axe-core
axe-core is the open-source accessibility testing engine maintained by Deque Systems that powers most major automated accessibility scanners, including AccessComply's.
Detailed explanation
axe-core is a JavaScript library that runs against a rendered DOM and returns a set of WCAG-mapped violations. It is the default engine inside Google Lighthouse, Microsoft Accessibility Insights, Cypress-axe, Playwright-axe, the React Testing Library, and most commercial accessibility platforms.
axe-core has zero false positives by design — Deque's rule team rejects rules that cannot be tested deterministically. This makes it conservative: axe-core finds roughly 30-40% of WCAG issues automatically; the rest require manual or assistive-technology testing. axe-core is licensed Mozilla Public License 2.0 and is free to use commercially.
How this applies to Shopify stores
AccessComply runs axe-core against every page of the storefront via headless Chromium. We then layer Shopify-specific rules (theme version, app conflicts, Liquid antipatterns) and visual diffing on top of axe so merchants get a complete picture, not just the automated 30%.
What merchants should check next
Treat this term as a practical audit prompt, not just a definition. Check the storefront pages where the concept shows up in real customer journeys: product discovery, add-to-cart, cart drawer, checkout handoff, account login, and support contact flows. If the issue affects code, verify the rendered HTML and computed browser output after the theme change. If it affects copy or media, keep the merchant-facing wording accurate and easy to maintain.
Primary source: github.com