How to Solve > "Reduce the impact of third-party code Third-party code blocked the main thread for 560 ms"?

Question

My PSI shifted drastically and indicates that I need to reduce the impact of third party code.

The biggest third party causing the biggest blocking time is actually identified as Google Tag Manager. Is has identified two Google tags.

Any thoughts on how to resolve this and why that would occur?

Thanks!

I tried accessing my Google Tag Manager but am not seeing options that would affect transfer size.

Answer 1

What particular metrics in PSI have shifted?

Here's some advice on managing tag managers:

• https://web.dev/tag-best-practices/
• https://www.tunetheweb.com/blog/adding-controls-to-google-tag-manager/

In general this can be summed up to:

• Ensure you regularly audit your tag managers to remove old tags that are no longer needed.
• Load tags later, to give the content a chance to load first
• Avoid custom HTML/Custom JavaScript as this can often be written in a non-performant way.