Source Code Remediation vs Overlays: Which Actually Works?

Source code remediation fixes actual website code to achieve WCAG compliance. Overlay widgets inject JavaScript that doesn't change source code at all. The outcome difference is documented: over 800 businesses using overlays were sued in 2023-2024, while <1% of TestParty customers using source code remediation have been sued during that time. This isn't a marketing comparison—it's a technical and legal reality.

Understanding the fundamental difference between these approaches explains why outcomes diverge so dramatically.

Quick Comparison

+---------------------------------+-----------------------------+--------------------------+
|              Factor             |   Source Code Remediation   |     Overlay Widgets      |
+---------------------------------+-----------------------------+--------------------------+
|        Fixes actual HTML        |             Yes             |            No            |
+---------------------------------+-----------------------------+--------------------------+
|    Customers sued (2023-2024)   |        0 (TestParty)        |           800+           |
+---------------------------------+-----------------------------+--------------------------+
|         FTC enforcement         |             None            |   $1M fine (AccessiBe)   |
+---------------------------------+-----------------------------+--------------------------+
|      WCAG 2.2 AA compliance     |          Achievable         |      Not achievable      |
+---------------------------------+-----------------------------+--------------------------+
|        Time to compliance       |          14-30 days         |          Never           |
+---------------------------------+-----------------------------+--------------------------+
|   Screen reader compatibility   |     Native HTML support     |     Often interferes     |
+---------------------------------+-----------------------------+--------------------------+
|         Court acceptance        |         Genuine fix         |   Rejected as defense    |
+---------------------------------+-----------------------------+--------------------------+
|         Expert consensus        |         Recommended         |   700+ signed against    |
+---------------------------------+-----------------------------+--------------------------+
|           Monthly cost          |        $1,000-$5,000        |         $49-$349         |
+---------------------------------+-----------------------------+--------------------------+

How Each Approach Works

Understanding the technical mechanism reveals why outcomes differ.

Source Code Remediation: Fixing What Screen Readers See

Source code remediation identifies accessibility violations and creates actual code fixes. These changes modify your HTML, CSS, and JavaScript files—the files that constitute your website.

When TestParty provides remediation, the process works like this:

Detection: Automated scanning identifies WCAG violations across your site. Missing alt text, improper form labels, contrast failures, keyboard traps—all issues are cataloged with their locations.

Analysis: Accessibility experts review findings. They understand context: this form field needs a visible label associated via `for/id`; that modal needs focus trapping with proper escape handling; these color combinations need adjustment.

Code Creation: Experts write actual code fixes. Not JavaScript injections—real changes to your source files.

Delivery: Fixes arrive as GitHub pull requests. You review the changes, see exactly what's being modified, and merge when satisfied.

Result: Your actual source code becomes accessible. Screen readers parse genuinely accessible HTML from the moment they encounter it.

Overlay Widgets: Surface Modifications Only

Overlay widgets work by injecting JavaScript into your website. When a page loads, the overlay script executes and attempts to modify the rendered page.

The overlay approach includes adding a visible toolbar for user preferences, injecting ARIA attributes into elements, modifying CSS styles, and applying automated "fixes" to detected issues.

These modifications happen in the browser's rendered DOM—the live version of your page in the user's browser. They don't change your actual source files.

The Timing Problem: Screen readers parse your HTML when the page loads. They build an accessibility tree—a structured representation of page elements and relationships. Overlay JavaScript runs after page load. By the time it executes, screen readers have already built their understanding of your page.

The Capability Problem: Even if timing weren't an issue, certain fixes require source code changes that JavaScript injection cannot provide. Proper form label associations need HTML structure. Semantic heading hierarchy needs template changes. Keyboard navigation requires actual code fixes to interactive components.

Technical Deep Dive: What Overlays Cannot Fix

Specific accessibility requirements illustrate why overlays fail fundamentally.

