---
title: Unique id for ARIA Labels | Accessibility Rule
description: IDs used in ARIA and labels must be unique
source_url:
  html: https://testingbot.com/support/accessibility/web/rules/duplicate-id-aria
  md: https://testingbot.com/support/accessibility/web/rules/duplicate-id-aria/index.md
---
# Ensure every id attribute value used in ARIA and in labels is unique

Rule ID: duplicate-id-ariaUser Impact: criticalGuidelines: WCAG 2.0

In HTML, the `id` attribute must be unique within a document. This uniqueness is crucial when IDs are referenced by ARIA attributes or form labels to ensure proper association and functionality.

## About This Rule

This rule ensures that every `id` attribute value used in ARIA attributes and form labels is unique within the HTML document. Adhering to this rule prevents accessibility issues and maintains valid markup.

## Why It Matters

Duplicate IDs can disrupt the accessibility and functionality of web elements. When multiple elements share the same ID, assistive technologies and client-side scripts may only recognize the first instance, leading to:

- Incorrect labeling of form fields.
- Misinterpretation of ARIA roles and properties.
- Potential scripting errors due to invalid markup.

Ensuring unique IDs helps maintain the integrity of element associations, enhancing accessibility for users relying on assistive technologies.

## How to Fix

To resolve issues with duplicate IDs:

- Audit your HTML to identify any repeated ID values.
- Rename duplicate IDs to ensure each one is unique within the document.
- Update any references (e.g., `for` attributes in labels, ARIA attributes) to match the new unique IDs.

### Example

#### Incorrect

Multiple elements sharing the same ID:

    <label for="username">Username:</label>
    <input id="username" type="text" name="user1">
    
    <label for="username">User Name:</label>
    <input id="username" type="text" name="user2">

#### Correct

Each element with a unique ID:

    <label for="username1">Username:</label>
    <input id="username1" type="text" name="user1">
    
    <label for="username2">User Name:</label>
    <input id="username2" type="text" name="user2">

## Other Rules

Interested in other web accessibility rules? Please see these other rules:

- [form-field-multiple-labels](https://testingbot.com/support/accessibility/web/rules/form-field-multiple-labels)
- [frame-focusable-content](https://testingbot.com/support/accessibility/web/rules/frame-focusable-content)
- [frame-title-unique](https://testingbot.com/support/accessibility/web/rules/frame-title-unique)
- [frame-title](https://testingbot.com/support/accessibility/web/rules/frame-title)
- [html-has-lang](https://testingbot.com/support/accessibility/web/rules/html-has-lang)