Here is a collection of tools I’ve found useful.

Page Speed:

• Google PageSpeed Insights: pagespeed.web.dev
• GTmetrix: gtmetrix.com
• WebPageTest: webpagetest.org (Useful for waterfall chart and list of all loaded files)

Social

• Preview Open Graph data for any page: omgimg.co/social/preview

Images

• Convert SVG to CSS: yoksel.github.io/url-encoder