# \--header-offset is slow on Safari with sticky elements (iPadOS 15.6)

**URL:** <https://meta.discourse.org/t/header-offset-is-slow-on-safari-with-sticky-elements-ipados-15-6/242222>\
**Category:** Bug\
**Tags:** tablet\
**Created:** [October 18, 2022, 3:54pm UTC](https://meta.discourse.org/t/header-offset-is-slow-on-safari-with-sticky-elements-ipados-15-6/242222 "2022-10-18T15:54:23Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![awesomerobot](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/awesomerobot/32/142900_2.png) [@awesomerobot](https://meta.discourse.org/u/awesomerobot)\
**Post date:** [October 19, 2022, 1:15am UTC](https://meta.discourse.org/t/header-offset-is-slow-on-safari-with-sticky-elements-ipados-15-6/242222/3 "2022-10-19T01:15:24Z")

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> [@vincefrommtl](#):
>
> I’m curious about the fonction of this variable, the Header never changes height AFAIK, outside of changing the text size, and using em for its height takes care of that.

This tends to be related to custom themes, but as you noted there are also cases like font-size that can impact the header height. In cases where the header is taller or shorter than default, we calculate the header-offset in JS to adjust other elements on the page so they’re not falling under the header.

Anyway, I can see the problem, this is definitely jarring:

but if I set `--header-offset` to a static value in CSS:

Maybe we’re calculating and updating the offset too often? We’ll do some investigation… Safari on iOS does a lot of optimization that might be causing issues.

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