Extreme Web Performance for Mobile Devices - Velocity NY

extreme web performance for mobile devices

maximiliano @firtman firt.mobi

New York, Sep 15 2014

Slides, links and tests firtman.github.io/velocity

questions

yes, please !

QA at the end office hours tomorrow

performance + mobile + web

1- Mobile Web today 2- Performance & Mobile 3- Tools 4- Initial loading & perception 5- Responsiveness & experience

1- mobile web today*

*today: september 2014

1- mobile web today

- Web Platforms - The Android’s problem

web platforms

iOS and Android

web platforms

Adobe Digital Index NetMarketShare Akamai.io Wikimedia Stats StatCounter MOVR by WURFL

web platformsLinks at firt.mobi/velocity

web platformsOthers

4%

Windows Phone 3%

Opera 5%

iOS!50%

Android!38%

web platformsOthers

4%

Windows Phone 3%

Opera 5%

iOS!50%

Android!38%

Others?

• Firefox • UC Browser • Nokia Browser • BlackBerry Browser

web platforms

iOS!50%

Safari!100%

web platforms

iOS!50%

6.x!11%

7.x!89%

Source: Apple

web platforms

Safari iOS6 5%

Safari iOS7!45%

Android!38%

web platforms

Android!38%

web platforms

Android!38%

Browser!64%

Chrome!36%

web platforms

web platforms

web platforms

LG G3

web platforms

Android!38%

Samsung!22%

Browser!42%

Chrome!36%

web platforms

Android!38%

4.4

4.1-4.3

4.0

2.3

Source: Android Dashboard

web platformsOthers

4%

Windows Phone 3%

Opera 5%

iOS!50%

Android!38%

web platforms

Samsung!10%

Android!15%

Others 4%

Windows Phone 3%

Opera 5%

Safari iOS6 5%

Safari iOS7!45%

Chrome!14%

Others?

• Firefox • UC Browser • Nokia Browser • BlackBerry Browser

1- mobile web today

- Understand the real ecosystem - Android browsers - Don’t think you are an average user - May change future

2- mobile & performance

- Perception - Differences - Cellular networks - Responsive Web Design

immediate feedback 100ms

!

perception

Jakob Nielsen - Usability Engineering

immediate feedback 100ms

losing user’s flow of thoughts 1s

perception

Jakob Nielsen - Usability Engineering

500ms delay, +26% user’s frustration

perception

Source: Radware

why do we need special care on mobile?

CPU and GPU

Memory

differences

CPU and GPU

Memory

differences

5x

Long tail persists

differences

Source: MOVR by ScientiaMobile

Wifi

differences

Wifi, public spaces?

differences

Cellular connections

differences

We have 4G! We don't need to worry about performance...

(

)

cellular

0

25

50

75

100

US Western Europe Asia Global

4G 2G/3G

Only 4% is on 4G globally

cellular

0

25

50

75

100

US Western Europe Asia Global

4G 2G/3G

~30% of the time 4G was not used

Real Bandwidth (Mbps)cellular networks

0 2 4 6 8

2G 3G Wifi 4G

RTT - latencycellular networks

2G

3G

4G

Home

0 250 500 750 1000

Min Max

latency

request

bandwidth

responsive web design

Responsive Web Design is a TOOL

Responsive Web Design is NOT a GOAL

Users DON’T care if your site is RESPONSIVE

(in terms of RWD)

Users DO care if the site is FAST

Page size

mobile vs desktop

responsive web design

Much smaller!6%

Slightly smaller!22%

Same Size!72%

Source: guypo.com

Superbowl advertisers

mobile approach

responsive web design

Responsive site!50%

Desktop!7%

Mobile !43%

Source: blogs.keynote.com

2- mobile and performance

- Perception: 1s threshold - RTT latency - Test on low hardware and 2G/3G !

