id-duplication

Detect duplicate id values.

Severity

error

❌ Incorrect

<div id="a"></div>
<div id="a"></div>

✅ Correct

<div id="a"></div>
<div id="b"></div>

Reference

• HTML Standard - The id attribute

Configuration

{
  "rules": {
    "id-duplication": "error"
  }
}