JavaScript hard refresh of current page

Question

How can I force the web browser to do a hard refresh of the page via JavaScript?
Hard refresh means getting a fresh copy of the page AND refresh all the external resources (images, JavaScript, CSS, etc.).

Answer 1

⚠️ This solution won't work on all browsers. MDN page for location.reload():

Note: Firefox supports a non-standard forceGet boolean parameter for location.reload(), to tell Firefox to bypass its cache and force-reload the current document. However, in all other browsers, any parameter you specify in a location.reload() call will be ignored and have no effect of any kind.

Try:

location.reload(true);

When this method receives a true value as argument, it will cause the page to always be reloaded from the server. If it is false or not specified, the browser may reload the page from its cache.

More info:

• The location object

Answer 2

window.location.href = window.location.href

Answer 3

This is a 2022 update with 2 methods, considering SPA's with # in url:

METHOD 1:

As mentioned in other answers one solution would be to put a random parameter to query string. In javascript it could be achieved with this:

function urlWithRndQueryParam(url, paramName) {
    const ulrArr = url.split('#');
    const urlQry = ulrArr[0].split('?');
    const usp = new URLSearchParams(urlQry[1] || '');
    usp.set(paramName || '_z', `${Date.now()}`);
    urlQry[1] = usp.toString();
    ulrArr[0] = urlQry.join('?');
    return ulrArr.join('#');
}

function handleHardReload(url) {
    window.location.href = urlWithRndQueryParam(url);
    // This is to ensure reload with url's having '#'
    window.location.reload();
}

handleHardReload(window.location.href);

The bad part is that it changes the current url and sometimes, in clean url's, it could seem little bit ugly for users.

METHOD 2:

Taking the idea from https://splunktool.com/force-a-reload-of-page-in-chrome-using-javascript-no-cache, the process could be to get the url without cache first and then reload the page:

async function handleHardReload(url) {
    await fetch(url, {
        headers: {
            Pragma: 'no-cache',
            Expires: '-1',
            'Cache-Control': 'no-cache',
        },
    });
    window.location.href = url;
    // This is to ensure reload with url's having '#'
    window.location.reload();
}

handleHardReload(window.location.href);

Could be even combined with method 1, but I think that with headers should be enought:

async function handleHardReload(url) {
    const newUrl = urlWithRndQueryParam(url);
    await fetch(newUrl, {
        headers: {
            Pragma: 'no-cache',
            Expires: '-1',
            'Cache-Control': 'no-cache',
        },
    });
    window.location.href = url;
    // This is to ensure reload with url's having '#'
    window.location.reload();
}

handleHardReload(window.location.href);

Answer 4

Accepted answer above no longer does anything except just a normal reloading on mostly new version of web browsers today. I've tried on my recently updated Chrome all those, including location.reload(true), location.href = location.href, and <meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate" />. None of them worked.

My solution is by using server-side capability to append non-repeating query string to all included source files reference as like below example.

<script src="script.js?t=<?=time();?>"></script>

So you also need to control it dynamically when to keep previous file and when to update it. The only issue is when files inclusion is performed via script by plugins you have no control to modify it. Don't worry about source files flooding. When older file is unlinked it will be automatically garbage collected.

Answer 5

Changing the current URL with a search parameter will cause browsers to pass that same parameter to the server, which in other words, forces a refresh.

(No guarantees if you use intercept with a Service Worker though.)

  const url = new URL(window.location.href);
  url.searchParams.set('reloadTime', Date.now().toString());
  window.location.href = url.toString();

If you want support older browsers:

if ('URL' in window) {
  const url = new URL(window.location.href);
  url.searchParams.set('reloadTime', Date.now().toString());
  window.location.href = url.toString();
} else {
  window.location.href = window.location.origin 
    + window.location.pathname 
    + window.location.search 
    + (window.location.search ? '&' : '?')
    + 'reloadTime='
    + Date.now().toString()
    + window.location.hash;
}

---

That said, forcing all your CSS and JS to refresh is a bit more laborious. You would want to do the same process of adding a searchParam for all the src attributes in <script> and href in <link>. That said it won't unload the current JS, but would work fine for CSS.

document.querySelectorAll('link').forEach((link) => link.href = addTimestamp(link.href));

I won't bother with a JS sample since it'll likely just cause problems.

You can save this hassle by adding a timestamp as a search param in your JS and CSS links when compiling the HTML.

