How to Build a Website Accessibility Checker Tool: The Complete 2026 Guide
A website accessibility checker scans sites for WCAG compliance issues and generates prioritized fix lists — helping businesses avoid ADA lawsuits that average $15,000 in settlements. This idea scores 81/100, with the strongest regulatory tailwind of any micro-SaaS opportunity.
In March 2024, a three-location pizza restaurant in Ohio received a demand letter: their website violated the ADA. Images lacked alt text, forms had no labels, and the menu PDF was unreadable by screen readers. Settlement demand: $15,000. The owner had never heard of WCAG. Their web developer had used a template with zero accessibility consideration.
This isn't rare. 4,605 ADA web accessibility lawsuits were filed in 2023 — up 300% from 2018. And 2025 is worse: lawsuits rose 37% in Q1 alone. The targets? Mostly small businesses. 77% of lawsuits target companies with under $25 million in revenue because they're easier wins for serial plaintiff law firms.
The opportunity is clear: businesses need affordable accessibility protection. AccessiBe raised $58M selling a $49/mo "widget" solution — but overlay widgets are increasingly getting sued themselves. 25% of 2024 lawsuits explicitly cited accessibility widgets as barriers. Real compliance requires real code fixes, not JavaScript band-aids.
Why Accessibility Checkers Are Printing Money Right Now
The regulatory landscape has never been more favorable for accessibility tools.
The Market Signals
| Signal | Evidence |
|---|---|
| Market proof | AccessiBe at $3M+ MRR, Deque at $5M+ MRR, SiteImprove major player |
| Problem urgency | ADA lawsuits averaging $15K — fear-driven purchase decision |
| Target audience | 30M+ small business websites in US alone |
| Pricing tolerance | $15-99/mo validated; $15/mo is trivial vs $15K lawsuit risk |
| Regulatory tailwind | EU Accessibility Act (June 2025), DOJ website recognition, state laws |
The Three Forces Converging
1. Lawsuit explosion continues
- 4,605 lawsuits in 2023 (record)
- 23% increase in Q1 2025 vs Q1 2024
- Serial plaintiff law firms using automated scanners to find violations at scale
2. Overlay backlash creates demand for real tools
- National Federation of the Blind testified against overlay widgets
- 25% of 2024 lawsuits cited widgets as barriers, not solutions
- Businesses burned by AccessiBe looking for actual fixes
3. Global regulatory expansion
- EU Accessibility Act effective June 2025
- DOJ formally recognized websites under ADA Title III
- Canada, Australia expanding requirements
- 1.3 billion people globally with disabilities = 15% of potential customers excluded
How Accessibility Checkers Actually Work
Understanding the mechanics reveals why this is buildable by a solo developer.
The Problem It Solves
A local restaurant owner gets a demand letter. Their options:
- Pay the settlement — $15,000+ and likely repeat violations
- Hire an agency — $5,000-20,000 for a full audit
- Use enterprise tools — SiteImprove at $400+/mo, Deque at $5K+/yr
- Your tool — $15/mo for automated scanning + fix instructions
Option 4 is the only accessible path for 90% of small businesses.
What WCAG Actually Tests
| Category | Examples | Why It Matters |
|---|---|---|
| Perceivable | Alt text, captions, color contrast | Users can access content |
| Operable | Keyboard navigation, no seizure triggers | Users can interact |
| Understandable | Clear labels, consistent navigation | Users comprehend it |
| Robust | Valid HTML, ARIA labels | Assistive tech works |
WCAG 2.1 AA is the legal standard for ADA compliance. There are 50+ specific success criteria, but automated tools can catch 30-40% of issues — the low-hanging fruit that triggers most lawsuits.
The Technical Flow
- User enters URL — Dashboard or free audit tool
- Crawler fetches pages — Puppeteer/Playwright renders JavaScript
- axe-core runs tests — Industry-standard rule engine
- Issues categorized — Critical, serious, moderate, minor
- Fix suggestions generated — Plain-English instructions with code snippets
- Report delivered — Dashboard + PDF for compliance documentation
- Monitoring schedules — Weekly/monthly rescans with diff alerts
The Competitive Landscape
Understanding competitors reveals your positioning opportunity:
Current Players
| Tool | Pricing | Approach | Gap |
|---|---|---|---|
| AccessiBe | $49/mo | Overlay widget | Getting sued; doesn't fix code |
| Deque (axe) | $5,000+/yr | Gold standard scanner | Enterprise-only pricing |
| SiteImprove | $400+/mo | Full platform | Too expensive for SMBs |
| WAVE | Free | Single-page scanner | No monitoring, no fixes, no crawling |
| AccessibilityChecker.org | $99+/mo | Automated scanner | Still expensive for small sites |
| Equalize Digital | $99+/yr | WordPress plugin | Platform-specific |
Where's the Gap?
