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The Ultimate Guide to Web Performance πŸš€

ender_minyard profile image ender minyard Updated on ・5 min read

There's so many ways to speed up your site. Don't you wish every web performance tip was in one place? That's what I thought too, so I put them all in one place: this post.

Use this guide as a reference.


Table Of Contents

HTML

✨ Minify HTML
β˜„οΈ Order your styles and scripts for pagespeed
⚑️ Eliminate render-blocking resources
🌟 Minimize layout thrashing
πŸŽ‰ Prioritize resources
✨ Preload critical assets to improve loading speed
πŸ’₯ Establish network connections early
⚑️ Prefetch resources
🌟 Implement adaptive serving

CSS

⭐️ Minify CSS
✨ Remove unused CSS
πŸ’₯ Defer non-critical CSS
⚑️ Minimize CSS requests by combining external CSS
πŸš€ Optimize CSS background images with media queries
⭐️ Avoid CSS inside the body tag
β˜„οΈ Inline critical CSS
✨ Avoid expensive styles
πŸ’« Optimize CSS length

Images

✨ Choose the right image format
πŸ’« Choose the correct level of compression
⭐️ Use Imagemin to compress images
πŸ’₯ Defer offscreen images
⚑️ Properly size images
✨ Replace animated gifs with video
πŸŽ‰ Serve responsive images
⚑️ Serve images with correct dimensions
🌟 Use WebP images
⚑️ Use AVIF images
🎊 Use image CDNs to optimize images
✨ Use lazy-loading
πŸš€ Lazy-loading video
⚑️ Use lazysizes to lazy-load images
⭐️ Compress JPEG images
πŸ”₯ Optimize PNG images
✨ Optimize SVG vector files

Fonts

πŸ’« Avoid invisible text during font loading
πŸ’₯ Use preconnect to load fonts faster
⚑️ Optimize Webfont loading and rendering
β˜„οΈ Reduce Webfont Size
✨ Keep Webfont size under 300kb

JavaScript

πŸ’« Apply the PRPL pattern
⭐️ Limit the size of NPM dependencies
⚑️ Use code splitting
🌟 Combine external JavaScript
πŸ’₯ Remove unused code
πŸŽ‰ Use tree-shaking in Webpack
✨ Minify JavaScript
πŸ’« Serve modern code to modern browsers
🌟 See how CommonJS makes your bundles larger
⚑️ Defer loading JavaScript
⭐️ Prefer Vanilla JavaScript🎊
πŸ’‘ Use service workers to cache data
🎊 Use web workers
πŸ’₯ Write optimized code for V8
πŸŽ‰ Compile your JavaScript to faster JavaScript with Prepack
✨ Compile your JavaScript to faster JavaScript with Closure Compiler

Server

β˜€οΈ Use HTTPS
β˜„οΈ Keep the size of cookies low as possible
πŸ”₯ Avoid bad requests
πŸ’« Set HTTP cache headers
⭐️ Enable gzip and brotli compression
⚑️ Self-host your static asssets
🌟 Enable OCSP stapling
πŸ’₯ Adopt IPv6
πŸ’‘ Serve assets over HTTP/2
πŸŽ‰ Implement HPACK compression
✨ Set proper security headers

Testing Tools

πŸ’« Measure site speed with Pingdom
🌟 Measure site speed with WebPageTest
🎊 Measure performance with the RAIL model
⚑️ Configure Webpack performance hints
⭐️ Use bundlesize
πŸ’₯ Measure JavaScript execution time
πŸŽ‰ Use lighthouse-ci
β˜„οΈ Use Lighthouse Bot to set a performance budget
β˜€οΈ Test on remote real devices
πŸ”₯ Use Sitespeed
✨ Use Calibre
πŸ’« Use SpeedCurve
🎊 Use k6
⚑️ Use SpeedTracker

Frameworks

⭐️ Use an ahead of time compiler
πŸ’₯ Improve Angular performance
β˜€οΈ Debug React perfomance
πŸ”₯ Eliminate common React issues
✨ Make components connection aware
πŸ’« Implement adaptive serving
πŸŽ‰ Serve Adaptive Components Using the Network Information API




Did I miss something? Comment any potential additions to the list!

Posted on by:

ender_minyard profile

ender minyard

@ender_minyard

Web performance, web workers, and multi page applications.

Discussion

pic
Editor guide
 
 

This deserves a github repository .
like Awesome web performance..

 

Nice! Lots of goodies in here and this is a great checklist.

The CSS section should have something like:

β€œInline Your Critical CSS” which reduces the number of requests and helps with render blocking.

 
 

Nice thanks! I didn’t know about that Library.

 
 

Just dope?

 

What can I say, it's just what I needed to do that πŸ˜†

Yo that's dope.

 

Amazing list you put there!! πŸŽ‰πŸŽ‰ Thank you!

I have a few additions there you might want to include:

 

Great job buddy, Thanks for sharing it, You may also visit to testingxperts.com/services/perform... to grab more knowledge about performance testing.

 

THIS IS A GODSEND!!!!!!!!
How long did this take you to prepare?

 

How many of these amazing posts do you make? πŸ˜€ I guess I just got to go read all of them.

 

:-) thanks!

 

I would add this one: Serve Modern Code to Modern Browsers for Faster Page Loads web.dev/serve-modern-code-to-moder...

 

That's already in the article :-)

 

Sorry I completely missed it! πŸ™ƒ

 

You could add a critical-path sections, there may be some tools / techniques here for you to add to yours:

github.com/addyosmani/critical-pat...

:)

 

The article already links to Addy Osmani's Critical library.

 

Impressive list, very complete!

 

Excellent list. Please add JMeter under testing tools.

 
 

content-visibility - limited browser support right now.

web.dev/content-visibility/

caniuse.com/css-content-visibility

 

That's just awesome. πŸ‘πŸ’―

 

Also a follow up: add AVIF format to images

reachlightspeed.com/blog/using-the...

 
 

This is very useful list

 

Thanks I can create my own checklist now

 

The suggestion to combine CSS and other types of files, is that still true in the age of http2 and the probably soon coming of http3?

 

HTTP requests are still expensive. I personally make an exception to bundling for very large JS files (which you should avoid in the first place). In the past, with benchmarking, I found that bundling small files = performance gains but bundling large JS files = more execution time.

There are limitations to bundling due to file size, but also, HTTP/2 adoption isn't universal. You may be interested in this other article about bundling.

There is definitely a way to bundle correctly. For example, if you generate different bundles on every build, you have to consider that the user never gets to cache your assets.

 

Thanks a ton for collating them.