---
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id: fb0129a3c7ab16247f0086d1406ca43fde13315a1a725958d58684292d5f8674
title: Fixing Performance Warnings
collection: developer
version: current
locale: en-us
portal_url: https://docs.salesforce.com/developer/current/en-us/platform/aura-platform/guides/aura/perf-warnings/perf-warnings-intro.md
canonical_url: https://developer.salesforce.com/docs/platform/aura-platform/guide/perf-warnings-intro.html
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content_type: documentation
content_hash: a32d04fb4bc35ba8d4ed7414ae5b8108419bc40e7bb31b0e4d841329fdd755c3
products:
  - Lightning Aura Components Developer Guide
  - Platform Developer Content
---

# Fixing Performance Warnings

A few common performance anti-patterns in code prompt the framework to log warning messages to the browser console. Fix the warning messages to speed up your components!

The warnings display in the browser console only if you enabled debug mode.

-   **[\<aura:if\> —Clean Unrendered Body —Clean Unrendered Body](https://developer.salesforce.com/docs/platform/aura-platform/guide/perf-warnings-if.md)**  


    This warning occurs when you change the `isTrue` attribute of an `<aura:if>` tag from `true` to `false` in the same rendering cycle. The unrendered body of the `<aura:if>` must be destroyed, which is avoidable work for the framework that slows down rendering time.

-   **[\<aura:iteration\> —Multiple Items Set —Multiple Items Set](https://developer.salesforce.com/docs/platform/aura-platform/guide/perf-warnings-iteration.md)**  


    This warning occurs when you set the `items` attribute of an `<aura:iteration>` tag multiple times in the same rendering cycle.


**See Also**  


-   [*Salesforce Help:* **Enable Debug Mode for Lightning Components**](https://help.salesforce.com/articleView?id=aura_debug_mode.htm)