Tenon vs Siteimprove 2026: API-First Tester vs Enterprise Platform
Updated June 2026 · 7 min read
The Core Distinction (Read This First)
Tenon and Siteimprove target completely different buyers. Tenon is a developer API — you call it programmatically to test URLs and get JSON results for CI/CD integration. Siteimprove is an enterprise governance platform covering accessibility, SEO, content quality, and analytics with a visual dashboard for non-technical stakeholders. The question isn't which is "better" — it's which one your team actually needs.
Tenon vs Siteimprove: Side-by-Side
| Factor | Tenon | Siteimprove |
|---|---|---|
| Type | API-first developer testing tool | Enterprise governance platform |
| Primary user | Developers, QA engineers | Content teams, web managers, compliance officers |
| Cost | Usage-based API pricing | $3,000–$100,000+/year (custom quote) |
| Coverage | Accessibility (WCAG) only | Accessibility + SEO + content quality + analytics |
| Interface | API (JSON responses) | Visual dashboard + reports |
| CI/CD integration? | Yes — designed for it | Limited — primarily scheduled crawls |
| Site crawling? | No — test URLs one at a time via API | Yes — automated scheduled site crawls |
| Human experts? | No | Consulting services available (extra cost) |
| Best for | Developer teams building accessible apps | Enterprises managing multiple sites + teams |
What Tenon Is (And What Developers Use It For)
Tenon (tenon.io) is an accessibility testing service built around an API. Rather than a browser extension or a dashboard you log into, Tenon is designed to be called programmatically — you send it a URL or a block of HTML, and it returns a JSON response with every detected WCAG violation.
A typical Tenon API response includes:
- Issue details: The specific WCAG 2.x success criterion violated, with level (A/AA/AAA)
- CSS selector: The exact element path in the DOM so developers can locate and fix it
- Certainty score: A confidence percentage indicating how certain Tenon is about the violation
- Priority: Severity ranking to help triage
- Code snippet: The relevant HTML snippet causing the issue
Tenon's design philosophy is "accessibility testing as a service" — the API can be called from anywhere: pre-commit hooks, GitHub Actions, Playwright tests, Jenkins pipelines, or custom dashboards. It's particularly valuable for teams that want to build accessibility into their deployment workflow at a code level.
Tenon Strengths
- API-first architecture: Easily integrated into any CI/CD pipeline or custom tooling
- Detailed technical output: CSS selectors, WCAG rule IDs, and certainty scores help developers act quickly
- Tests raw HTML: Can test HTML before it's deployed — useful for pre-publish validation
- Multiple WCAG versions: Supports WCAG 2.0, 2.1, and 2.2 rule sets
Tenon Limitations
- No visual dashboard: Non-technical stakeholders can't easily consume results without custom reporting built on top
- No site crawling: Tenon tests URLs you provide — it doesn't discover and crawl your whole site automatically
- Usage-based pricing: Costs can be hard to predict for high-volume testing; pricing not publicly transparent
- No remediation support: Tenon identifies violations; fixing them is entirely your team's responsibility
- Development-time focus: Not designed for ongoing live-site monitoring — better suited to pre-deploy testing
What Siteimprove Is (And Who It's Built For)
Siteimprove is a Danish enterprise SaaS company founded in 2003. Their platform started as a broken-link checker and has expanded into a comprehensive web governance tool covering:
- Accessibility: Automated WCAG scanning with a visual dashboard, issue prioritization, and compliance scoring
- SEO: Technical SEO auditing, keyword tracking, and on-page optimization
- Content Quality: Broken links, spelling errors, reading level, brand language compliance
- Analytics: Privacy-friendly web analytics alternative to Google Analytics
- Data Privacy: Cookie consent and privacy compliance scanning
Siteimprove's primary buyers are large enterprise organizations — universities, government agencies, and multi-national corporations — that need to manage web quality across many sites and teams. Their dashboard gives non-technical content editors actionable tasks, compliance managers portfolio-level views, and executives summary reports.
Where Siteimprove Excels
- Multi-site management: Manage accessibility compliance across dozens or hundreds of sites from one dashboard
- Non-technical users: Content editors can see and fix issues without understanding WCAG — the UI surfaces actionable tasks
- Automated crawling: Siteimprove crawls your entire site on a schedule, not just pages you manually test
- Compliance reporting: Generate WCAG compliance score reports for stakeholders and auditors
- Integrated governance: One tool for accessibility + SEO + content quality reduces tool sprawl for large teams
Siteimprove's Real Limitations
- Expensive: Pricing starts at $3,000–$5,000/year and scales quickly — significant overkill for organizations that only need accessibility monitoring
- Automated detection only: Siteimprove's accessibility scans catch the same ~30–40% of WCAG issues that other automated tools do — it doesn't replace manual audits
- No developer integration: No API for CI/CD — Siteimprove runs scheduled crawls, not commit-time checks
- Platform sprawl: Many accessibility-focused organizations only use 20–30% of Siteimprove's features, paying for capabilities they don't need
- Contract lock-in: Annual contracts, custom pricing, and enterprise sales cycles make it slow to evaluate and expensive to exit
Tenon vs Siteimprove: Which to Use When
Use Tenon when…
- You're a developer building CI/CD accessibility checks
- You want to test HTML programmatically before deploy
- You need an API that returns structured JSON violations
- You're building a custom accessibility dashboard
- Your team is technical and can act on raw WCAG findings
Use Siteimprove when…
- You're managing accessibility across 10+ sites
- Your users are non-technical content editors and compliance managers
- You need integrated SEO + accessibility + content quality
- You need executive-level compliance dashboards and reports
- Your organization has an enterprise budget and procurement process
For most mid-size organizations
Most organizations evaluating Tenon vs Siteimprove don't need either. Tenon is too technical (no crawling, no dashboard), and Siteimprove is too expensive (enterprise pricing for features you won't use). The better path: use axe DevTools (free) for developer auditing, RatedWithAI ($29/month) for continuous site-wide monitoring, and axe-core in CI/CD for regression prevention. This stack provides better WCAG coverage than either Tenon or Siteimprove alone, at a fraction of the cost.