The $15-39/mo tier is completely underserved.
- AccessiBe is at $49/mo but its overlay approach is legally questionable
- Everything else is either free (and limited) or $99+/mo
- Small businesses need "accessibility insurance" they can actually afford
Your positioning: "Real WCAG scanning at small business prices. Not an overlay — actual fixes."
The Technical Stack
Good news: the hardest part (WCAG rule engine) is open source.
Recommended Architecture
Frontend Layer: Next.js dashboard for results, reports, and user management
Crawler Layer: Puppeteer renders JavaScript pages, queues pages for scanning
Scanner Layer: axe-core runs 50+ WCAG checks per page
Backend Layer: Node.js API, Supabase (PostgreSQL), BullMQ job queue, OpenAI for plain-English fix explanations
Infrastructure: Vercel (frontend), AWS Lambda (compute-heavy scanning), Stripe (payments)
Why This Stack?
| Component | Choice | Reasoning |
|---|---|---|
| Scanner | axe-core | Industry standard, 80+ rules, actively maintained |
| Crawler | Puppeteer/Playwright | Renders JavaScript, captures full DOM |
| Frontend | Next.js + Tailwind | Fast development, great SEO for free tool |
| Database | Supabase (PostgreSQL) | Quick setup, row-level security |
| Queue | BullMQ or Inngest | Handle scanning jobs without blocking |
| AI assist | OpenAI | Turn technical violations into plain-English fixes |
| Payments | Stripe | Industry standard, usage-based billing |
The axe-core Advantage
axe-core is open source and handles the hard work. Import AxePuppeteer from @axe-core/puppeteer, launch a browser with Puppeteer, navigate to the URL, then call AxePuppeteer with WCAG tags (wcag2a, wcag2aa, wcag21aa) and analyze(). The results object gives you:
- Violations — Definite failures
- Incomplete — Needs manual review
- Passes — Confirmed compliant
- Inapplicable — Not relevant to page
The Revenue Model
Fear-driven purchases have high conversion rates. Position this as "insurance."
Value Ladder
| Tier | Price | Features | Target |
|---|---|---|---|
| Free Audit | $0 | Single-page scan, top 5 issues | Lead generation |
| Protect | $15/mo | 100 pages, monthly scans, fix guide | Small business |
| Agency | $39/mo | Unlimited pages, 5 sites, white-label | Web agencies |
| Enterprise | Custom | API, SSO, dedicated support | Large companies |
Why This Pricing Works
$15/mo = Lawsuit Insurance
The math is impossible to argue with:
- Average lawsuit settlement: $15,000
- Annual cost of protection: $180
- ROI of avoiding one lawsuit: 83x
Revenue Projections
| Milestone | Customers | MRR | Timeline |
|---|---|---|---|
| Launch | 50 | $750 | Month 1-2 |
| Traction | 200 | $3,000 | Month 3-4 |
| Growth | 500 | $7,500 | Month 6 |
| Scale | 1,500 | $20,000 | Month 12 |
Conservative estimates. AccessiBe proves 200K+ websites will pay for this.
Go-to-Market Strategy
The playbook for acquiring customers in this space:
Phase 1: Free Tool as Lead Magnet (Weeks 1-4)
Build a free single-page scanner. This is your acquisition engine.
- "Website Accessibility Checker" gets 15K+ searches/month
- Instant results, no signup required
- Show 5 issues free, full report requires email
- "Your site has 47 accessibility issues. Fix them before you get sued."
Phase 2: Content Marketing (Ongoing)
Fear + education content performs extremely well here.
Target keywords:
- "ADA website compliance" (8K searches/mo)
- "WCAG 2.1 checklist" (5K searches/mo)
- "ADA lawsuit small business" (3K searches/mo)
- "website accessibility requirements" (12K searches/mo)
Content ideas:
- "ADA Website Lawsuits: How to Protect Your Business for $15/mo"
- "The WCAG 2.1 Checklist Every Small Business Owner Needs"
- "Accessibility Overlay Widgets: Why They're Getting Sued"
Phase 3: Partnership & Outreach (Month 2+)
Web agencies are your distribution channel.
