Why is my LCP time so slow despite minimal apps and light images?

Technical Q&A
, ,

Topic summary

Main issue: Very slow Largest Contentful Paint (LCP) (~7s) despite a relatively small LCP image (~250 KB) and minimal apps.

Observations and diagnostics:

  • Google PageSpeed flags render‑blocking resources (cart.js, base.css) and unused JavaScript (Facebook Tag Manager, Facebook Connect, a mobile menu app).
  • GTmetrix suggests apps aren’t adding significant load. The LCP image is not lazy loaded. Few removable assets beyond core files.

Proposed solution (most recent update):

  • Prioritize the LCP element by setting loading=“eager” and fetchpriority=“high” on the LCP image tag, so the browser fetches it earlier and doesn’t defer it.
  • Rationale: Eager loading and high fetch priority can reduce delays specifically for the LCP resource, which image compression alone may not fix.

Notes:

  • LCP = Largest Contentful Paint, a core web vital measuring when the largest visible element renders.

Status:

  • No confirmed resolution yet. Action item is to implement the eager loading and high fetch priority change and reassess LCP. Open question: impact of these changes versus remaining render‑blocking/unused JS.
Summarized with AI on January 15. AI used: gpt-5.
1

Greetings all hope you are having a great day, I’m currently facing an issue with a very slow LCP time. I’ll give as much info as possible as I’m really confused as to why it’s so slow.

the lcp image is a Multicolumn image that is around 250kb. I’ve compressed it as much as possible so it’s a very light image.

I have barely any apps on my site and the ones I use are not taking much load time as I’ve checked on gtmetrix

the only information google insights gives me is to remove render blocking resources which is the cart js and the base css files. That’s it

also it says to remove unused JavaScript of which it lists three.
Facebook tag manager,

Facebook connect

and a mobile menu app that isn’t taking up much load time.

so for a 7 second load time it’s not really saying a great deal for me to improve.

the lcp images are not lazy loaded either

So yeah, no clue how I can improve that time. Even when I look at my usage tree that shows what loads first there’s really not much I can delete as it’s just the core files

any help is really appreciated

77ED6CD4-7582-4640-AC9E-4802498CA51D.png
77ED6CD4-7582-4640-AC9E-4802498CA51D.png828×1792 165 KB

1 Like
2

Hello DAGNORAK,

To reduce the Largest Contentful Paint (LCP), various strategies can be employed. While optimizing images is a common tactic, your attempt might not have significantly enhanced the LCP score.

An alternative approach is to assign a high fetch priority to the LCP element, ensuring it is prioritized during loading.

Additionally, rather than lazily loading all images, consider eagerly loading the LCP element.

To implement this, locate the relevant code and add ‘loading=“eager”’ and ‘fetchpriority=“high”’ attributes to the LCP element tag.

If you find my suggestion difficult to implement send and email at rajvee.kadchha@mlveda.com