# How can I fix unsynchronized audio and video? (/en/api-reference/faq/quality/unsynchronized_video)

> For AI agents: see the complete documentation index at [llms.txt](/llms.txt).

Unsynchronized audio and video may be caused by the following:

* Slow network connection.
* Sub-optimal device performance.
* Problems with a custom video source or renderer.
* A third-party image enhancement SDK.

Complete the following steps to troubleshoot the unsynchronized audio and video.

## Step 1: Self-check [#step-1-self-check]

Check the following:

* Check whether the unsynchronized audio and video is intermittent or consistent. Occasional, intermittent unsynchronized audio and video is normal due to the nature of the network and device.

* If you use a custom video source, check whether the `timeStamp` parameter of each video frame is correct. Ensure that you are using millisecond units.

<CalloutContainer type="info">
  <CalloutDescription>
    If you use a camera to capture video, the system reports the timestamp of each video frame. That is the value you need to pass in `timeStamp`.
  </CalloutDescription>
</CalloutContainer>

* Check whether the network connection is stable. You can switch to another network connection and check if the audio and video are synchronized.

* If you use a third-party image enhancement SDK, disable it and re-check. If the audio and video become synchronized, then the third-party image enhancement SDK is the likely cause. Contact that SDK provider for technical support.

* Switch to another device with better performance, and then check if the issue persists.

* If you use a custom video renderer, check the source code of the video renderer. See the [Customer renderer](/en/video-calling/advanced-features/custom-video#custom-video-rendering) sample project provided by Agora for reference.

## Step 2: Contact Agora customer support [#step-2-contact-agora-customer-support]

If the issue persists, contact [support@agora.io](mailto\:support@agora.io). Please provide the following information to help with the troubleshooting:

* The channel name with the unsynchronized audio and video.

* The time frame when the unsynchronized audio and video appears.

* The application scenario in which the issue occurs: communication, live interactive streaming, single-hosted interactive streaming, or co-hosted interactive streaming scenario.

* The UIDs of the users sending and receiving the unsynchronized audio and video.

* Whether you use a custom video source or a custom video renderer.

* Whether the problem can be reproduced and the steps to reproduce.

* Screen recording files.

* SDK log files. See [How can I set the log file?](/en/api-reference/faq/integration/log#set-the-log-file)