Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Measuring Web Performance: Metrics & Tools
Search
Michael Geers
March 25, 2017
Technology
2
700
Measuring Web Performance: Metrics & Tools
The talk was presented on JSUnconf.eu 2017 in Hamburg
Michael Geers
March 25, 2017
Tweet
Share
More Decks by Michael Geers
See All by Michael Geers
More Hearts than Stars: Smart Charging & Community Funding
naltatis
0
120
Micro Frontends - True End-to-End Decoupling in Practice
naltatis
1
180
evcc: Sonne, Autos & dynamische Stromtarife
naltatis
0
820
Tractor Store 2.0 - TodoMVC for Micro Frontends
naltatis
0
270
Die nächste Framework Generation? Was kommt nach React, Vue.js und Angular?
naltatis
0
210
evcc – Open Source Sonne tanken
naltatis
0
1.9k
How Deep Is Your Micro Frontend
naltatis
2
880
Open Source Sonne tanken | Wallboxen mit evcc smarter machen
naltatis
1
2.5k
Energie & Feedback Loops
naltatis
1
330
Other Decks in Technology
See All in Technology
CSS、JSをHTMLテンプレートにまとめるフロントエンド戦略
d120145
0
280
GitHub Copilot の概要
tomokusaba
1
130
エンジニア向け技術スタック情報
kauche
1
250
初めてのAzure FunctionsをClaude Codeで作ってみた / My first Azure Functions using Claude Code
hideakiaoyagi
1
210
Node-RED × MCP 勉強会 vol.1
1ftseabass
PRO
0
140
ハノーバーメッセ2025座談会.pdf
iotcomjpadmin
0
160
TechLION vol.41~MySQLユーザ会のほうから来ました / techlion41_mysql
sakaik
0
180
AIのAIによるAIのための出力評価と改善
chocoyama
2
540
25分で解説する「最小権限の原則」を実現するための AWS「ポリシー」大全 / 20250625-aws-summit-aws-policy
opelab
9
1.1k
VISITS_AIIoTビジネス共創ラボ登壇資料.pdf
iotcomjpadmin
0
160
[TechNight #90-1] 本当に使える?ZDMの新機能を実践検証してみた
oracle4engineer
PRO
3
170
Agentic Workflowという選択肢を考える
tkikuchi1002
1
480
Featured
See All Featured
Dealing with People You Can't Stand - Big Design 2015
cassininazir
367
26k
Building Adaptive Systems
keathley
43
2.6k
Site-Speed That Sticks
csswizardry
10
660
Designing Experiences People Love
moore
142
24k
RailsConf 2023
tenderlove
30
1.1k
The Success of Rails: Ensuring Growth for the Next 100 Years
eileencodes
45
7.4k
Understanding Cognitive Biases in Performance Measurement
bluesmoon
29
1.8k
Large-scale JavaScript Application Architecture
addyosmani
512
110k
4 Signs Your Business is Dying
shpigford
184
22k
Exploring the Power of Turbo Streams & Action Cable | RailsConf2023
kevinliebholz
33
5.9k
Fashionably flexible responsive web design (full day workshop)
malarkey
407
66k
Optimising Largest Contentful Paint
csswizardry
37
3.3k
Transcript
MEASURING WEB PERFORMANCE Michael Geers @naltatis JSUnconf.eu 2017
WHY MEASURE?
WHAT TO MEASURE?
PAGE RESOURCES
PAGE WEIGHT • Transferred data • Slow connectivity • Metered
contracts • Optimisation • Reduce assets • Minify JS & CSS • Active gzip Chrome DevTools
# REQUESTS • Number of assets • Browser only uses
8 parallel requests per domain • Optimisation • Domain sharding • Bundling & spriting • HTTP/2
CACHABILITY • Local browser cache • Reuse already loaded assets
• Optimisations • expires / max-age header with asset-hashing • etag / last-modified
TIMINGS
• Server processing time • Browser waits for HTML •
Optimisation • Streaming templates Time to First Byte / TTFB
Page Loaded? DOMContentLoaded • Browser finished processing the HTML document
Load • All referenced assets are loaded (img, fonts, ads, tracking, …)
Custom Metrics - User Timing API window.performance .mark('sell_page_interactive')
VISUAL METRICS
• First Visual Reaction • „Critical Path“ • Optimisation •
Prioritize assets Time to First Paint https://github.com/sitespeedio/browsertime/blob/master/ browserscripts/timings/firstPaint.js
• Primary Content is Visible • above-the-fold text • e.g.
product image • „Soft metric“ Time to First Meaningful Paint https://docs.google.com/document/d/ 1BR94tJdZLsin5poeet0XoTW60M0SjvOJQttKT-JK8HI/view#heading=h.yi0gbyc627x1
• Viewport is fully rendered • Depends on screen size
Time to Visually Complete
SpeedIndex https://sites.google.com/a/webpagetest.org/docs/using-webpagetest/metrics/speed-index
SpeedIndex https://sites.google.com/a/webpagetest.org/docs/using-webpagetest/metrics/speed-index lower is better
HOW TO MEASURE?
Network Throttling Chrome DevTools | Netwerk-Tab Firefox | Responsive Design
Mode Network Link Conditioner | Hardware IO Tools for Xcode
Chrome DevTools | Timeline-Tab Low-End Device Mode
5 METRIC TOOLS
Yahoo YSlow • Calculates a score based on best practices
• Focuses on network based metrics • Recommends improvements
Google PageSpeed Insights • Analyses rendering • Critical path •
SEO relevant • Cons • Not open source (any more) • Google API-Key required • Pre-RWD • Aggressive mobile rules
WebPageTest • Father of the SpeedIndex • Solid results •
Records video • Online results • Cons • Confusing user interface • Messy selfhosting (Windows) https://www.webpagetest.org/
sitespeed.io • Docker based (selfhosting) • Visual Metrics • Modular
• Accessibility Rules • CI & Metric Integration • Cons • might contain bugs https://www.sitespeed.io/
Google Lighthouse • Chrome Extension • Command Line Tool •
Visual Metrics • First Meaningful Paint • Interaction-Metrics • Estimated Input Latency • Progressive Enhancement https://developers.google.com/web/tools/lighthouse/
GETTING REAL
Real User Monitoring • Measuring inside the users browser •
real device distribution • real browser distribution • real connectivity situations
Navigation Timing API
Resource Timing API
https://github.com/WPO-Foundation/RUM-SpeedIndex • Google project • Combines viewport & resource timing
API • Experimental RUM-SpeedIndex
boomerang.js • Collects metrics in the browser • Started by
Yahoo! <script src="boomerang/boomerang.js" /> <script> BOOMR.init({ beacon_url: "/logging" }); </script> https://github.com/SOASTA/boomerang
browsertime • Part of sitespeed.io • Leverages browser APIs https://github.com/sitespeedio/browsertime/tree/master/browserscripts/timings
No OpenSource RUM Solution :(
TIPS
Performance Budgets https://timkadlec.com/2013/01/setting-a-performance-budget/
Continuous Integration & Visualisations
Facebook 2G Tuesday • Slowdown to 2G speed for 2
hours • Opt-in dialogue the Facebook app http://www.businessinsider.com/facebook-2g-tuesdays-to-slow-employee-internet-speeds-down-2015-10?IR=T
Show don’t tell webpagetest comparison
None
Thanks for watching! Michael Geers / naltatis