PHP: Built-in web server - Manual.
- You are using Glitch, so applications may not be fast as you would like
- At most, it took about 700ms (0.7 seconds) to load your website, pretty fast. My website usually loads in about 600ms (0.6 seconds).
- Try inlining/serving some assets locally
- Try using the webp format for your images. Learn more here
- Cache assets assets with service workers