Web browsing has become safer since the implementation of HTTPS — a secure version of the HTTP protocol that enables websites to connect to each other and allows us to surf the web. Safari, like other modern browsers, won’t connect to sites that don’t use HTTPS or those with an out-of-date or invalid security certificate. When that happens, you will see an error message saying that Safari could not establish a secure connection. Luckily, you can quickly eliminate it. Keep on reading, and we’ll explain how to fix Safari can’t establish a secure connection.

What does ‘Safari can’t establish a secure connection’ mean?

At its most basic, the error message means that Safari doesn’t trust the website you’re trying to visit. But why can’t Safari establish a secure connection? That could be for one or more of a number of reasons, including:

  • Safari is unable to find the website’s security certificate.
  • The security certificate is out of date.
  • The security certificate is invalid.
  • DNS records are incorrect.
  • Cached data on your Mac is causing Safari to think the website is insecure.
  • There’s another problem with the certificate or website security that leads Safari to conclude it can’t trust it.

The website is there and functioning, and you may be able to access it in another web browser. But Safari has specific security standards that websites need to meet, and if you see that error, it usually means the site doesn’t meet those standards.

However, it’s possible that, in some cases, the problem isn’t with your website and that Safari has got it wrong. We’ll show you below how to check that and fix it if necessary.

Tip

Just like a car or a property, your Mac will last longer and serve you better if you maintain it regularly. Maintenance tasks like reindexing Spotlight or repairing disk permissions are essential. CleanMyMac’s Performance feature automates all of these tasks, also speeding up Mail and freeing up purgeable space. 

CleanMyMac – flush DNS cache

It can even flush your DNS cache, which helps resolve secure connection issues in Safari. You can test CleanMyMac for 7 days at no cost — get your free trial here.

How to fix ‘Safari can’t establish a secure connection’ on Mac?

The first thing to do is to try another web browser. If that browser can connect, the problem could be with Safari, and you might be able to fix it. However, it could also mean that the website meets the security requirements of other browsers, but not Safari. 

If you can’t connect to the website in any browser, there is a problem with the site’s security. That could mean the website is dangerous. If you’re sure it’s safe, you could try contacting the site owner and telling them that it’s inaccessible.

1. Check the web address

Look carefully at the URL of the website you’re trying to visit. Is it correct? One major form of malicious web activity is websites that impersonate other websites using URLs that are very close to the real URL. So, make absolutely sure the URL you have typed or clicked on is correct.

2. Check the date and time on your Mac

If the date and time on your Mac are incorrect, that can cause lots of problems when you try to go online because the time on your Mac won’t match that on the remote server. So, Safari may assume that it indicates a problem with the server. 

  1. Go to System Settings > General > Date and Time and check it’s correct. 
  2. Unless you have a good reason not to, you should turn on Set Time and Date Automatically.
  3. Set the Source to Apple.
macOS Date & Time settings panel with automatic time sync and time zone configuration

3. Clear browser cache

It’s possible that there are cache files on your Mac associated with the site you’re trying to visit that are causing Safari to think that the site is not secure. So, it’s a good idea to clear the cache.

  1. Click the Safari menu and choose Settings.
  2. Choose Privacy.
  3. Click Manage Website Data and wait for it to load.
  4. Click Remove All.
Clearing browser cache

4. Change DNS servers

By default, your Mac uses the DNS server configured by your broadband provider. If the DNS server is down or its records are not up to date, that can cause problems when you try to connect to the internet. And it could make Safari think a site is insecure.

When you type or paste a URL into Safari or any web browser or click on a link, your Mac checks the URL against a Domain Name System (DNS) server and uses that to obtain the IP address of the website so it can connect to it. 

To test this and fix it, switch to a different DNS server. Google has free DNS servers you can use.

  1. Flush your Mac’s DNS cache (see Tip above).
  2. Click the Apple menu and go to System Settings > Wi-Fi.
  3. Choose your Wi-Fi network, then click Details.
  4. In the DNS section, select the current DNS server.
  5. Click the ‘-’ to remove it.
  6. Next, click the ‘+’ to add a new DNS server. Type: 8.8.8.8
  7. Click the ‘+’ again and type: 8.8.4.4
  8. Click OK and quit System Settings.
Changing DNS servers

Your Mac will now use Google’s DNS servers to obtain the IP addresses of websites it needs to connect to. Try to connect to the website again. If it works, you’ll know the problem was with your broadband’s DNS server.

5. Check your browser extensions

If you have lots of extensions installed in Safari, one of those could be causing a problem that leads Safari to think a website is insecure. 

To check whether a browser extension is causing the problem, disable all browser extensions in Safari and try to access the website again.

