10 things you can do to speed up your web app today

10 Things You Can Do Today To Speed Up Your

Web Application

Chris Love

@ChrisLove

Love2Dev.com

Who Am I

• ASP.NET MVP• ASP Insider• Internet Explorer User Agent• Author• Speaker• Tweaker, Lover of Web, JavaScript, CSS & HTML5• @ChrisLove• Love2Dev.com

High Performance Single Page Web Applications• Responsive Design• Touch• Mobile First• SPA• Extensible, Scalable Architecture• Web Build and Workflow• Goes Really Fast!

• ~395 Pages• 20 Chapters• $9.99 http://amzn.to/1a55L89

BUY NOW!

Slide Deck & Source Code

• Slide Deck – slidesha.re/15YTrTT• Source Code – http://GitHub.com/docluv

Annoying?

Web Performance Optimization

Web performance optimization, WPO, or website optimization involves ongoing monitoring and testing of websites to achieve optimum performance under given constraints. Usually optimization is restricted due to lack of complete information and metrics to evaluate the performance of a website.

http://bit.ly/SWEh6E

Matt Cutts

"Also take a step back for a minute and consider the intent of this change: a faster web is great for everyone, but especially for users. Lots of websites have demonstrated that speeding up the user experience results in more usage. So speeding up your website isn’t just something that can affect your search rankings–it’s a fantastic idea for your users.“

http://bit.ly/SPPB4k

Time is Money

• Faster Sites Have Higher Conversion Rates

• WalMart - http://bit.ly/S1fHSZ• Google – http://bit.ly/WajJbB• Amazon – http://bit.ly/S3UoAj• ShopZilla - http://bit.ly/RIQMDM

WalMart

Folks at Walmart knew their pages were slow. As a for instance, initial measurement showed that an item page took about 24 seconds to load for the slowest 5% of users. Why? The usual culprits: too many page elements, slow third-party scripts, multiple hosts (25% of page content is served by partners, affiliates, and Marketplace), and various best practice no-nos

http://bit.ly/WajJbB

Google’s ½ Second

Half a second delay caused a 20% drop in traffic. Half a second delay killed user satisfaction.The lesson, Marissa said, is that speed matters. People do not like to wait. Do not make them.

http://bit.ly/TPPhUp

Fast Facts

• 57% Will Abandon a Slow Site After 3 Seconds

• We Have to Concentrate 50% Harder For Slow Sites

• 78% Have Felt Stress or Anger With Slow Sites

• 44% Say Slow Sites Make Them Anxious

• 4% Have Thrown Their Phone

http://bit.ly/SuBLDR

Web Sites Are Getting Fat

http://httpArchive.org

93 Files Requests - 1.7MB

17 JavaScript Files - 276KB

5.6 CSS Files – 48KB

53 Images - 1068KB

16 Domains

46% Cacheable

Web Sites Are Getting Larger

That's Great But I Work in the Enterprise

Performance IS Relevant

• Do you really want to waste $$$• You want to make co-workers hate you?• And Possibly Throw a Phone at You

• Remember the Physiological Stats?• Slow Web Apps Have Higher Data Entry Error Rates• Oh And You Are Going Mobile

http://bit.ly/16zFCXL

Good Code Is Cheaper

• Performance Best Practices Lead To:• Well Structured Code• Smaller Code

• Easier Maintenance• Fewer Bugs

• Encourages Development Best Practices• Encourages Discipline

OK How Do I Figure Out How to Fix Things?

Southwest.com• 89 File Requests

• 5 Domains

• 2 CSS

• 8 Documents

• 39 Images

• 24 JavaScript Files

• 4 AJAX Calls

• 1MB

• 336B Request Header

• 1KB Cookie

• 2034 DOM Elements

webpagetest.org

• Online Tool• Identifies Common Performance Issues• Must be Public URL

http://bit.ly/1dibffr

Southwest.com

http://bit.ly/1dibffr

http://bit.ly/1dibffr

F12 To the Rescue!!

