For performance testing testing Jmeter UI - endpoint - response time deferring from developer tool loading time
Ex Jmeter - endpoint response time is 615 Ms where in developer tool shows (Load: 13.30 s) Finish: 18.98 s
Note : Jmeter capturing 35 backend call/ Developer tool capturing 104 backend call
why jmeter couldn't capture all developer tool backend calls?
why jmeter couldn't capture all developer tool backend calls? do we have any solution for this issue
As per JMeter project main page:
JMeter is not a browser, it works at protocol level. As far as web-services and remote services are concerned, JMeter looks like a browser (or rather, multiple browsers); however JMeter does not perform all the actions supported by browsers. In particular, JMeter does not execute the Javascript found in HTML pages. Nor does it render the HTML pages as a browser does (it's possible to view the response as HTML etc., but the timings are not included in any samples, and only one sample in one thread is ever displayed at a time).
So apart from configuring JMeter to behave like a real browser when it comes to handling embedded resources, cookies, think times and so on you need to pay attention to the nature of the requests which are being called when you open the page in the browser.
If the request is created by JavaScript, i.e. it's an AJAX call JMeter won't make the request automatically when you open the page. However you can record it using JMeter's HTTP(S) Test Script Recorder and run after the main request. The cumulative response time can be measured using Transaction Controller
Check the Retrieve All Embeded Resources in Advanced tab of the http sampler and see what is the difference.
Times will be always slightly different between dev tools and Jmeter or between JMeter and other performance tools like Gatling for example.
