What is the issue?
Pages that aren't compressed can slow down the speed of your website. Slow loading times mean lower conversion rates and higher bounce rates, as users are more likely to go to a competitor rather than wait for your page to load.
How to fix
Use Google Analytics data to find which pages receive the highest amount of sessions, and prioritize these pages. Slow pages can cause a poor onsite experience, higher bounce rates, and lower conversion rates. Learn more in this article.