- Offer white-label reports they can brand
- Partner pricing (pay per client site scanned)
- They have the client relationships, you have the tool
Target high-risk industries directly:
- Restaurants (highest lawsuit rate)
- Retail / e-commerce
- Healthcare
- Real estate
Phase 4: Product Hunt & Community (Month 3)
The accessibility community is active and supportive of real tools.
- Product Hunt: social good angle boosts upvotes
- r/accessibility (40K members)
- r/webdev (2.3M members)
- Web accessibility Twitter amplifies real tools
Build Timeline
A realistic timeline for a solo developer:
| Week | Focus | Deliverable |
|---|---|---|
| 1 | Core scanner | axe-core + Puppeteer pipeline working |
| 2 | Multi-page crawl | Queue-based page discovery + scanning |
| 3 | Dashboard | Results UI, issue details, fix suggestions |
| 4 | Free tool | Single-page scanner with email capture |
| 5 | Payments | Stripe integration, subscription tiers |
| 6 | Polish | PDF reports, onboarding, monitoring |
MVP in 4-5 weeks is realistic. The scanner is the easy part (thanks to axe-core). The product is in the UX — making technical violations understandable to non-developers.
Risks and Mitigations
Every opportunity has risks. Here's how to handle them:
| Risk | Mitigation |
|---|---|
| Automated scanning catches only 30-40% of issues | Be transparent: "automated scan + human audit recommendation." Upsell manual reviews. |
| AccessiBe could pivot to real scanning | Move fast. They're invested in the widget approach. |
| False positives erode trust | Use axe-core's conservative ruleset. Let users mark false positives. |
| Commoditization | Differentiate on UX, fix quality, and agency partnerships. |
Frequently Asked Questions
What is WCAG and why does it matter for businesses?
WCAG (Web Content Accessibility Guidelines) is the international standard for web accessibility, developed by the W3C. WCAG 2.1 Level AA is the legal benchmark for ADA compliance in the US. Businesses need WCAG compliance to avoid lawsuits — over 4,600 ADA web accessibility lawsuits were filed in 2023, and settlements average $15,000.
How much does an accessibility audit cost?
Professional manual audits cost $1,500-20,000 depending on site complexity. Enterprise automated tools like SiteImprove start at $400+/month. The gap in the market is automated scanning at $15-39/month for small businesses — affordable "accessibility insurance" that catches the most common violations.
What's the difference between accessibility checkers and overlay widgets?
Accessibility checkers scan your website and tell you what to fix in your actual code. Overlay widgets (like AccessiBe) inject JavaScript to patch accessibility issues in the browser. The problem: overlays often don't work, the National Federation of the Blind opposes them, and 25% of 2024 ADA lawsuits explicitly cited overlay widgets as barriers.
Can automated tools make my website fully ADA compliant?
Automated scanners catch 30-40% of WCAG issues — the programmatic checks like missing alt text, color contrast failures, and form label problems. Full compliance requires manual testing with screen readers and keyboard navigation. However, automated scanning catches the issues that trigger most lawsuits and provides ongoing monitoring.
How many pages should an accessibility checker scan?
It depends on site size, but most small business sites have 10-100 pages. A good accessibility checker should crawl your entire site automatically, prioritize issues by severity, and monitor for regressions. Pricing tiers typically scale by page count: 100 pages for small sites, 500+ for larger sites.
The Bottom Line
Website accessibility is a $700M market with the strongest regulatory tailwind in tech. Lawsuits are up 300% since 2018 and climbing. Overlay widgets are getting sued. Enterprise tools are too expensive.
The gap at $15-39/month is massive and underserved.
You're not just building a scanner — you're selling "lawsuit insurance" to 30 million small businesses. At $15/month, the ROI story writes itself.
Build time: 4-5 weeks to MVP
Revenue potential: $20-50K MRR
Execution difficulty: 6/10 (axe-core does the heavy lifting)
View full research and scoring →
Start Building Now
Ready to build? Here's your AI-assisted prompt to get started:
Claude Code / Cursor Prompt
Build a website accessibility checker SaaS with: Puppeteer/Playwright for page rendering, axe-core for WCAG 2.1 AA testing, multi-page crawling with BullMQ, results stored in Supabase PostgreSQL. Dashboard with Next.js + Tailwind showing site list, issue severity, fix suggestions, and PDF reports. Free tool: single URL scan, top 5 issues free, full report requires email. Monetization: Stripe with Free, Protect ($15/mo for 100 pages), Agency ($39/mo unlimited). Use OpenAI to convert technical violations into plain-English fixes.
This is one of the highest-conviction opportunities in our database. The fear of a $15,000 lawsuit makes $15/month an instant yes.