WCAG 2.0 vs 2.1 (2026) | What Changed and Which One You Need

Last updated: 2026-07-10

WCAG 2.0 and WCAG 2.1 are two versions of the same standard: the Web Content Accessibility Guidelines published by the W3C. WCAG 2.0 arrived in December 2008 with 61 success criteria, and for a decade it was the reference point that laws and lawsuits pointed to. WCAG 2.1 was published in June 2018 and added 17 brand-new success criteria on top of everything in 2.0, for a total of 78. Crucially, 2.1 is fully backward compatible — every requirement in 2.0 is still there, unchanged, so if your site meets WCAG 2.1 you automatically meet 2.0 as well. The reason 2.1 exists is that the web changed enormously between 2008 and 2018: smartphones, touchscreens, and a much better understanding of low-vision and cognitive needs were barely addressed by the original standard. The new criteria in 2.1 fill those gaps, covering mobile orientation, pinch-to-zoom reflow, touch target behavior, text spacing, and more. This comparison explains exactly what changed, why it matters for a small business site, and — most importantly — which version the current laws actually require you to meet.

At a Glance

Feature WCAG 2.0 WCAG 2.1
Published December 2008 June 2018
Total success criteria 61 78 (the 61 from 2.0 plus 17 new)
New Level A/AA criteria added None (this is the baseline) 12 new A/AA criteria (plus 5 new AAA)
Mobile and touch coverage Minimal — predates smartphones Yes — orientation, pointer gestures, pointer cancellation, motion actuation
Low-vision coverage Basic text contrast only Adds Reflow, Non-text Contrast, Text Spacing, Content on Hover or Focus
Backward compatible N/A Yes — meeting 2.1 also satisfies 2.0
Referenced by which laws US Section 508 refresh (WCAG 2.0 AA) EU EN 301 549 / EAA and US DOJ ADA Title II rule (WCAG 2.1 AA)

WCAG 2.0

Type: W3C Recommendation published December 2008 — 4 principles, 12 guidelines, 61 success criteria across Levels A, AA, and AAA Pricing: Free — WCAG is an open, published standard with no license fee. Best for: Understanding the historical baseline, and for US federal Section 508 work, which still formally references WCAG 2.0 Level AA.

Pros

  • The foundation everything else builds on — its 61 criteria still form the core of every later version
  • Referenced by the older text of the US Section 508 refresh, which incorporates WCAG 2.0 Level A and AA
  • Extremely well documented after more than 15 years, with mature 'Understanding' and 'Techniques' support pages
  • Meeting 2.0 alone already resolves the large majority of accessibility barriers a typical site has

Cons

  • Written before the smartphone era, so it barely addresses touchscreens, small viewports, or device orientation
  • No dedicated requirements for pinch-to-zoom reflow, minimum non-text contrast, or text spacing — real barriers for low-vision users
  • Increasingly outdated as a legal benchmark: newer laws and the EU standard now point to 2.1 or later, not 2.0
  • A site that only targets 2.0 can still fail on mobile in ways modern users and courts notice

WCAG 2.1

Type: W3C Recommendation published June 2018 — everything in 2.0 plus 17 new success criteria, for 78 total across Levels A, AA, and AAA Pricing: Free — an open, published standard with no license fee. Best for: Almost everyone building or maintaining a website today — 2.1 Level AA is the practical, legally referenced target for most organizations worldwide.

Pros

  • Adds mobile and touch requirements: pointer gestures, pointer cancellation, motion actuation, and device orientation (Success Criteria 2.5.1-2.5.4 and 1.3.4)
  • Adds low-vision requirements including Reflow (1.4.10), Non-text Contrast (1.4.11), Text Spacing (1.4.12), and Content on Hover or Focus (1.4.13)
  • Fully backward compatible: conforming to 2.1 means you also conform to 2.0, so there is no trade-off in adopting it
  • The version most modern laws now reference, including the EU's EN 301 549 and the US DOJ's ADA Title II web rule, both at Level AA

Cons

  • Slightly more work than 2.0 because of the 12 additional Level A/AA criteria you must meet
  • Some of the new criteria (like Reflow and Text Spacing) require testing at 400% zoom and with custom spacing, which teams often forget
  • Not the newest version — WCAG 2.2 (published 2023) adds nine more criteria, so 2.1 is a floor rather than the ceiling
  • Automated tools still cannot check most of the new human-judgment criteria, so manual testing is required

Our Verdict

For any website being built or maintained today, target WCAG 2.1 Level AA, not 2.0. The two versions are not really rivals — 2.1 is simply 2.0 with 17 extra criteria bolted on, and because it is fully backward compatible there is no downside to adopting it. The practical case for 2.1 is that the internet is now used mostly on phones and by an aging population with more low-vision needs, and the 12 new Level A/AA criteria address exactly those gaps: content that reflows without horizontal scrolling at 400% zoom, buttons and form fields that have enough contrast, layouts that survive increased text spacing, and touch interactions that do not trap users. Just as important, 2.1 Level AA is the version the current laws point to — the EU's EN 301 549 (which underpins the European Accessibility Act) and the US Department of Justice's 2024 ADA Title II web rule both reference WCAG 2.1 AA. The only reason to think in terms of 2.0 today is US federal Section 508 work, which still formally cites 2.0 Level AA. Our recommendation: meet 2.1 Level AA as your baseline and keep an eye on 2.2, which adds nine further criteria and is where the standard is heading next.

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