  1. Click the Safari menu and choose Settings.
  2. Select Extensions in the bar at the top.
  3. Choose each extension in turn and deselect the box next to it.
  4. Quit and reopen Safari and try to go to the website again.
Safari browser extensions

6. Disable antivirus software if you have one

Sometimes, malware cleaners can block safe connections. To rule it out, disable your antivirus software, but only if you are 100% sure that the website you are trying to access is safe.

Find the option to quit your antivirus and try again. If it helps, check the settings to see if you can tweak them and allow accessing this specific website in the future (if you need to, of course). Alternatively, switch to another virus removal tool.

Did you know?

CleanMyMac — the tool we mentioned above — comes with the Protection feature that can detect the latest Mac-specific threats. It also scans your Mac in the background to prevent any malware from sneaking onto your computer.

7. Tell Keychain to trust the website’s security certificate

One of the reasons you will see the ‘Safari can’t establish a secure connection’ error is that there is an issue with the website’s security certificate, which means that Safari can’t read it or thinks it is invalid, perhaps because it’s out of date. 

If you’re sure the site is safe, you can tell Safari to trust the certificate using Keychain Access.

  1. Go to Applications > Utilities and open Keychain Access.
  2. Choose System in the sidebar, then All Items in the toolbar.
  3. Look for the website’s security certificate in the main window. If you can’t find it, try clicking Certificates in the toolbar.
  4. Double-click the certificate.
  5. Click the down arrow next to Trust.
  6. Choose Always Trust from the ‘When using this certificate’ menu.
  7. Quit Keychain Access and try to open the website again.
website’s security certificate

8. Reset Safari

If some of Safari's preferences got corrupted, it may also prevent it from opening legit websites. One solution is to reset Safari.

Resetting an application returns it to the state it was in when you first installed it. In the case of Safari, that means when macOS was first installed on the computer or when an update that included an update to Safari was last installed. To reset an application manually, you would have to remove all the settings and supporting files, as well as user data, that it has placed on your Mac. However, CleanMyMac can do it for you.

  1. In CleanMyMac, click Applications > Scan > Manage My Applications.
  2. Locate Safari in the list of all apps and click an arrow (>) next to it.
  3. Select everything except Binaries.
  4. Click Remove.
Uninstaller module in CleanMyMac

If you don’t see Safari on the list, open CleanMyMac Settings from the menu bar. Go to Ignore List > Uninstaller and deselect Ignore System Applications. Now, follow the steps outlined above to reset Safari.

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  • You can test it for 7 days without any limitations
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  • The winner of the Red Dot Award and the UX Design Awards and Apple notarized — beautifully crafted, user-friendly, and safe to use

Try CleanMyMac for free — see it in action on your MacBook.

Getting this error on an iPhone? 

This error may appear on iPhone/iPad, too. You cannot flush DNS cache on iOS/iPadOS or reset Safari, but you can follow the above steps. 

To change DNS, click an i next to your network in Settings > Wi-Fi, choose Manual in Configure DNS, tap Add Server, and enter your DNS servers. 

Also, delete Safari cache and cookies (this article from Apple has everything you need to know about how to do it) and reset network settings (look for the respective section in this guide on how to reset an iPhone).

Key takeaways

If Safari cannot establish a secure connection to server, it won’t take you to the website because it doesn’t meet Safari’s security standards. You may see this error message on one website only, and not on others. 

First, try opening the website in another browser. If it loads, the problem is Safari-side, so check Safari-related fixes first:  

  • Clear browser cache
  • Remove unneeded browser extensions 
  • Reset Safari

If it does not load, the problem is website- or macOS-related. Try these steps to troubleshoot it: 

  • Double-check the URL
  • Check the time and date
  • Clear DNS cache (using CleanMyMac or manually) and change DNS settings
  • Disable your antivirus
  • Check Keychain to tell Safari to trust the website's security certificate

Frequently asked questions

Can a VPN cause Safari to show this secure connection error?

Yes, VPN interference is a common real-world cause of the error. Try disabling your VPN and check if you can now access the website. 

How do I safely override the warning if I know the website is trustworthy?

To bypass the warning on a trusted site, click Show Details on the error page and select Visit this website. If you cannot see it, you can permanently force Safari to trust it using the Keychain app as shown above. 

Important: Proceed with caution. Bypassing security warnings removes encryption protections, exposing any passwords or credit card information you enter to potential interception.

How do I check whether Safari's date and time settings are causing the error?

Verify your system settings rather than Safari's internal preferences, as Safari relies on your device's system clock to validate a website's SSL certificate. If your system time is significantly off, the certificate may appear expired or not yet valid, triggering the security warning.

What exactly is an SSL/TLS certificate and why does Safari care so much about it?

An SSL/TLS certificate is a digital security file installed on a website's server. It acts as an "electronic passport" that authenticates the website’s identity and enables encrypted HTTPS connections, ensuring cybercriminals cannot intercept or alter the data you send or receive. Safari prioritizes user privacy and security across macOS and iOS, enforcing strict validation rules to protect you from phishing and data theft.