- Qt 6.9
- Qt Qml
- QML Lint Warning and Errors
- Duplicate id
- Qt 6.9.2 Reference Documentation

# Duplicate id

This warning category is spelled `[syntax.duplicate-ids]` by qmllint.

## Found a duplicated id

### What happened?

You used the same value for different ids.

### Why is this bad?

The QML language forbids duplicate ids: they should all be unique in the same QML component.

### Example

     import QtQuick

     Item {
         id: root
         Item {
             id: root
         }
     }

To fix this warning, rename the duplicate to become unique:

     import QtQuick

     Item {
         id: root
         Item {
             id: notRoot
         }
     }