3- tools

3- tools- where - measuring loading times - measuring responsiveness - online tools - html5 apis

Simulator & Emulator

Real device

where

emulators

Samsung!10%

Android!14%

Others!4%

Windows Phone 3%

Opera 5%

Safari iOS6 5%

Safari iOS7!45%

Chrome!14%

emulators

Samsung!10%

Android!14%

Others!4%

Windows Phone!3%

Opera 5%

Safari iOS6 5%

Safari iOS7!45%

Chrome!14%

emulators

Samsung!10%

Android!14%

Others!4%

Windows Phone 3%

Opera 5%

Safari iOS6 5%

Safari iOS7!45%

Chrome!14%

DEMO

online tools

online tools

remote inspectors

remote inspectors

Samsung!10%

Android!14%

Others!4%

Windows Phone!3%

Opera 5%

Safari iOS6 5%

Safari iOS7!45%

Chrome!14%

Measuring

DEMO

Proxies / Network sniffers

• Charles Proxy • Fiddler

tools

Image from telerik fiddler

Connection simulators

• Network link conditioner (Mac/iOS) • Charles Proxy • Clumsy for Windows • Net Limiter for Windows • SlowyApp for Mac • Chrome Developer Tools

tools

Navigation Timing API

• window.performance • Timestamps available

html5 apis

navigation timing api

Samsung!12%

Android*!12%

Others!4%

Windows Phone!3%

Opera 5%

Safari iOS6!5%

Safari iOS7!45%

Chrome!14%

* Android browser only from 4.0

Navigation Timing APIhtml5 apis

In just 2 days…

navigation timing api

Samsung!12%

Android!12%

Others!4%

Windows Phone!3%

Opera 5%

Safari iOS6/7!15%

Safari iOS8!35%

Chrome!14%

in a few weeks…

Navigation Timing APIhtml5 apis

DEMO

Resource Timing API• Information per resource • Chrome and IE11 only

html5 apis

Network information API

• Android Browser, Silk (spec #1) type • BlackBerry 10, old Firefox (spec #2) bandwidth • Firefox, Chrome for Android 38+ (spec #3) type

html5 apis

3- tools

- Learn where to test - Measure loading times - Measure responsiveness - HTML5 APIs !

4- initial loading & perception

4- initial loading & perception- 1 second threshold - classic checklist - ATF and the rest - responsive web design - future visits

Image from developers.google.com

What!!? Do you expect a page load in 200ms?

(

)

No really, we just need the PERCEPTION

Let’s see HOW

= REDIRECTS

Redirects

• From 150 to 1000 ms per redirect • mydomain.com -> m.mydomain.com • URL shorteners

Redirects

DEMO

= APP BANNER

• From 1 to 5s !

idontwantyourfuckingapp.tumblr.com

Basic browser behavior

• Network Fetch • Parsing • Rendering

Basic browser behavior

HTML

JS CSS

Basic browser behavior

HTML

JS CSSBLOCKS PARSING BLOCKS RENDERING

The 14K limit

The 14K limit

• TCP slow start • Initial congestion window: ~14.6Kb (compressed) • > 14Kb will create another roundtrip

RTT

We need to separate ABOVE THE FOLD (ATF)

content

ATF in 1s = 1 RTT ~ < 14Kb !

!

HTML + CSS + JavaScript Images?

ATF

Avoid JavaScript frameworks

• Embrace Vanilla JS • If you really need them, load them after ATF • Think on alternatives or partial frameworks

ATF

Careful with Data URI in CSS

• Images are non-blocking by default • Using Data URI in CSS creates blocking images • Use them only on non-ATF external CSS

ATF

Compress resources

• Use Gzip in HTTP • For text-based files only

Client side rendering

• Careful with client-side frameworks • Try to render the initial view server-side • Render at least a basic view

ATF

Client side rendering

• Careful with client-side frameworks • Try to render the initial view server-side • Render at least a basic view

ATF

5x

Use illusion tricks

• Loading content animation • Minimal-ui viewport ASAP (RIP) • Remember to keep the user engaged in 1s

ATF

Web Fonts• Blocks text rendering • Fonts are bigger than 14Kb • Use them with care • Remove characters • Simplify glyphs

ATF

Responsive Web Design

Responsive Web Design

• Media queries block rendering (all of them) • ATF content on mobile is not the same

