalable=nooruser-scalable=0in the viewport meta tag - Never set
maximum-scale=1(or any value below 5) in the viewport meta tag - Both prevent pinch-to-zoom, violating WCAG 2.1 SC 1.4.4 (Resize Text, Level AA)
- The correct viewport meta tag is:
<meta name='viewport' content='width=device-width, initial-scale=1'> - Note: iOS 10+ ignores
user-scalable=noin Safari, but other browsers and older iOS do not
Check
Find the <meta name='viewport'> element in the HTML <head>. Check its content attribute for: (1) user-scalable=no — disables all zoom; (2) user-scalable=0 — same effect; (3) maximum-scale=1 or maximum-scale=1.0 — limits zoom to the initial scale; (4) any maximum-scale value below 2 — significantly limits zoom range. Flag any of these. Also check CSS for touch-action: none or user-zoom: fixed (CSS Device Adaptation, rarely used) that may limit zoom.
Fix
Remove user-scalable=no and maximum-scale=1 from the viewport meta tag. The correct viewport meta tag for a responsive site is: <meta name='viewport' content='width=device-width, initial-scale=1'>. If maximum-scale was set for a specific reason (e.g., to prevent unintended zoom on input focus on iOS), the correct fix is to set form input font-size: 1rem (16px) instead — iOS Safari only auto-zooms on input focus when font-size is below 16px.
Explain
WCAG 2.1 SC 1.4.4 (Resize Text, Level AA) requires that text can be resized up to 200% without loss of content or functionality, except for captions and images of text. On mobile devices, pinch-to-zoom and the browser's built-in text size settings are the primary mechanisms for resizing text. Setting user-scalable=no or maximum-scale=1 in the viewport meta tag disables pinch-to-zoom entirely (or limits it to 1x), preventing low-vision users from enlarging content. This is a direct violation of SC 1.4.4. While iOS 10+ Safari ignores these settings, Android browsers, Chrome for iOS, and older iOS versions do not — so the setting must be removed regardless.
Code Review
Review stylesheets, component styles, and responsive states related to Do not disable pinch zoom. Flag exact selectors, declarations, or breakpoints that violate the rule in the rendered UI.
For full implementation details, code examples, and framework-specific guidance,
see references/rule.md.
Rule page: https://frontendchecklist.io/en/rules/accessibility/viewport-zoom
Signals
- GitHub stars
- 74k
- Forks
- 7k
- Last commit
- Aug 2026
Questions
- Why is disabling pinch zoom an accessibility problem?
- Low-vision users who cannot read text at the default size rely on pinch-to-zoom to enlarge content. When zoom is disabled, they cannot read the page without external magnification software, and all users lose the ability to zoom in on small text or fine print.
- What viewport meta tag should I use instead?
- The correct tag for a responsive site is <meta name='viewport' content='width=device-width, initial-scale=1'>. Remove user-scalable=no and maximum-scale=1 from the content attribute.
Advanced
- Item type
- skill
- Key
viewport-zoom- Source
- github.com/thedaviddias/front-end-checklist