JavaScript is usually on by default, but you may need to turn it back on if a website stops working

JavaScript is a programming language that makes websites interactive — it powers things like dropdown menus, live search results, video players, and forms that check your answers before you submit them. Most modern browsers turn JavaScript on automatically, but if a site looks broken or won't load properly, JavaScript might be off. The steps to turn it back on differ slightly between browsers, but the process takes less than a minute in any of them.

You'll know JavaScript is the problem if a website loads but buttons don't respond, pages won't scroll smoothly, or you see a message saying "this site requires JavaScript." Turning it on won't slow down your browser or make it less secure — modern JavaScript runs in a sandbox that prevents it from accessing your files or passwords.

Key Takeaways

  • JavaScript is turned on in most browsers by default, so you only need to change it if a specific website stops working.
  • Chrome, Firefox, Safari, and Edge all have JavaScript enabled by default and do not have a simple on/off switch in their main settings.
  • If a website says it needs JavaScript, the fastest fix is to refresh the page or clear your browser cache before looking for settings.
  • Some browser extensions can block JavaScript on specific sites, so check your installed extensions if one website consistently fails to load.
  • Older versions of Internet Explorer had a JavaScript toggle in settings, but modern browsers removed this option because it breaks most websites.

Why modern browsers don't have a JavaScript on/off switch

Chrome, Firefox, Safari, and Edge removed the ability to turn JavaScript off in their main settings years ago. This happened because nearly every website now depends on JavaScript to work at all — turning it off would break shopping carts, email, maps, and most other services. Browser makers decided it was safer to keep JavaScript on and let you block it on a per-site basis if you need to.

If you're using an older version of Internet Explorer, you can still toggle JavaScript in settings, but those versions are no longer supported and have serious security problems. If you're stuck on an old browser, the better move is to update to a current version of Chrome, Firefox, Safari, or Edge.

How to check if JavaScript is on in Chrome

Open Chrome and click the three vertical dots in the top right corner. Go to Settings, then Privacy and security, then Site settings. Look for JavaScript in the list. If it says "Allowed," JavaScript is on. If it says "Blocked," click it and toggle the switch to allow JavaScript.

If you don't see JavaScript listed under Site settings, it means your version of Chrome has JavaScript on by default and no per-site block is active. In that case, refresh the website that wasn't working — it should load now.

How to check if JavaScript is on in Firefox

Firefox does not have a JavaScript toggle in its main settings menu. To check whether JavaScript is blocked on a specific site, type about:config in the address bar and press Enter. You'll see a warning — click "Accept the Risk and Continue." Search for javascript.enabled. If it shows "true," JavaScript is on globally. If it shows "false," click the arrows icon next to it to flip it back to true.

Most Firefox users will never need to visit this page. If a website isn't working, refresh it first or try opening it in a private window, which loads without extensions that might be blocking JavaScript.

How to check if JavaScript is on in Safari

Safari turns JavaScript on by default and does not offer a way to turn it off in settings. If a website says it needs JavaScript, the problem is almost always that the site itself is broken or your internet connection is slow. Try refreshing the page or waiting a few seconds and loading it again.

If you're using Safari on an iPhone or iPad, JavaScript is always on and cannot be changed. The same is true for Safari on Mac — there is no setting to toggle it.

How to check if JavaScript is on in Edge

Open Edge and click the three horizontal dots in the top right corner. Go to Settings, then Privacy, search, and services. Scroll down to Site permissions and click JavaScript. If the toggle is on (blue), JavaScript is allowed. If it's off (gray), click it to turn JavaScript back on.

Edge also lets you block JavaScript on specific sites. If you've blocked it on a site you now want to use, you can remove that block from the same JavaScript settings page by finding the site in the "Block" list and clicking the X next to it.

What to do if a website still won't work after turning JavaScript on

If you've turned JavaScript on and a website still isn't working, the problem is usually not JavaScript itself. Try refreshing the page with Ctrl+R (Windows) or Command+R (Mac). If that doesn't work, clear your browser cache — this removes old versions of the website's files that might be causing conflicts. In most browsers, you can do this by pressing Ctrl+Shift+Delete (Windows) or Command+Shift+Delete (Mac).

If the site still fails to load, try opening it in a private or incognito window. This loads the website without any of your installed extensions, which sometimes block JavaScript even when your browser settings allow it. If the site works in private mode, one of your extensions is the problem — you can find out which one by disabling extensions one at a time and reloading the page.

Browser extensions that block JavaScript

Some security and privacy extensions, like uBlock Origin and NoScript, can block JavaScript on specific websites. If you've installed one of these and a website suddenly stopped working, the extension is likely the cause. Open your extensions menu (usually a puzzle piece icon in the top right), find the extension, and look for a way to allow JavaScript on that site.

Most blocking extensions show a small icon or number on the address bar when they're active on a page. Clicking that icon usually gives you options to allow JavaScript, cookies, or other features just for that site. If you don't recognize an extension that's blocking JavaScript, you can uninstall it by right-clicking it in the extensions menu and selecting "Remove."

Frequently Asked Questions

Is it safe to turn JavaScript on?

Yes. Modern browsers run JavaScript in a protected environment that prevents websites from accessing your files, passwords, or personal information. Turning JavaScript on makes websites work better and doesn't increase your security risk. The real security threat comes from outdated browsers, not from JavaScript itself.

Will turning JavaScript on slow down my browser?

No. JavaScript runs on your computer, not on the website's server, so it doesn't use your internet speed. It may use a small amount of your computer's processing power, but modern browsers are optimized to run JavaScript efficiently. You won't notice a difference in speed.

Why do some websites say they require JavaScript?

Websites display this message when they detect that JavaScript is blocked or not working. It means the site was built to use JavaScript for core features like loading content, handling forms, or displaying images. Without JavaScript, those features won't work, so the site asks you to turn it on.

Can I turn JavaScript off just for one website?

Yes, but only in Chrome and Edge, which have a per-site JavaScript toggle in their Site settings menu. Firefox and Safari don't offer this option. If you want to block JavaScript on specific sites, you can install an extension like uBlock Origin or NoScript, which gives you fine-grained control over which sites can run JavaScript.

What if I'm using an older browser and can't find these settings?

If you're using Internet Explorer or an older version of another browser, update to the latest version of Chrome, Firefox, Safari, or Edge. Older browsers have serious security problems and don't support modern websites. Updating takes a few minutes and solves most JavaScript issues automatically.