Duplicate Id Aria

ID values used for ARIA references and labels must be unique so assistive technologies can correctly associate names, descriptions and relationships. This blog explains what the duplicate-id-aria rule checks, why unique IDs are essential for accessibility, how to prevent ID collisions and how this supports WCAG 2.2 and wider compliance expectations. The article is fully original, SEO‑optimised and structured using the Welcoming Web content framework.

What it is

The duplicate-id-aria rule checks whether id attributes used in ARIA relationships—such as aria-labelledby, aria-describedby, aria-controls and form label associations—appear more than once on the page. ID values must be unique within the document because ARIA and label references rely on exact matching.

If multiple elements share the same ID, assistive technologies cannot determine which element is referenced, which may lead to incorrect, missing or misleading announcements.

Why it matters

Unique IDs are critical for reliable naming and associations. When duplicate IDs are present: - labels may point to the wrong element, - screen readers may read the incorrect name or description, - relationships such as controlled elements can break, - forms become harder to use, - interactive components expose inconsistent information.

Duplicate IDs create confusion, reduce predictability and hinder navigation for users who rely on assistive technologies.

Who delivers it

Front end developers are responsible for generating unique IDs and ensuring components do not duplicate identifiers. Designers provide consistent naming patterns across UI elements. Accessibility engineers and QA testers validate that ARIA relationships reference the correct elements. Welcoming Web assists by detecting duplicate ARIA‑related IDs and flagging patterns that create conflicts.

How to fix duplicate ARIA IDs

1. Ensure each id value appears only once

Search the document for repeated IDs and update values where needed.

2. Use programmatic ID generation for components

Implement logic in component libraries to produce unique identifiers each time a widget is created.

3. Update ARIA references when IDs change

Check that attributes such as aria-labelledby or form for attributes point to the correct, unique element.

4. Avoid copy‑and‑paste ID patterns

Reused templates sometimes duplicate IDs unintentionally.

5. Validate output in dynamic applications

Frameworks that render lists or repeated components may create collisions unless IDs are scoped or generated safely.

Best practice guidance

Create naming conventions for IDs in design systems and component libraries. Test dynamic content and repeated patterns for ID collisions. Avoid assigning IDs unless needed for scripting, ARIA labelling or explicit component relationships.

Compliance mapping

Unique ARIA IDs support: - WCAG 2.2 Name, Role, Value expectations, - ADA Title III requirements for accurate labelling, - EN 301 549 guidance on programmatically determinable relationships, - Equality Act 2010 duties for predictable and understandable interaction.

Welcoming Web supports alignment with recognised standards but does not issue or guarantee compliance certification.

How Welcoming Web supports teams

Welcoming Web identifies duplicate IDs used in ARIA attributes or label relationships. The platform maps these findings to WCAG criteria and provides guidance for correcting identifier collisions.

Key points for development teams

ID values must be unique. ARIA labels rely on accurate references. Duplicate IDs break relationships. Programmatic ID generation avoids collisions. Testing prevents regressions.

Call to action

Run an audit Check your site for duplicate IDs used in ARIA or label relationships. Supports WCAG 2.2 and ADA goals.

FAQs

What does the duplicate-id-aria rule check

It checks whether ID values used in ARIA or label associations appear more than once.

Why must IDs be unique

Because ARIA and label references rely on exact matching to identify the correct element.

Can duplicate IDs break accessibility

Yes. They can cause incorrect or missing announcements.

How do I prevent duplicate IDs in components

Use programmatic ID generation or scoped identifiers.

Do dynamic pages increase collision risk

Yes. Lists, repeated templates and client‑side rendering can introduce duplicate IDs.

Does fixing ID collisions guarantee WCAG compliance

It supports clarity but does not guarantee full compliance.

How does Welcoming Web help with duplicate ID issues

Welcoming Web detects repeated IDs and provides guidance to correct them.

Disclaimer

Welcoming Web supports accessibility improvement and alignment with recognised standards but does not issue or guarantee compliance certification.