Your challenge, if you wish to accept it (and we sure hope you will), is to optimize this online portfolio for speed! In particular, optimize the critical rendering path and make this page render as quickly as possible by applying the techniques you've picked up in the Critical Rendering Path course.
To get started, check out the repository and inspect the code.
####Part 1: Optimize PageSpeed Insights score for index.html
Some useful tips to help you get started:
- Check out the repository
- To inspect the site on your phone, you can run a local server
$> cd /path/to/your-project-folder
$> python -m SimpleHTTPServer 8080
- Open a browser and visit localhost:8080
- Download and install ngrok to the top-level of your project directory to make your local server accessible remotely.
$> cd /path/to/your-project-folder
$> ./ngrok http 8080
- Copy the public URL ngrok gives you and try running it through PageSpeed Insights! Optional: More on integrating ngrok, Grunt and PageSpeed.
Profile, optimize, measure... and then lather, rinse, and repeat. Good luck!
####Part 2: Optimize Frames per Second in pizza.html
To optimize views/pizza.html, you will need to modify views/js/main.js until your frames per second rate is 60 fps or higher. You will find instructive comments in main.js.
You might find the FPS Counter/HUD Display useful in Chrome developer tools described here: Chrome Dev Tools tips-and-tricks.
- Optimizing Performance
- Analyzing the Critical Rendering Path
- Optimizing the Critical Rendering Path
- Avoiding Rendering Blocking CSS
- Optimizing JavaScript
- Measuring with Navigation Timing. We didn't cover the Navigation Timing API in the first two lessons but it's an incredibly useful tool for automated page profiling. I highly recommend reading.
- The fewer the downloads, the better
- Reduce the size of text
- Optimize images
- HTTP caching
The portfolio was built on Twitter's Bootstrap framework. All custom styles are in dist/css/portfolio.css
in the portfolio repo.
- added async attribute
- added media query
- inlined javascript
- reduced image sizes,scaled them to 115*75 pixel
- minified text
- removing font api call
- inlined css
- cached the number of pizzas in global variable items
- Calculated the five phases that animate the scrolling background pizzas outside the For Loop
- limiting DOM access by caching value of length in variable
- caching the variables to reduce DOM access
- Using .getElementByClassName or .getElementById selector instead .querySelector
- Gets all moving pizza objects from the DOM and puts them into one array to reduce DOM access
- Using backface visibility:hidden in css
- In changeSliderLabel() limiting the call to DOM tree by caching the pizzaSize element in variable 'element'
- Removed the determinDx method and adjusted their function in changePizzaSizes
- In changePizzaSizes : accessed DOM outside the for loop by caching the elements in randomPizzas