Comparison

Pa11y vs Siteimprove

No leader: the top candidate Pa11y has only 0.30 confidence (low), below the 0.35 needed to declare a winner. The attribute-by-attribute breakdown below, with a source and date on every value, is the honest way to compare them.

Machine formatsJSONMarkdownGraphQLor send Accept: application/json
Pa11y45
Siteimprove13
Score
Vioscale score
Pa11y45 / 100low · 30%
Siteimprove13 / 100low · 15%
Pricing
Free tier
Pa11y
Siteimprove
Model
Siteimprovequote
Price level
Pa11yfree
Siteimproveunknown
Transparent
Pa11y
Siteimprove
Integrations
Count
Pa11y
Siteimprove25
Adoption
Dependent repos
Pa11y1,668
Siteimprove
Github stars
Pa11y4,490
Siteimprove
Activity
Commits last 30d
Pa11y3
Siteimprove
Release
Cadence days
Pa11y131
Siteimprove
History
Pa11y6 items
Siteimprove
License
Spdx
Siteimprove
Language
Primary
Siteimprove
Market
Availability
Pa11y

Capabilities

Feature-by-feature on the axes that matter for accessibility testing. “-” means undocumented, not absent.

Capabilities
Scan method
Pa11yAutomated rules engine
Siteimprove-
Wcag level
Pa11y-
Siteimprove-
Ci cd integration
Pa11y
Siteimprove-
Browser extension
Pa11y-
Siteimprove-
Design stage plugin
Pa11y-
Siteimprove-
CMS plugins
Pa11y-
Siteimprove-
Continuous monitoring
Pa11y
Siteimprove-
Vpat acr generation
Pa11y-
Siteimprove-
Manual audit service
Pa11y-
Siteimprove-
Overlay widget
Pa11y-
Siteimprove-
Document PDF testing
Pa11y-
Siteimprove-
Open source
Pa11y
Siteimprove-

What each one is

The product in its own terms, so the numbers below have context.

Pa11y

A suite of free and open-source tools for identifying and tracking accessibility issues on websites. Provides both automated testing via a web dashboard and command-line utilities for developers.

Independently observed

Siteimprove

Siteimprove is a SaaS platform that helps teams ensure digital content meets accessibility standards, performs well in search engines, and maintains consistent quality. AI agents provide real-time guidance and automation throughout content creation and website management workflows.

Independently observed

Pricing

List pricing as published by each vendor, with the date we read it. Always verify at the source before you buy.

Pa11y

Open sourceFree tier

Free and open source

as of verify ↗

Siteimprove

Quote-based

Custom enterprise pricing — contact sales for detailed quote

as of verify ↗

Platform & deployment

Where each product runs and how it can be hosted. A dash means undocumented, not unsupported.

Platforms
Web
Pa11y
Siteimprove
Linux
Pa11y
Siteimprove
CLI
Pa11y
Siteimprove
Deployment
Cloud / SaaS
Pa11y
Siteimprove
Self-hosted
Pa11y
Siteimprove

Integrations

What each product connects to. Counts come from the vendor's own integration directory where one exists.

Pa11y

Not documented yet.

Siteimprove

25 total
  • Adobe Experience Manager
  • Optimizely
  • WordPress
  • Drupal
  • TYPO3
  • Sitecore
  • Google Analytics
  • Kentico Xperience
  • Umbraco
  • Magnolia CMS
  • Jahia
  • CoreMedia
  • Tridion
  • Cascade
  • FirstSpirit
  • Enonic
  • Plone
  • SiteVision
  • Sitefinity
  • govAccess
  • Sitebox
  • Percussion
  • IPROX-CMS
  • i:Create
  • +1 more
Independently observed

Comparison generated from independently-sourced facts. Every value links to its source and retrieval date. See the method.