257

I am doing an online quiz application in PHP. I want to restrict the user from going back in an exam.

I have tried the following script, but it stops my timer.

What should I do?

The timer is stored in file cdtimer.js.

<script type="text/javascript"> window.history.forward(); function noBack() { window.history.forward(); } </script> <body onLoad="noBack();" onpageshow="if (event.persisted) noBack();" onUnload=""> 

I have the exam timer which takes a duration for the exam from a MySQL value. The timer starts accordingly, but it stops when I put the code in for disabling the back button. What is my problem?

2

40 Answers 40

209

There are numerous reasons why disabling the back button will not really work. Your best bet is to warn the user:

window.onbeforeunload = function() { return "Your work will be lost."; }; 

This page does list a number of ways you could try to disable the back button, but none are guaranteed:

http://www.irt.org/script/311.htm

Sign up to request clarification or add additional context in comments.

5 Comments

You should check in your PHP code if the answer has been submitted already and if so reject it.
It's worth mentioning that things have now changed in modern browsers: see stackoverflow.com/questions/19926641/…
it works but, This shows the alert on all the menu buttons as well. when it is going to change page, it shows the alert. Can we just fix it to the back button only
This is not fully supported in safari on iOS - developer.mozilla.org/en-US/docs/Web/API/Window/…
non-technical users don't read, they are annoyed. Disabling the back button is the only solution.
173

I came across this, needing a solution which worked correctly and "nicely" on a variety of browsers, including Mobile Safari (iOS 9 at time of posting). None of the solutions were quite right. I offer the following (tested on Internet Explorer 11, Firefox, Chrome, and Safari):

history.pushState(null, document.title, location.href); window.addEventListener('popstate', function (event) { history.pushState(null, document.title, location.href); }); 

Note the following:

  • history.forward() (my old solution) does not work on Mobile Safari --- it seems to do nothing (i.e., the user can still go back). history.pushState() does work on all of them.
  • the third argument to history.pushState() is a url. Solutions which pass a string like 'no-back-button' or 'pagename' seem to work OK, until you then try a Refresh/Reload on the page, at which point a "Page not found" error is generated when the browser tries to locate a page with that as its URL. (The browser is also likely to include that string in the address bar when on the page, which is ugly.) location.href should be used for the URL.
  • the second argument to history.pushState() is a title. Looking around the web most places say it is "not used", and all the solutions here pass null for that. However, in Mobile Safari at least, that puts the page's URL into the history dropdown the user can access. But when it adds an entry for a page visit normally, it puts in its title, which is preferable. So passing document.title for that results in the same behaviour.

16 Comments

This is the correct answer. Works perfectly on Chrome, IE 11, Firefox and Edge.
This should be the accepted answer, it's cross platform and just works fine.
Perfect solution for modern browsers. I have combined with @Rohit416 answer to support older browser just using condition typeof (history.pushState) === "function" work smooth.
In Chrome 79.0.3945.130 this isn't working for me. I implemented exactly as above and I'm able to go back by clicking the Back button. When I hold the Back button and select any item in the history, it's true that I'm blocked. But a quick click on the Back button takes me right back to the previous page.
Doesn't work on Chrome 99 untill I click inside the page(probably activates window.focus()). Works fine on Firefox though. Does anyone have any solution for this ?
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168

It is generally a bad idea overriding the default behavior of the web browser. A client-side script does not have the sufficient privilege to do this for security reasons.

There are a few similar questions asked as well,

You can-not actually disable the browser back button. However, you can do magic using your logic to prevent the user from navigating back which will create an impression like it is disabled. Here is how - check out the following snippet.

(function (global) { if(typeof (global) === "undefined") { throw new Error("window is undefined"); } var _hash = "!"; var noBackPlease = function () { global.location.href += "#"; // Making sure we have the fruit available for juice (^__^) global.setTimeout(function () { global.location.href += "!"; }, 50); }; global.onhashchange = function () { if (global.location.hash !== _hash) { global.location.hash = _hash; } }; global.onload = function () { noBackPlease(); // Disables backspace on page except on input fields and textarea.. document.body.onkeydown = function (e) { var elm = e.target.nodeName.toLowerCase(); if (e.which === 8 && (elm !== 'input' && elm !== 'textarea')) { e.preventDefault(); } // Stopping the event bubbling up the DOM tree... e.stopPropagation(); }; } })(window); 

This is in pure JavaScript, so it would work in most of the browsers. It would also disable the backspace key, but that key will work normally inside input fields and textarea.