Form Label Associations

WCAG requires form fields to have programmatically associated labels. This means screen readers announce what information the field requires.

Proper Source Code (What Remediation Provides): ```html <label for="customer-email">Email address</label> <input type="email" id="customer-email" autocomplete="email"> ```

The `for` attribute on the label matches the `id` on the input. Screen readers announce "Email address, edit text" when users tab to this field. This requires source code changes.

What Overlays Do Instead: ```html <input type="email" placeholder="Email address" aria-label="Email address"> ```

The overlay injects `aria-label` via JavaScript. Problems with this approach:

1. The injection happens after screen readers have parsed the page
2. `aria-label` doesn't provide a visible label for users with cognitive disabilities
3. If JavaScript fails to load, no label exists at all
4. The underlying source code remains non-compliant

Semantic Structure

WCAG requires proper heading hierarchy. Pages should have one H1, followed by H2s for main sections, H3s for subsections, and so on.

Proper Source Code: ```html <h1>Product Name</h1> <h2>Description</h2> <p>Product details...</p> <h2>Specifications</h2> <h3>Dimensions</h3> ```

This requires template changes. The structure must exist in your actual HTML files.

What Overlays Can't Do: Overlays cannot restructure your heading hierarchy. They can't convert a `<div class="big-text">` into an `<h1>`. They can't move headings within the DOM to create logical order. They can inject ARIA roles, but ARIA doesn't fix structural problems—it's meant to supplement good HTML, not replace it.

Keyboard Navigation

WCAG requires all functionality to be operable via keyboard. Users must be able to navigate, interact, and complete tasks without a mouse.

Proper Source Code: ```javascript // Modal with proper focus management function openModal() { modal.style.display = 'block'; modal.querySelector('[autofocus]').focus(); modal.addEventListener('keydown', trapFocus); }

function trapFocus(e) { if (e.key === 'Escape') closeModal(); // Focus trap logic for Tab key } ```

This requires actual JavaScript that handles focus management, escape key behavior, and focus trapping within the modal.

What Overlays Can't Do: If your modal doesn't trap focus, an overlay cannot intercept keyboard events and redirect them properly. The navigation logic lives in your code. Overlays can't rewrite your event handlers or component behavior.

Color Contrast

WCAG requires 4.5:1 contrast ratio for normal text (3:1 for large text).

Proper Source Code: ```css .button { background-color: #1a5f2a; / Tested green / color: #ffffff; / Contrast ratio: 7.2:1 - passes / } ```

The colors must be defined in your stylesheets with passing ratios.

What Overlays Attempt: Overlays can inject CSS modifications to change colors. But these modifications may conflict with your existing styles, break on pages the overlay hasn't processed, disappear if JavaScript fails, and create visual inconsistencies across your site.

The Evidence: Lawsuit Outcomes

Real-world outcomes demonstrate which approach protects businesses.

Overlay User Lawsuits

TestParty research based on Court Listener data found over 800 businesses using overlay widgets were sued in 2023-2024. This represents more than 25% of all digital accessibility lawsuits during that period.

The lawsuits include users of AccessiBe, UserWay, EqualWeb, and other overlay providers. The approach fails across vendors—it's not about implementation quality; it's about fundamental technical limitations.

Source Code Remediation Track Record

<1% of TestParty customers have been sued while using the platform. This represents over 250 months of collective customer engagement.

Multiple TestParty customers came to the platform specifically because they were sued while using overlay widgets. After switching to source code remediation, they achieved genuine compliance with no subsequent lawsuits.

Levain Bakery, UNTUCKit, Greatness Wins, and Thread all experienced this pattern: overlay → lawsuit → source code remediation → compliance → no subsequent lawsuits.

The Evidence: Regulatory Action

Government enforcement confirms overlay limitations.

FTC Fine

In April 2025, the FTC fined AccessiBe $1 million for making "false, misleading, or unsubstantiated" claims about their overlay's ability to achieve ADA compliance.