DON’T rely on RWD techniques only

for first view

RESPONSIVE WEB DESIGN is the future

We are not saying go m.*

Responsive Web Design

• Using same URL for mobile/desktop still a good a idea • Mix it with RESS / adaptive web design • Load media queries CSS async • Use server-side libraries • WURFL or DeviceAtlas

After ATF is ready

• Load rest of your content • Gain experience while rendering ATF: current performance, screen density, bandwidth • Make decisions: HD/SD

Async scripts

<script async src=""></script> HTML5

Defer non-ATF CSS

• No defer or async attributes (yet) • Inject <link> after rendering • load, requestAnimationFrame

Speed future visits

• Be cache friendly • Use Application Cache for ATF content • Create a custom cache

4- initial loading & perception

- ATF in 1s (illusion) - No redirects, GZip, no scripts - Only ATF CSS, careful with fonts - Defer anything else !

5- responsiveness & experience

4- responsiveness & experience

- consistent frame rate - immediate feedback - scrolling - your new enemy

Keep framerate high and consistent

• Main UI thread as free as possible • Avoid repainting (software bitmap calculations)

consistent fps

JavaScriptframerate

• Avoid DOM manipulations inside loops/scroll

var e = document.querySelector("#test");for (var i=0; i<100; i++) { // change e attributes });

JAVASCRIPT

CSSframerate

• Promote GPU layers smartly selector {

-webkit-transform: translateZ(0); -webkit-perspective: 1000; } !

selector { z-index: 10; }

CSS

Animationsframerate

• Don’t animate from JavaScript for basic stuff • Use requestAnimationFrame

remember 100ms immediate feedback?

Immediate feedback

• The 300ms delay !

• mobile viewport (“user-scalable=no” on some browsers) • FastClick solution

Immediate feedback

!

• FastClick solution

Immediate feedback!

• Mobile Viewport on Chrome

<meta name=viewport content="width=device-width">

HTML

Immediate feedback!

• Mobile Fixed Viewport on IE <meta name=viewport content="width=device-width, user-scalable=no" >

HTML

Immediate feedback!

• CSS on IE html { -ms-touch-action: manipulation; touch-action: manipulation; }

CSS

Distract the user

Storage for immediate feedback

• web storage vs web sql vs indexeddb • think about async vs sync • Finally IndexedDB on iOS 8!

navigator.geolocation .getCurrentPosition(cbOK, cbKO, { maximumAge: 60000 });

JAVASCRIPT

Geolocation cache

Scrolling

Scrolling

• avoid re-painting • use touch overflow for momentum • don’t use JavaScript scrollers • on large scrolling areas: copy native

Large scrolling areas

Let’s copy native frameworks: • iOS: UITableView • Android: ListView & Adapters

Large scrolling areas

• Object pool !

Infinite scroll

• DOM vs. iframe vs. object pool • changes on iOS8

Your new enemy

NOT THE USER

YOUR DESIGNER

Careful with some design features

• GPU vs CPU repaint • Important on scroll, transitions & animations

Careful with some design features

• Transforms: translate, scale, rotate and opacity GPU • border-radius, gradients, shadows, filters CPU repaint

300 CSS pixels

300 1.00 390 1.30 450 1.50 600 2.00 672 2.24 900 3.00 1200 4.00 !

!

device px px ratio Firefox OS

Galaxy SIIiPhone 5/6BB Z10iPhone 6 Plus

Nexus 7

LG G3

Careful with some design features

• Deliver super high resolution images

5- responsiveness & experience- 100s feedback - Consistent fps - Avoid CPU repaints - Embrace GPU smartly - Profile & test !

Picture from Simon Howden freedigitalphotos.net!

Picture from Simon Howden freedigitalphotos.net!

uf! we've covered a lot!

1- Mobile Web today 2- Mobile Performance 3- Tools 4- Initial load & perception 5- Responsiveness & experience

Slides, links and tests firtman.github.io/velocity

final thoughts

- measure and profile on the real world - don’t redirect, reduce requests - atf content in 1s, defer the rest - be simple, be aggressive

you can reach a good experience

Pictures)from)freedigitalphotos.net)

twitter: @firt mobilexweb.com

firt.mobi/pmw Book signing: Wed 10.45am

Office Hours: Tue 10.45am