Recommended Setup:

Place this snippet in a separate script and include it on a page where you want this behavior. In the current setup it will execute the onload event of the DOM which is the ideal entry point for this code.

Working DEMO!

It was tested and verified in the following browsers,

  • Chrome.
  • Firefox.
  • Internet Explorer (8-11) and Edge.
  • Safari.

12 Comments

I don't understand why the setTimeout. If I just initially append #! to location and remove the setTimeout, it still work.
I created a .js file as recommended and included the js file in my code using the following: <script src="./javascript/noback.js"></script> But I can still perform a back (using Safari). What am I missing? This library was added in the same fashion as other libraries I use, so the include is good.
Blocks back button on ipad air, ios 8
@rohit416. Just tested. The demo is: - Not working with google 87.0.4280.66 - Not working with edge 87.0.664.47 - Still working with ff 83.0. On the two first ones, it works only if the user takes an action on the page (like a click) before deciding to hit the back button. If the user take no action, the script does not work.
Works on Chrome 87.0.4280.141 on Desktop, but not on Android.
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82
<script> window.location.hash = "no-back-button"; // Again because Google Chrome doesn't insert // the first hash into the history window.location.hash = "Again-No-back-button"; window.onhashchange = function(){ window.location.hash = "no-back-button"; } </script> 

9 Comments

Genius! I used this to prevent accidental trigger of Back button when user hits Backspace (on disabled/readonly fields, for example) in a web app where back/forward didn't really make sense anyway. Confirmed disables back and forward functionality (tho not the buttons themselves), including context menu option; verified in IE8 thru IE11, Chrome & FF.
This works, but resets all data entered in textboxes. Is it possible to prevent clearing?
It worked for me on firefox, but not on chrome (version 36.0.1985.143)
This worked for me also, but on Firefox it seems to break the window.history.back() function. We want to prevent the users clicking on the browser back button, but in some cases we provide our own back button on the page. Is there any way to make it work?
This doesn't work for me. I'm using Chrome version 55 on Windows 10. I put the script in several places (start of header, end of body, etc.) and I can still use the back button to go back to the previous page.
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46

For restricting the browser back event:

window.history.pushState(null, "", window.location.href); window.onpopstate = function () { window.history.pushState(null, "", window.location.href); }; 

4 Comments

This works great on chrome!, why people are not voting as this is the best answer?
i just tested it using Windows 10 OS on the following browsers ( works great ) Chrome Version 74.0.3729.108 (Official Build) (64-bit) Chrome Canary Version 76.0.3780.0 (Official Build) canary (32-bit) Chromium Version 66.0.3355.0 (Developer Build) (64-bit) Firefox 66.0.3 (64-bit) EDGE IE 11 Safari 5.1.7
@TarıkSeyceri because this only works on browsers that a) support the history API b) the page is actually using the history API to manage state
Not working anymore in Chrome after Version 75. See: support.google.com/chrome/thread/8721521?hl=en
39

How to block coming backwards functionality:

history.pushState(null, null, location.href); window.onpopstate = function () { history.go(1); };

4 Comments

While this may be a valid answer, you are much more likely to help others by explaining what the code does and how it works. Code-only answers tend to receive less positive attention and aren't as useful as other answers.
Tested on Chrome, Firefox, IE and Edge. It works well. You saved me.
Tested on Chrome 91 and it works perfectly. It'll be better if you explain what happened here as mentioned by @Aurora0001 . Good answer getting low vote.
You can find an explanation of this snippet here: medium.com/codex/…
32

This code will disable the back button for modern browsers which support the HTML5 History API. Under normal circumstances, pushing the back button goes back one step, to the previous page. If you use history.pushState(), you start adding extra sub-steps to the current page. The way it works is, if you were to use history.pushState() three times, then start pushing the back button, the first three times it would navigate back in these sub-steps, and then the fourth time it would go back to the previous page.