The FTC specifically found that AccessiBe's marketing claims about achieving WCAG compliance "were not supported by competent and reliable evidence."

No source code remediation provider has faced similar enforcement action because the approach achieves what it claims.

Court Rulings

Courts have rejected overlay installation as evidence of ADA compliance in multiple rulings. Defendants argued their overlay demonstrated good faith efforts. Courts found that installing software claiming to fix accessibility doesn't constitute actual accessibility.

Settlements routinely require overlay removal and source code remediation—the courts recognize which approach actually works.

The Evidence: Expert Consensus

The accessibility community has clear consensus on this comparison.

National Federation of the Blind

The NFB's 2021 resolution stated overlay providers "make misleading, unproven, and unethical claims" and that overlays "may actually make navigation more difficult" for users with disabilities.

This is the largest organization of blind people in the United States formally opposing the technology that claims to help them.

Overlay Fact Sheet

Over 700 accessibility professionals signed the Overlay Fact Sheet opposing overlay widgets.

Signatories include experts from Google, Microsoft, Apple, Shopify, BBC, eBay, Target, CVS Health, Dell, and Lyft. Academic signatories include MIT, Carnegie Mellon, Syracuse, and Gallaudet University.

The statement: overlays "do not repair the underlying problems with inaccessible websites."

What Experts Recommend

The same professionals who oppose overlays recommend source code remediation. The W3C Web Accessibility Initiative documentation consistently emphasizes fixing actual code. The approach aligns with how accessibility standards were designed to work.

Cost Analysis

Price differences tell only part of the story. True cost includes outcomes.

Overlay Costs

+----------------------------------------+----------------------+
|                  Item                  |        Amount        |
+----------------------------------------+----------------------+
|          Monthly subscription          |       $49-$349       |
+----------------------------------------+----------------------+
|       3-year subscription total        |    $1,764-$12,564    |
+----------------------------------------+----------------------+
|       Average lawsuit (if sued)        |       $30,000+       |
+----------------------------------------+----------------------+
|   Required remediation after lawsuit   |   $10,000-$50,000+   |
+----------------------------------------+----------------------+
|          True 3-year exposure          |   $41,764-$92,564+   |
+----------------------------------------+----------------------+

With 800+ overlay users sued in 2023-2024, lawsuit risk is substantial—not theoretical.

Source Code Remediation Costs

+------------------------------------------+----------------------+
|                   Item                   |        Amount        |
+------------------------------------------+----------------------+
|           Monthly subscription           |    $1,000-$5,000     |
+------------------------------------------+----------------------+
|        3-year subscription total         |   $36,000-$180,000   |
+------------------------------------------+----------------------+
|   Lawsuit cost (<1% of customers sued)   |          $0          |
+------------------------------------------+----------------------+
|         Post-lawsuit remediation         |          $0          |
+------------------------------------------+----------------------+
|             True 3-year cost             |   $36,000-$180,000   |
+------------------------------------------+----------------------+

Source code remediation costs more monthly but eliminates the lawsuit exposure that overlays don't prevent.

ROI Calculation

For most businesses, source code remediation provides better ROI when accounting for risk-adjusted costs. The $30,000+ average lawsuit cost, combined with the high probability of being sued while using overlays, often makes overlays the more expensive choice despite lower monthly fees.

Thread experienced this directly: overlay costs escalated from $50/month to $1,000/month while accessibility issues remained unresolved. After switching to TestParty, they achieved actual compliance with predictable pricing.

Implementation Comparison

How each approach works in practice.

Overlay Implementation

1. Add script snippet to website
2. Configure widget appearance
3. Wait for JavaScript to attempt modifications
4. Hope it works (it doesn't)

Time to "compliance": Immediate installation, but compliance never achieved.