Answer 6

For angular users and as found here, you can do the following:

<form [action]="myAppURL" method="POST" #refreshForm></form>

import { Component, OnInit, ViewChild } from '@angular/core';

@Component({
  // ...
})
export class FooComponent {
  @ViewChild('refreshForm', { static: false }) refreshForm: ElementRef<HTMLFormElement>;

  forceReload() {
    this.refreshForm.nativeElement.submit();
  }
}

explanation: Angular

Location: reload(), The Location.reload() method reloads the current URL, like the Refresh button. Using only location.reload(); is not a solution if you want to perform a force-reload (as done with e.g. Ctrl + F5) in order to reload all resources from the server and not from the browser cache. The solution to this issue is, to execute a POST request to the current location as this always makes the browser to reload everything.

Not using Angular

Apparently, "Fetching the file by post does clear the cached file and it seems to work in any browser"

So using "he fetch api with POST" should also work

Answer 7

UPDATED to refresh all the external resources (images, JavaScript, CSS, etc.)

Put this in file named HardRefresh.js:

  function hardRefresh() {
    const t = parseInt(Date.now() / 10000); //10s tics
    const x = localStorage.getItem("t");
    localStorage.setItem("t", t);

    if (x != t) location.reload(true) //force page refresh from server
    else { //refreshed from server within 10s
      const a = document.querySelectorAll("a, link, script, img")
      var n = a.length
      while(n--) {
        var tag = a[n]
        var url = new URL(tag.href || tag.src);
        url.searchParams.set('r', t.toString());
        tag.href = url.toString(); //a, link, ...
        tag.src = tag.href; //rerun script, refresh img
      }
    }
  }

  window.addEventListener("DOMContentLoaded", hardRefresh);
  window.addEventListener("deviceorientation", hardRefresh, true);

This code do a fully controled forced hard refresh for every visitor, so that any update will show up without a cashing problem.

Duplicated DOM rendering is not a performance issue, because the first render is from cache and it stops rendering in <script src="js/HardRefresh.js"> where it reload a page from server. When it run a refreshed page it also refresh urls in page.

The last refresh time x is stored in localStorage. It is compared with the current time t to refresh within 10 seconds. Assuming a load from server not take more than 10 sec we manage to stop a page refresh loop, so do not have it less than 10s.

For a visitor of page the x != t is true since long time ago or first visit; that will get page from server. Then diff is less than 10s and x == t, that will make the else part add query strings to href and src having sources to refresh.

The refresh() function can be called by a button or other conditioned ways. Full control is managed by refining exclusion and inclusion of urls in your code.

Answer 8

The most reliable way I've found is to use a chache buster by adding a value to the querystring.

Here's a generic routine that I use:

    function reloadUrl() {

        // cache busting: Reliable but modifies URL
        var queryParams = new URLSearchParams(window.location.search);
        queryParams.set("lr", new Date().getTime());        
        var query = queryParams.toString();                
        window.location.search = query;  // navigates
    }

Calling this will produce something like this:

https://somesite.com/page?lr=1665958485293

after a reload.

This works to force reload every time, but the caveat is that the URL changes. In most applications this won't matter, but if the server relies on specific parameters this can cause potential side effects.

Answer 9

The accepted answer location.reload(true); DOES NOT WORK. Here's why (taken directly from the MDN page):

Note: Firefox supports a non-standard forceGet boolean parameter for location.reload(), to tell Firefox to bypass its cache and force-reload the current document. However, in all other browsers, any parameter you specify in a location.reload() call will be ignored and have no effect of any kind.

You may, though, come across instances of location.reload(true) in existing code that was written with the assumption the force-reload effect occurs in all browsers. A GitHub "location.reload(true)" search returns several hundred thousand results. So there's a lot of existing code which has it.

The history of it is: some version of Netscape Navigator added support for it, which apparently eventually got picked up in Firefox. And at one point the W3C Web APIs Working Group took up an issue to consider adding it to the specification for location.reload(). However, it was never actually added.

So a boolean parameter is not part of the current specification for location.reload() — and in fact has never been part of any specification for location.reload() ever published.

Source: https://developer.mozilla.org/en-US/docs/Web/API/Location/reload

So, how to force a hard refresh? Two ideas:

1. Use query strings, as suggested/explained/demoed in multiple other answers in this thread;

2. Flood the W3C with requests.
   https://www.w3.org/Consortium/contact

(Had suggestion #2 been widely adopted years ago, we could have stopped using the query string hack years ago.)

Answer 10

The location.reload(true) is deprecated so there is no direct option to hard reload but we can still manually clear the cache and then reload. Use this custom function instead.

export const clearCache =  (reloadAfterClear = true) => {
    if('caches' in window){
        caches.keys().then((names) => {
            names.forEach(async (name) => {
                await caches.delete(name)
            })
        })

        if(reloadAfterClear)
            window.location.reload()
    }
}

If you don't want to refresh immidiately and just clear the cache, use clearCache(false)

Hope it helps as none of the above options worked for me.