If you combine this behaviour with an event listener on the popstate event, you can essentially set up an infinite loop of sub-states. So, you load the page, push a sub-state, then hit the back button, which pops a sub-state and also pushes another one, so if you push the back button again it will never run out of sub-states to push. If you feel that it's necessary to disable the back button, this will get you there.

history.pushState(null, null, 'no-back-button'); window.addEventListener('popstate', function(event) { history.pushState(null, null, 'no-back-button'); }); 

6 Comments

On any browser, try a page Refresh/Reload after this, and you'll get stuck on a "Page not found" error, as it tries to find a page named no-back-button... (The browser is also likely to show no-back-button in the address bar too, which seems ugly.) To be fair, this is not the only solution here which suffers from this. The 3rd argument to history.pushState() is a url, and must be the url of your current page: use location.href instead.
This worked for me. Just change 'no-back-button' to "window.top.location.pathname + window.top.location.search" and it will stay the name of the page you are on, even in refresh
Among others, this worked for me, upvote. Refer to stackoverflow.com/questions/19926641/….
I've explored many cases, and this is the best solution for 1-page site
This is a very bad solution because you're changing the URL, so if you hit back and forwards a few times chrome will redirect to a path that doesn't exist
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22

None of the most-upvoted answers worked for me in Chrome 79. It looks like Chrome changed its behavior with respect to the Back button after version 75. See here:

https://support.google.com/chrome/thread/8721521?hl=en

However, in that Google thread, the answer provided by Azrulmukmin Azmi at the very end did work. This is his solution.

<script> history.pushState(null, document.title, location.href); history.back(); history.forward(); window.onpopstate = function () { history.go(1); }; </script> 

The problem with Chrome is that it doesn't trigger onpopstate event unless you make browser action ( i.e. call history.back). That's why I've added those to script.

I don't entirely understand what he wrote, but apparently an additional history.back() / history.forward() is now required for blocking Back in Chrome 75+.

6 Comments

After searching high & low this finally worked on Android browsers as well, where for some reason the browser's back button event wasn't detected with any other scripts I tried. Thank you, thank you, thank you again! Tested and working fine under Chrome 83 both desktop and mobile! Gene, you're a lifesaver!
Works even if user has not clicked anywhere in the page. Thanks!
Thank you so much! This works in any browsers as well in mobile browsers! Worked like charm. Keep it up! :)
Still work fine, but after I have upgraded my browser to version 87.0.4280.66 (Official Build) (64-bit), it not work. Any work around for it?
For some reason it did not work for me if the page had been loaded and no navigation had happened (still on landing page, on Android/chrome 89). What I did was do a redirect to a different URL on the landing URL. If the user clicks on back on that first page, then a reload happens, but at least I am still on my site. If back is clicked after any navigation, then there is indeed no action taken, no artifacts.
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18

React

For modal component in React project, the open or close of the modal, controlling browser back is a necessary action.

  • The stopBrowserBack: the stop of the browser back button functionality, also get a callback function. This callback function is what you want to do:

    const stopBrowserBack = callback => { window.history.pushState(null, "", window.location.href); window.onpopstate = () => { window.history.pushState(null, "", window.location.href); callback(); }; }; 
  • The startBrowserBack: the revival of the browser back button functionality:

    const startBrowserBack = () => { window.onpopstate = undefined; window.history.back(); }; 

The usage in your project:

handleOpenModal = () => this.setState( { modalOpen: true }, () => stopBrowserBack(this.handleCloseModal) ); handleCloseModal = () => this.setState( { modalOpen: false }, startBrowserBack ); 

Comments

14

This is the way I could it accomplish it.

Weirdly, changing window.location didn't work out fine in Google Chrome and Safari.

It happens that location.hash doesn't create an entry in the history for Chrome and Safari. So you will have to use the pushstate.

This is working for me in all browsers.

history.pushState({ page: 1 }, "title 1", "#nbb"); window.onhashchange = function (event) { window.location.hash = "nbb"; }; 

4 Comments

That does not work in IE9 and below, pushState is not supported.
Great. This is a good approach and works in almost all latest browsers.
Works great in later IE's. Just put directly in the document.ready: $(document).ready(function () { .... });
Keep in mind that you must add your current uri before "#nbb". i.e. "account#nbb"
11
history.pushState(null, null, document.URL); window.addEventListener('popstate', function () { history.pushState(null, null, document.URL); }); 

This JavaScript code does not allow any user to go back (works in Chrome, Firefox, Internet Explorer, and Edge).