Better Alternatives for Most Organizations
RatedWithAI — Continuous Site Monitoring
$29/month
Continuous axe-core scanning across your entire site with WCAG issue tracking and alerts. Fills the gap between Tenon (no crawling) and Siteimprove (too expensive) — automated site-wide monitoring at $29/month with no enterprise contract. No overlay widget, no setup complexity.
Start Free Scan →axe DevTools (Free) — Developer Auditing
Free browser extension
For developers, axe DevTools (free browser extension) plus axe-core in your test suite gives you better pre-deploy coverage than Tenon's API at no cost. The free extension provides the same rule engine as Tenon — the main Tenon advantage is programmatic API access, which axe-core itself already provides via npm.
Level Access or Deque — Enterprise Remediation
$10,000–$100,000+/year
For large enterprises that need both monitoring and managed remediation, Level Access and Deque both offer enterprise accessibility platforms with deeper WCAG coverage, human audit services, and legal defensibility documentation. More expensive than Siteimprove, but with significantly better accessibility depth — and you're not paying for SEO and content tools you don't need.
axe-core npm — API Alternative to Tenon
Free (open source)
If you're evaluating Tenon for its API, consider that axe-core is open source and free. You can run axe.run() in Playwright, Cypress, or a custom Node.js crawler and get the same structured violation data that Tenon returns — without API rate limits or usage billing. For most developer use cases, axe-core directly eliminates the need for Tenon entirely.
Continuous WCAG monitoring without the enterprise price tag
RatedWithAI scans your entire site for WCAG violations and alerts you to new issues. No overlay widget. No enterprise contract. $29/month.
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Frequently Asked Questions
Is Tenon still active in 2026?
Tenon (tenon.io) has had an uncertain status — the company has gone through changes in recent years and their public-facing marketing has been inconsistent. Before committing to Tenon for a production workflow, verify their current service status, SLA commitments, and pricing directly. The open-source alternative (axe-core via npm) is actively maintained by Deque and used by major enterprises including Microsoft, making it a more reliable dependency for CI/CD integration.
Does Siteimprove replace manual accessibility audits?
No. Siteimprove's automated scanning catches approximately 30–40% of WCAG violations — the same limitation that applies to all automated accessibility tools, including axe-core, WAVE, and Tenon. Issues requiring human judgment — keyboard navigation flows, screen reader announcements, complex widget interactions, focus management in dynamic applications — cannot be fully detected automatically. Siteimprove provides good automated coverage and useful reporting, but organizations pursuing genuine WCAG compliance still need periodic manual audits by accessibility specialists.
Can I use Tenon and Siteimprove together?
Technically yes, but it's redundant in most cases. Tenon is for developer pre-deploy testing; Siteimprove is for live-site monitoring and governance reporting. If you have both, you're paying for two tools that detect similar issues via similar automated methods. A more efficient stack would be axe-core in CI/CD (free, like Tenon but open source), RatedWithAI for live-site monitoring ($29/month, like Siteimprove but accessibility-focused and affordable), and Siteimprove only if you genuinely need its SEO and content quality modules.
What WCAG version does Tenon test against?
Tenon supports WCAG 2.0, 2.1, and 2.2, with the ability to specify which version to test against in the API request. This is useful for organizations with specific compliance targets — for example, US federal agencies required to meet Section 508 (which aligns with WCAG 2.1 AA), or organizations tracking conformance against WCAG 2.2 AA for newer requirements.
Is there a free version of Siteimprove?
Siteimprove offers a free browser extension called the Siteimprove Accessibility Checker, which provides basic WCAG violation checking for individual pages. It's useful for quick page-level audits but doesn't provide site crawling, compliance reporting, or the dashboard features of the paid platform. For organizations looking for free WCAG tooling, the Siteimprove browser extension, axe DevTools, and WAVE all provide similar page-level scanning capabilities.
How does Siteimprove compare to Deque for enterprise accessibility?
Siteimprove and Deque target similar enterprise buyers but with different emphases. Siteimprove is a broad governance platform where accessibility is one of several modules alongside SEO, content quality, and analytics. Deque is a dedicated accessibility company — everything they build is focused on WCAG compliance, including axe DevTools, axe-core, and their managed audit services. For organizations that only need accessibility, Deque provides more depth. For organizations that want a single platform for web governance broadly, Siteimprove covers more ground. Deque's pricing is also typically based on remediation scope rather than a flat platform fee, which may be more or less cost-effective depending on your needs.