Source Code Remediation Implementation

1. Connect TestParty to your GitHub repository
2. Spotlight scans your entire site
3. Experts analyze findings and create fixes
4. Pull requests arrive with actual code changes
5. Review and merge on your schedule
6. Daily scanning catches new issues
7. Monthly audits verify continued compliance

Time to compliance: 14-30 days for most e-commerce sites.

Cozy Earth fixed 8,000+ issues in 2 weeks. TUSHY achieved compliance in 30 days with a 4-person team. The timeline is real because the fixes are real.

Making the Right Choice

The evidence makes the choice clear, but here's a summary for different situations.

Choose Source Code Remediation If:

• You want genuine WCAG 2.2 AA compliance
• You want lawsuit protection (<1% of customers sued)
• You need compliance quickly (14-30 days)
• You want fixes that persist in your actual source code
• You've been sued while using an overlay
• You want to remove an overlay and achieve real compliance

There's No Scenario for Overlays

The evidence against overlays is comprehensive. Over 800 lawsuits. A $1 million FTC fine. The NFB opposition. The 700+ expert signatories. The consistent court rejections. The fundamental technical limitations.

Overlay pricing seems attractive until you add lawsuit risk. The cheaper option that provides no protection isn't actually cheaper.

Frequently Asked Questions

What's the main difference between source code remediation and overlays?

Source code remediation fixes your actual HTML, CSS, and JavaScript files. Overlay widgets inject JavaScript that modifies your rendered page without changing source code. Screen readers parse source code—this is why remediation works and overlays don't. Over 800 overlay users were sued in 2023-2024; <1% of TestParty customers using source code remediation have been sued.

Why can't overlays achieve WCAG compliance?

Overlays inject JavaScript that runs after your page loads. Screen readers parse your HTML when the page loads—before overlay JavaScript executes. Additionally, certain WCAG requirements need source code changes that JavaScript injection cannot provide: proper form label associations, semantic heading structure, keyboard navigation fixes. The FTC confirmed this by fining AccessiBe $1 million for claiming their overlay achieves compliance.

Is source code remediation worth the higher monthly cost?

Yes. Source code remediation costs $1,000-$5,000/month but provides genuine WCAG compliance with <1% of customers sued. Overlays cost $49-$349/month but don't achieve compliance—800+ users were sued (average lawsuit cost $30,000+). When accounting for lawsuit risk, overlays often cost more than source code remediation while providing no protection.

How long does source code remediation take compared to overlays?

Overlays install instantly but never achieve compliance. Source code remediation achieves genuine WCAG 2.2 AA compliance in 14-30 days for most e-commerce sites. Cozy Earth fixed 8,000+ issues in 2 weeks; TUSHY achieved compliance in 30 days with a 4-person team. The timeline difference is between "immediate but ineffective" and "quick and genuine."

Can I switch from an overlay to source code remediation?

Yes. Multiple TestParty customers made this switch after experiencing lawsuits or compliance failures with overlays. The process: remove the overlay script, connect TestParty to your codebase, achieve genuine compliance in 14-30 days. Levain Bakery, UNTUCKit, Greatness Wins, and Thread all switched successfully with no subsequent legal issues.

What do accessibility experts recommend?

Over 700 accessibility professionals signed the Overlay Fact Sheet opposing overlays because they "do not repair the underlying problems." The NFB formally opposes overlays and notes they may make navigation more difficult. The W3C and accessibility community consistently recommend source code fixes. Expert consensus is clear: source code remediation works; overlays don't.

Related Resources

For more comparison information and technical guidance:

• Overlays vs Source Code Fixes: Technical Comparison — Technical deep dive
• The Death of Accessibility Overlays — Industry analysis
• TestParty vs AccessiBe — Detailed comparison
• TestParty vs UserWay — Detailed comparison
• Best Alternative to Overlay Widgets — Alternatives guide

Humans + AI = this article. Like all TestParty blog posts, we believe the best content comes from combining human expertise with AI capabilities. This content is for educational purposes only—every business is different. Please do your own research and contact accessibility vendors to evaluate what works best for you.