JavaScript is turned off in your browser settings, and you need to turn it back on

JavaScript is a programming language that websites use to make things work — buttons that respond when you click them, forms that check your answers before you submit, videos that play without reloading the page. When JavaScript is off, many websites either look broken or refuse to load at all. The fix depends on which browser you use on your Mac, but the process takes less than a minute in any of them.

Most people have JavaScript on by default and never touch it. If you are reading this, something probably turned it off — either you did it yourself and forgot, or a security tool did it for you. Either way, the steps below will turn it back on.

Key Takeaways

  • JavaScript lives in your browser settings, not in your Mac system settings, so you do not need to restart your computer.
  • Safari, Chrome, and Firefox all have JavaScript on by default, so if a website is broken, JavaScript is usually not the reason.
  • The setting is in a different place in each browser, but you can find it in under a minute once you know where to look.
  • After you turn JavaScript on, close and reopen the website — it will not reload automatically.

How to turn on JavaScript in Safari

Open Safari and click Safari in the menu bar at the top of your screen. Then click Settings (or Preferences if you have an older Mac). A window will open.

Click the Security tab at the top. You will see a checkbox that says Enable JavaScript. If the box is empty, click it to turn JavaScript on. If the box already has a checkmark, JavaScript is already on and something else is the problem. Close the window when you are done.

How to turn on JavaScript in Chrome

Open Chrome and click the three vertical dots in the top right corner. Click Settings. On the left side, click Privacy and security, then click Site settings.

Scroll down and click JavaScript. You will see two options: Allowed and Not allowed. Make sure Allowed is selected (it should have a blue dot next to it). If Not allowed is selected, click Allowed to turn JavaScript on.

How to turn on JavaScript in Firefox

Open Firefox and type about:config in the address bar at the top. Press Enter. A warning page will appear — click Accept the Risk and Continue.

In the search box that appears, type javascript.enabled. You will see one result. Look at the column on the right — if it says false, click the arrows icon on the left side of that row to change it to true. If it already says true, JavaScript is on. Close the tab when you are done.

What to do after you turn JavaScript on

Close the website that was not working, then open it again in a new tab. Do not just refresh the page — close it completely and start fresh. The website should now load properly.

If the website still does not work, JavaScript was probably not the problem. Try clearing your browser cache (the temporary files your browser stores), or try opening the website in a different browser to see if the problem follows you. If it does, the issue is with your internet connection or the website itself, not your Mac.

When you might want JavaScript off

JavaScript is safe on modern websites, and turning it off breaks more things than it protects. The only reason to turn it off is if you are trying to troubleshoot a specific problem — for example, if a website is running slowly or crashing your browser, and you suspect a script is the cause. In that case, turn it off, test the website, and turn it back on when you are done.

If you are worried about privacy or security, JavaScript is not the lever to pull. Use your browser's built-in tracking prevention instead (Safari calls it Intelligent Tracking Prevention, Chrome calls it Privacy Sandbox, and Firefox calls it Enhanced Tracking Protection). These tools block trackers without breaking websites.

Frequently Asked Questions

Why would JavaScript be off if I never turned it off?

Some security software or browser extensions can disable JavaScript as part of their protection settings. Check any security tools you installed recently, or try disabling extensions one at a time to see if one of them is the culprit. Your browser itself almost never turns JavaScript off on its own.

Will turning JavaScript on make my Mac slower?

No. JavaScript runs inside your browser, not on your Mac as a whole. It might make a single website slower if that website has poorly written code, but it will not affect your Mac's overall speed or battery life.

Is JavaScript the same as Java?

No — they are completely different languages with similar names. Java is rarely used on websites anymore. JavaScript is what runs on almost every website you visit. You do not need to worry about Java on your Mac.

What if I turn JavaScript on and a website still does not work?

The problem is something else. Try opening the website in a different browser to see if it works there. If it does, the issue is with your first browser, not your Mac. If it does not work in any browser, the website may be down or your internet connection may be the problem.