Comments

10

This article on jordanhollinger.com is the best option I feel. Similar to Razor's answer but a bit clearer. Code below; full credits to Jordan Hollinger:

Page before:

<a href="/page-of-no-return.htm#no-back>You can't go back from the next page</a> 

Page of no return's JavaScript:

// It works without the History API, but will clutter up the history var history_api = typeof history.pushState !== 'undefined' // The previous page asks that it not be returned to if ( location.hash == '#no-back' ) { // Push "#no-back" onto the history, making it the most recent "page" if ( history_api ) history.pushState(null, '', '#stay') else location.hash = '#stay' // When the back button is pressed, it will harmlessly change the url // hash from "#stay" to "#no-back", which triggers this function window.onhashchange = function() { // User tried to go back; warn user, rinse and repeat if ( location.hash == '#no-back' ) { alert("You shall not pass!") if ( history_api ) history.pushState(null, '', '#stay') else location.hash = '#stay' } } } 

2 Comments

There isn't any current user by the name "Razor". Which answer is referred to?
I think this is a better answer in 2022. Easier to understand and less code. If you are using SSR, you will need to add a check for typeof window !== 'undefined' to avoid issues on the server.
10
<html> <head> <title>Disable Back Button in Browser - Online Demo</title> <style type="text/css"> body, input { font-family: Calibri, Arial; } </style> <script type="text/javascript"> window.history.forward(); function noBack() { window.history.forward(); } </script> </head> <body onload="noBack();" onpageshow="if (event.persisted) noBack();" onunload=""> <H2>Demo</H2> <p>This page contains the code to avoid Back button.</p> <p>Click here to Goto <a href="noback.html">NoBack Page</a></p> </body> </html> 

2 Comments

Is there some documentation somewhere for event.persisted?
Here is the link found for your question. Find it here @Muhd
9

This code was tested with the latest Chrome and Firefox browsers.

<script type="text/javascript"> history.pushState(null, null, location.href); history.back(); history.forward(); window.onpopstate = function () { history.go(1); }; </script> 

2 Comments

Welcome huyhoang.
Works great in Chrome 85 and Safari 14
5

Try it with ease:

history.pushState(null, null, document.title); window.addEventListener('popstate', function () { history.pushState(null, null, document.title); }); 

Comments

4

You can just put a small script and then check. It won't allow you to visit previous page.

This is done in JavaScript.

<script type="text/javascript"> function preventbackbutton() { window.history.forward(); } setTimeout("preventbackbutton()", 0); window.onunload = function () { null }; </script> 

The window.onunload function fires when you try to visit back or previous page through browser.

1 Comment

the is the best working method above all. +1
3

Very simple and clean function to break the back arrow without interfering with the page afterward.

Benefits:

  • Loads instantaneously and restores original hash, so the user isn't distracted by URL visibly changing.
  • The user can still exit by pressing back 10 times (that's a good thing), but not accidentally
  • No user interference like other solutions using onbeforeunload
  • It only runs once and doesn't interfere with further hash manipulations in case you use that to track state
  • Restores original hash, so almost invisible.
  • Uses setInterval, so it doesn't break slow browsers and always works.
  • Pure JavaScript, does not require HTML5 history, works everywhere.
  • Unobtrusive, simple, and plays well with other code.
  • Does not use unbeforeunload which interrupts user with modal dialog.
  • It just works without fuss.

Note: some of the other solutions use onbeforeunload. Please do not use onbeforeunload for this purpose, which pops up a dialog whenever users try to close the window, hit backarrow, etc. Modals like onbeforeunload are usually only appropriate in rare circumstances, such as when they've actually made changes on screen and haven't saved them, not for this purpose.

How It Works

  1. Executes on page load
  2. Saves your original hash (if one is in the URL).
  3. Sequentially appends #/noop/{1..10} to the hash
  4. Restores the original hash

That's it. No further messing around, no background event monitoring, nothing else.

