Solution 2 All you have to do is use the Page.IsPostBack method in your code behind. The window.onload function is widely supported by popular browsers. To get seconds for exampe from the time you did var ti = performance.now() you can do parseInt(performance.now() - ti) / 1000. Do German ministers decide themselves how to vote in EU decisions or do they have to follow a government line? How do I replace all occurrences of a string in JavaScript? I want to verify if a web page has been loaded properly. The best answers are voted up and rise to the top, Not the answer you're looking for? The function that is required to be executed is given here. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Has 90% of ice around Antarctica disappeared in less than a decade? Does Cosmic Background radiation transmit heat? This method is simple, on load check flag - if flag not exist this is first load, else set the flag: Save flag in local-storage / cookie. My assumption is: This is an incorrect assumption. Which I think it is not. Easiest way to remove 3/16" drive rivets from a lower screen door hinge? CSS files, etc.). Note:- Overriding the window.onload () function will disable any other function from attaching to it and window.onload () function sometimes respond after all the resources (images and so on) are loaded and not only the page. < % if (!Page.IsPostBack) { %> showFiltermenu (); < % } %> Solution 2 with localStorage you can save values like this: var firstTime = localStorage. Could very old employee stock options still be accessible and viable? The XHTML Note the image with the ucuc ID -- that A few months back I posted an article about how you can use your own "missing image" graphics when an image fails to load using MooTools and jQuery. If it's just a standard load though, should work fine. You can try it by running this code and then reloading the page: For historical reasons, returning a non-empty string also counts as canceling the event. But wouldnt that be covered by your basic test already? Many free web speed test tools can highlight costly third-parties including Chrome DevTools, PageSpeed Insights and WebPageTest. How does a fan in a turbofan engine suck air in? +1 for that I have added more details in below answer. If you are a new user and need to create an account, click here to access the main log in page, then click Register. Cases like post load executions or large data rendering it's consistent and the loading is consistent if defined. Once I have that then I put an explicit wait on that object as my "page load complete" test before executing anything else. It only takes a minute to sign up. I spent a few months experimenting with different approaches for writing simple, elegant and maintainable media queries with Sass. They are unreliable, and it is very likely that the JS execution scheduling during a documents parsing and displaying is delayed. So DOMContentLoaded definitely happens after such scripts: In the example above, we first see Library loaded, and then DOM ready! (all scripts are executed). Can (a== 1 && a ==2 && a==3) ever evaluate to true? window.onload on the other hand will over-write them. If we have a script after the style, then that script must wait until the stylesheet loads: The reason for this is that the script may want to get coordinates and other style-dependent properties of elements, like in the example above. My approach is: Verify the URL is shown as expected. You can divide by 1000 to get seconds. in the if statement. See how your page loads on different devices. Asking for help, clarification, or responding to other answers. worked perfectly for my case where no events seem to work as well. Find centralized, trusted content and collaborate around the technologies you use most. How do I pass command line arguments to a Node.js program? This is quite a good result, as only 25% of websites can load faster. How does a fan in a turbofan engine suck air in? Step 1. Is it possible? And with custom reports and easy-to-understand dashboards, you'll bring clarity, visibility and consistency to your entire learning program. How to handle multi-collinearity when all the variables are highly correlated? Why does my JavaScript code receive a "No 'Access-Control-Allow-Origin' header is present on the requested resource" error, while Postman does not? Using timings initiated with a