Alternatives · Pa11y

Certvo vs Pa11y: which actually makes you compliant?

Pa11y is a free command-line accessibility tester, usually run in CI against a list of URLs. Certvo takes a different approach: we audit the underlying HTML and return code patches you can review and ship. Here is the honest comparison, including where Pa11y is the better choice.

Their pricing
Free and open source (LGPL 3.0).
Their approach
Node CLI that loads pages in headless Chrome and runs HTML CodeSniffer or axe-core rules.
Our approach
AI audit + code patches in your repo
Our pricing
Free public scan; from $29/mo for monitoring

What Pa11y does well

  • Genuinely free, scriptable, and easy to drop into a CI pipeline

  • Pa11y CI accepts a sitemap, so batch runs are straightforward

  • Choice of rule engines (HTML CodeSniffer or axe-core)

  • Configurable thresholds fail a build on regressions

Where Pa11y falls short

Every accessibility vendor has a target customer and a target solution. Pa11y's shape works for some teams and badly for others. The points below come up most often when buyers move off Pa11y and what they wish they had asked sooner.

  • Output is a violation list — no suggested markup, no explanation of the fix

  • HTML CodeSniffer, the default engine, is noisier than axe-core

  • You own the infrastructure: scheduling, storage, dashboards, alerting

  • No compliance artefacts (statement, VPAT) and no legal mapping

Why teams pick Certvo instead

  • Hosted crawl and schedule — nothing to run or keep alive

  • Every finding ships with the corrected code, not just the rule ID

  • Scan history and regression diffs between releases

  • Exportable reports plus VPAT and accessibility statement generators

Try a free public scan on the same URL you would test with Pa11y. Compare what each tool says is wrong and how each proposes to fix it.

When you should still pick the other tool

Bluntly: if the only thing you need is a visible widget on your site (e.g. as part of a settlement consent decree that names a specific overlay product), an overlay vendor is the path of least resistance. Certvo does not ship a widget. We give you patches; the widget is only a UI for the audit.

If you have an enterprise procurement process that already has a long-running contract with a competitor and the buying motion would take six months to switch, you can use Certvo alongside as the audit-and-fix tool while the widget keeps sitting on the page.

Frequently asked questions

Is Pa11y good enough on its own?

For a developer-owned pipeline with someone who knows WCAG well, yes — Pa11y is a solid gate that costs nothing. Where it runs out is remediation and evidence: it tells you rule X failed on selector Y, and the work of deciding what the correct markup is stays with you. If your bottleneck is fixing rather than finding, or if someone outside the engineering team needs a report, that gap is the thing to price.

Can I use Pa11y and Certvo together?

That is a sensible setup. Keep Pa11y or axe-core in CI as the free pre-merge gate, and use Certvo for the scheduled crawl of production, the generated fixes, and the compliance documents. The findings are compatible because both can run axe-core rules, so a Certvo finding will reproduce in your pipeline.

What does Pa11y cost to run at scale?

The licence is free; the running cost is engineering time. A production setup usually means a scheduled runner, somewhere to store results, a diffing step to spot regressions, and a dashboard for people who do not read JSON. Teams typically discover the maintenance is the expense, not the tool.

Other comparisons

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