Siteimprove vs axe-core

Quote on request

Free and open source

Enterprise annual contracts priced by pages crawled and modules.

Free and open source. You pay in engineering time and CI minutes.

Free browser extension for single-page checks.

Everything, self-hosted

Widely used

Siteimprove · since 2003

Category standard

Deque Systems · since 2015

• Scans entire large sites and assigns findings to content owners, not just developers.
• Combines accessibility with SEO and content quality in one governance view.
• Reporting suited to demonstrating compliance progress to executives and regulators.

• Effectively zero false positives, which is why it became the industry default.
• Integrates into any existing test suite in a few lines.
• Free, actively maintained, and aligned with WCAG updates.

• Expensive and aimed at organisations with a governance function.
• Weak fit for application testing as opposed to content sites.
• Limited shift-left developer tooling compared to Deque.

• Automated rules detect roughly a third of WCAG issues — the rest need human testing.
• A library, not a workflow: no dashboards, tracking or reporting.
• Only evaluates the DOM state it is given, so dynamic states need explicit test coverage.

Universities, government and large content organisations with legal accessibility obligations.

Any team that wants accessibility checks inside their existing automated tests.