Use It In One Second

To deploy, just add this anywhere on your page or in your JavaScript code:

<script> /* Break back button */ window.onload = function(){ var i = 0; var previous_hash = window.location.hash; var x = setInterval(function(){ i++; window.location.hash = "/noop/" + i; if (i==10){ clearInterval(x); window.location.hash = previous_hash; } }, 10); } </script> 

Comments

2

In a modern browser this seems to work:

// https://developer.mozilla.org/en-US/docs/Web/API/History_API let popHandler = () => { if (confirm('Go back?')) { window.history.back() } else { window.history.forward() setTimeout(() => { window.addEventListener('popstate', popHandler, {once: true}) }, 50) // delay needed since the above is an async operation for some reason } } window.addEventListener('popstate', popHandler, {once: true}) window.history.pushState(null,null,null) 

Comments

2

I had this problem with React (class component).

And I solved it easily:

componentDidMount() { window.addEventListener("popstate", e => { this.props.history.goForward(); } } 

I've used HashRouter from react-router-dom.

Comments

2

You simply cannot and should not do this. However, this might be helpful:

<script type = "text/javascript" > history.pushState(null, null, 'pagename'); window.addEventListener('popstate', function(event) { history.pushState(null, null, 'pagename'); }); </script> 

This works in my Google Chrome and Firefox.

Comments

2

This seems to have worked for us in disabling the back button on the browser, as well as the backspace button taking you back.

history.pushState(null, null, $(location).attr('href')); window.addEventListener('popstate', function () { history.pushState(null, null, $(location).attr('href')); }); 

Comments

2

Just run code snippet right away and try going back

history.pushState(null, null, window.location.href); history.back(); window.onpopstate = () => history.forward();

1 Comment

it does not work on the chrome version 91
2

Try with this: Suppose there are two pages Page1 and Page2 and Page1 redirects to Page2

to prevent user from visiting Page1 using the back button you will need to place the above script in the Page1

$(document).ready(async function (){ history.pushState(null, null, location.href); window.onpopstate = function () { history.go(1); }; }) 

Comments

1
<script src="~/main.js" type="text/javascript"></script> <script type="text/javascript"> window.history.forward(); function noBack() { window.history.forward(); } </script> 

Comments

1

Try this to prevent the backspace button in Internet Explorer which by default acts as "Back":

<script language="JavaScript"> $(document).ready(function() { $(document).unbind('keydown').bind('keydown', function (event) { var doPrevent = false; if (event.keyCode === 8 ) { var d = event.srcElement || event.target; if ((d.tagName.toUpperCase() === 'INPUT' && ( d.type.toUpperCase() === 'TEXT' || d.type.toUpperCase() === 'PASSWORD' || d.type.toUpperCase() === 'FILE' || d.type.toUpperCase() === 'EMAIL' || d.type.toUpperCase() === 'SEARCH' || d.type.toUpperCase() === 'DATE' ) ) || d.tagName.toUpperCase() === 'TEXTAREA') { doPrevent = d.readOnly || d.disabled; } else { doPrevent = true; } } if (doPrevent) { event.preventDefault(); } try { document.addEventListener('keydown', function (e) { if ((e.keyCode === 13)) { //alert('Enter keydown'); e.stopPropagation(); e.preventDefault(); } }, true); } catch (err) { } }); }); </script> 

Comments

1

It's basically assigning the window's "onbeforeunload" event along with the ongoing document 'mouseenter' / 'mouseleave' events so the alert only triggers when clicks are outside the document scope (which then could be either the back or forward button of the browser)

 $(document).on('mouseenter', function(e) { window.onbeforeunload = null; } ); $(document).on('mouseleave', function(e) { window.onbeforeunload = function() { return "You work will be lost."; }; } );

Comments

1

Having gone through most of the existing answers, there is no solution that works in chrome.

The idea is make the browser to move forward one page in the session history, effectively preventing leaving this page using the back browser button. You do this by invoking the History.forward() method, by placing the following line in the page.

window.history.forward(); 

I found this solution at mdn web docs and it works in chrome.

Comments

0

Just set location.hash="Something". On pressing the back button, the hash will get removed from the URL, but the page won't go back.