Waterfall Chart

Examine A Http Request

YSlow Rules

1. Minimize HTTP Requests2. Use a Content Delivery Network3. Avoid empty src or href4. Add an Expires or a Cache-Control Header5. Gzip Components6. Put StyleSheets at the Top7. Put Scripts at the Bottom8. Avoid CSS Expressions9. Make JavaScript and CSS External10. Reduce DNS Lookups11. Minify JavaScript and CSS12. Avoid Redirects13. Remove Duplicate Scripts14. Configure ETags15. Make AJAX Cacheable

16. Use GET for AJAX Requests17. Reduce the Number of DOM Elements18. No 404s19. Reduce Cookie Size20. Use Cookie-Free Domains for

Components21. Avoid Filters22. Do Not Scale Images in HTML23. Make favicon.ico Small and Cacheable

http://yhoo.it/W7BFIw

1. Add A Fav Icon – Eliminate 404s

“Most of your scaling problems wont be glamorous“

Mike Kriegerhttp://bit.ly/QeKZsO

Make FavIcon Small and Cacheable

• Don’t Return 404• YSlow Rule #18

• Make Sure Its Compatible• PNG/ICO

• It Carries Cookie Weight

• Instagram Lesson #1http://bit.ly/RUXEiL

2.Use a CDN

• Globally Distributes Resources Closer to Client• Was Expensive• Amazon CloudFront cost pennies a month

3. Far Future Expires Header

• Lets the Browser Cache Resources Locally• Eliminates Future Http Requests• The Fastest Http Request is the one not made• Only Updates Resource if Changed on Server

4. Use LocalStorage For Storage & Caching

• Allows You to Keep Data Locally in a Hash Table

• localStorage

• sessionStorage

• Approximately 5-10MB

• Replace Cookies

• Great For Caching

AJAX Prefilter

• Checks localStorage Before Making AJAX Call• Stores Data in localStorage with Expiration Value• Radically Reduces Http Requests• Radically Improves Performance

5. Optimize Images

• Images are Too Large• PNGCrush, Kraken.io• Image Sprites• Glyph Fonts• Data URIs• CSS Rules

37

• CSS Sprites• Consider Gyph/Icon Font• CSS Gradients, Border Radius, Shadows• Text• This is a 30KB Image – Possible Change to 0KB*

6. No More Cookies

• Cookies Add Weight• Place Resources (img/css/js) on

Cookieless Domains• CDNs Are Great For No Cookies• Consider Local Storage Instead

39

SWA & Cookies

40

Impact of Cookies on Response Time

41

Is 78ms A Big Deal???

• Remember 95 Files• 95 * 78ms = 7410ms or 7+ Seconds• Does Cause Delay• Parallel Downloads Help Overall Time

• Don’t Use 95 Files, Duh

7. Bundle & Minify CSS & JavaScript

• Eliminate Excess HTTP Requests• Reduces Data Footprint• This is a Release or Production Version• Shoot for a Single JS and a Single CSS file in Production

Use A Client Build System

• Bundling & Minification is OK• Grunt Is Very Easy & Extensive• Validate Scripts• Combine & Minify Scripts• Validate CSS• Combine & Minify CSS• Many Other Tasks

• http://bit.ly/1kcrpuo

Using Grunt JS

• Setup Using NPM• npm install -g grunt-cli

• Add Grunt files• package.json• grunt.js

Common Contrib Extensions

• Uglify• JSHint• Handlebars• HTMLMIN• Jasmine• Qunit• Watch• YuiDoc

Package.json

46

{ "name": “webmovies", "version": "0.0.4", "devDependencies": { "grunt": "~0.4.1", "grunt-contrib-jshint": "~0.1.1", "grunt-contrib-nodeunit": "~0.1.2", "grunt-contrib": "~0.6.1" }}

Grunt.js

8. Gzip Text Content

• Browsers Support Gzip & Deflate Algorithms• Reduces Text Base Content Size• Makes it Easier to Traverse Intertubes• 14kb Critical Packet Size• This is the Goal for Optimal Mobile Performance

Configure Gzip in IIS

Configure Gzip in Amazon S3 | CloudFront

9. CSS @ Top – JavaScript @ Bottom

• CSS is Read & Evaluated to Build CSSOM• Late CSS causes Browser to ‘Start All Over’• JavaScript is a Blocking Action• Browser Stops Everything• Script Must Be Loaded• Script Must Be Evaluated

• Use Async & Defer Attributes

10. External CSS & JavaScript

• Allows Resources to be Cached Independently of Markup• Reduces Page Weight

• Reduces Chance of Duplicate Code• Can Be Bundled & Minified

Critical Rendering Path

Bonus – Use AppCache

• <html lang="en-US" manifest="ie11WebSite.appcache">• Stores Resources Locally in a Sandbox Cache for the Domain• Available Offline• Has an Event API

Bonus – Use AppCacheCACHE MANIFEST

# version 0.07

CACHE:

#images

favicon.ico

img/purple-bkg.jpg

#css

css/site.min.css

#js

js/applib.js

NETWORK:

#http://example.com/api/

#http://api.rottentomatoes.com/api/public/v1.0/

FALLBACK:

#http://content9.flixster.com/movie/*.jpg /img/offline-poster.png