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sitespeedio / sitespeed.io

sitespeed.io is an open-source tool for comprehensive web performance analysis, enabling you to test, monitor, and optimize your website’s speed using real browsers in various environments.
https://www.sitespeed.io/
MIT License
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same values in google web vitals across transactions #4297

Open prim84 opened 1 week ago

prim84 commented 1 week ago

currently we are testing client side metrics using Jmeter selenium framework. Since this framework only provides response time metrics, we are migrating to sitespeed to gather more client side metrics like FCP, LCP,CLS,TTFB, page size.

Application tested- Salesforce (It is not a SPA application . The URL changes for each transaction) Sitespeed tool version used - 34.12.1 browser time 22.10.2 coach 8.0.2 Browser used - chrome 129

How to reproduce Execute a user journey (from launch to logout scripted using javascript) and run it locally (not using docker) using the following command. node sitespeed.js --script.mjs --multi --browsertime.iterations 1 --spa

Issue For ex, if there are 5 transactions in a user journey. Except the launch transaction, all other transactions shows the same values for google web vitals (TTFB,FCP,LCP,CLS) . But the values for page metrics , CPU metrics, waterfall HAR, Coach score varies.

Transaction Name Total page transfer size Request Fully Loaded TTFB FCP LCP Launch 7 10 9.25 1.78 1.96 5.23 Login 7.6 226 21.49 2.37 2.52 9.69 Search 39.2 5 2.218 2.37 2.52 9.69 Edit 18.3 7 834ms 2.37 2.52 9.69

soulgalore commented 21 hours ago

Hi @prim84 sorry I missed your message. Those metrics are direct from the browser APIs. At the moment Chrome and other s do not update them (I think your app is SPA). Until soft navigations and browser update the APIs, they will be the same. I usually use visuals metrics for those pages to get some valuable data from the tests.