This method is good for preventing going back accidentally, but for security purposes you should design your backend for preventing reanswering.

Comments

0

Some of the solutions here will not prevent a back event from occurring - they let a back event happen (and data held about the page in the browsers memory is lost) and then they play a forward event to try and hide the fact that a back event just happened. Which is unsuccessful if the page held transient state.

I wrote this solution for React (when react router is not being used), which is based on vrfvr's answer.

It will truly stop the back button from doing anything unless the user confirms a popup:

 const onHashChange = useCallback(() => { const confirm = window.confirm( 'Warning - going back will cause you to loose unsaved data. Really go back?', ); window.removeEventListener('hashchange', onHashChange); if (confirm) { setTimeout(() => { window.history.go(-1); }, 1); } else { window.location.hash = 'no-back'; setTimeout(() => { window.addEventListener('hashchange', onHashChange); }, 1); } }, []); useEffect(() => { window.location.hash = 'no-back'; setTimeout(() => { window.addEventListener('hashchange', onHashChange); }, 1); return () => { window.removeEventListener('hashchange', onHashChange); }; }, []); 

Comments

0

I create one HTML page (index.html). I also create a one (mechanism.js) inside a script folder / directory. Then, I lay all my content inside of (index.html) using form, table, span, and div tags as needed. Now, here's the trick that will make back / forward do nothing!

First, the fact that you have only one page! Second, the use of JavaScript with span / div tags to hide and display content on the same page when needed via regular links!

Inside 'index.html':

<td width="89px" align="right" valign="top" style="letter-spacing:1px;"> <small> <b> <a href="#" class="traff" onClick="DisplayInTrafficTable();">IN</a>&nbsp; </b> </small> [&nbsp;<span id="inCountSPN">0</span>&nbsp;] </td> 

Inside 'mechanism.js':

function DisplayInTrafficTable() { var itmsCNT = 0; var dsplyIn = ""; for (i=0; i<inTraffic.length; i++) { dsplyIn += "<tr><td width='11'></td><td align='right'>" + (++itmsCNT) + "</td><td width='11'></td><td><b>" + inTraffic[i] + "</b></td><td width='11'></td><td>" + entryTimeArray[i] + "</td><td width='11'></td><td>" + entryDateArray[i] + "</td><td width='11'></td></tr>"; } document.getElementById('inOutSPN').innerHTML = "" + "<table border='0' style='background:#fff;'><tr><th colspan='21' style='background:#feb;padding:11px;'><h3 style='margin-bottom:-1px;'>INCOMING TRAFFIC REPORT</h3>" + DateStamp() + "&nbsp;&nbsp;-&nbsp;&nbsp;<small><a href='#' style='letter-spacing:1px;' onclick='OpenPrintableIn();'>PRINT</a></small></th></tr><tr style='background:#eee;'><td></td><td><b>###</b></td><td></td><td><b>ID #</b></td><td></td><td width='79'><b>TYPE</b></td><td></td><td><b>FIRST</b></td><td></td><td><b>LAST</b></td><td></td><td><b>PLATE #</b></td><td></td><td><b>COMPANY</b></td><td></td><td><b>TIME</b></td><td></td><td><b>DATE</b></td><td></td><td><b>IN / OUT</b></td><td></td></tr>" + dsplyIn.toUpperCase() + "</table>" + ""; return document.getElementById('inOutSPN').innerHTML; } 

It looks hairy, but note the function names and calls, embedded HTML, and the span tag id calls. This was to show how you can inject different HTML into same span tag on same page! How can Back/Forward affect this design? It cannot, because you are hiding objects and replacing others all on the same page!

How can we hide and display? Here goes:

Inside functions in ' mechanism.js ' as needed, use:

document.getElementById('textOverPic').style.display = "none"; //hide document.getElementById('textOverPic').style.display = ""; //display 

Inside ' index.html ' call functions through links:

<img src="images/someimage.jpg" alt="" /> <span class="textOverPic" id="textOverPic"></span> 

and

<a href="#" style="color:#119;font-size:11px;text-decoration:none;letter-spacing:1px;" onclick="HiddenTextsManager(1);">Introduction</a> 

Comments

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