How to fix “Safari can’t establish a secure connection to the server” (2026 guide)

Nothing kills your workflow faster than seeing the dreaded message: “Safari can’t establish a secure connection to the server.” When this pops up, Safari is blocking a potentially unsafe website to protect your data. But sometimes, it gets a little overzealous and blocks sites you know are safe.

In this guide, I’ll walk you through exactly why Safari throws this error and how to fix it, step by step. I’ll also share a few tools, so you can get back to browsing without the guesswork.

Want a quick fix? Use this Fix My Mac GPT assistant to troubleshoot any Mac problem.

Quick diagnostics: Check your connection and tools

Before you start fixing things, it's helpful to quickly check your network's health. Instead of hunting down separate network analysis tools, apps like WiFi Explorer and NetSpot (both on Setapp) give you everything you need in one place:

• WiFi Explorer: Instantly see real-time stats for your network — signal quality, noise, channel width, and more. It’s great for spotting obvious problems.

• NetSpot: Lets you map your space and find Wi-Fi dead zones. Just walk around with your Mac, and it’ll show you where your signal drops.

With these, you’ll know if your issue is network-related before you start changing settings.

Fixes for “Safari can’t establish a secure connection”

I’ve found that working through these steps usually resolves the Safari connection issue pretty quickly. Most of the time, one of these solutions will get you back to browsing without much hassle.

1. Double-check the URL

This is a small but still important step:

• Make sure you typed the address correctly. Even a small typo can land you on a fake site or trigger security errors.
• If you visit the site often, add it to your bookmarks to avoid mistakes.

2. Set the correct date and time

Incorrect date and time settings can cause SSL certificate verification to fail. I know it sounds random, but I’ve seen this fix work more times than I can count.

To set the date and time:

1. Go to System Settings > General > Date & Time.
2. Turn on Set time and date automatically.
3. Make sure your Mac is set to the correct time zone.

Also, check out how to change time zone on Mac and keep your timetable accurate.

3. Change to a different DNS server

Here’s something that might surprise you: when you type a website address, your computer actually needs to translate that into a numerical address to connect to the site. Sometimes, your ISP’s DNS servers cause problems.

Cloudflare’s DNS is known for privacy and speed. To change to a different DNS server:

1. Go to System Settings > Network.
2. Select your active Wi-Fi connection, then click Details.
3. Go to the DNS tab.
4. Add these addresses:

• 1.1.1.1
• 1.0.0.1
• 2606:4700:4700::1111
• 2606:4700:4700::1001

5. Click OK and Apply.

Changing DNS servers can also improve website loading speed and privacy. If there are DNS issues, use the guide to fix a “service unavailable” DNS failure.

4. Scan for malware and check site safety

Before visiting questionable websites, ensure your Mac has antivirus protection. I use Moonlock (part of Setapp) for this:

1. Install and open Moonlock.
2. Go to the Malware Scanner tab.
3. Click Scan.
4. Remove anything suspicious.

Read also:

• Flush DNS cache on your Mac
• Safari keeps crashing
• Reset network settings on Mac

5. Set the keychain to trust the certificate

If you’re sure a website is safe but Safari keeps blocking it, you can manually trust its SSL certificate. To do so:

1. Go to Finder > Applications > Utilities.
2. Open Keychain Access.
3. Go to the System tab > Click All Items.
4. Find the certificate for the website.
5. Double-click it, expand the Trust section.
6. Set When using this certificate to Always Trust.

Note: Only do this for sites you absolutely trust. Forcing trust in suspicious sites can be risky.

6. Disable IPv6 for your network

IPv6 is a newer version of the internet addressing system that helps devices connect online. While it’s more modern, not all networks, routers, or websites fully support it yet. When IPv6 doesn’t work properly, your Mac may struggle to connect or load pages. Turning it off forces your device to use the older, more widely supported IPv4, which can instantly fix certain connection issues.

To disable it:

1. Go to System Settings > Network.
2. Select your network connection, then Details.
3. Go to the TCP/IP tab.
4. Next to Configure IPv6, select Link-Local Only.

If things improve, you’ve found the culprit.

7. Secure your browsing with a VPN

A VPN encrypts your connection and can help sidestep some network-level security issues. ClearVPN is designed to be straightforward and user-friendly, making it easy to secure your connection even if you’re new to VPNs.

This adds an extra layer of privacy and can resolve some certificate errors.

8. Clear Safari cache and cookies

Old or corrupted cache and cookies can confuse Safari and block secure connections. Here’s how to clear them:

1. Open Safari.
2. Click Safari in the menu bar > Settings > Privacy.
3. Click Manage Website Data…
4. Click Remove All.

9. Disable or remove suspicious Safari extensions

Safari extensions can change how websites load, block scripts, or intercept connections to add extra features. While many are helpful, poorly built or outdated extensions can interfere with secure connections and trigger loading errors.

To check if an extension is causing the problem:

1. Open Safari.
2. Go to the Safari > Settings > Extensions.
3. Deselect or uninstall any extensions you don’t recognize or no longer need.

If the error disappears, you’ve found the problem extension.

10. Update Safari and macOS

Outdated software can cause compatibility issues with secure websites. To update:

1. Go to System Settings > General > Software Update.
2. Install any available updates for macOS and Safari.

Small tip: Turning on automatic updates can help you avoid future issues.

Why Safari says it “can’t establish a secure connection”

Safari throws this error when it can’t verify a site’s SSL certificate or create a secure HTTPS tunnel. In other words, it suspects the connection isn’t safe. This is usually to protect you from data theft, malware, and fraudulent websites. But even legitimate sites can trigger the warning if something’s off with your system or network.

Several common issues cause Safari to block website connections:

• The URL is misspelled (easy to do!)
• Date and time settings are incorrect
• DNS server records might be mixed up
• A malicious script is detected
• An SSL certificate isn’t installed or has expired
• The IPv6 protocol isn’t working correctly
• Out-of-date cache or cookies are confusing Safari
• A browser extension is blocking the secure handshake
• Safari or macOS is out of date

Unsecured websites use http:// before their domain name. Secure sites use https:// and should show a padlock icon in Safari’s address bar. If you see “Not Secure” or the error above, it’s time to investigate.

Tools to analyze and improve your network and fix Safari issues

If Safari can't establish a secure connection on Mac, I rely on a few native methods and curated apps from Setapp that make troubleshooting fast and frustration-free:

• WiFi Explorer: See your network’s health at a glance and fix common Wi-Fi issues.
• NetSpot: Map your space and find Wi-Fi dead zones, so you can reposition your router or add extenders.
• Moonlock: Keep your Mac safe from viruses, detect and remove malware.
• CleanMyMac: Clean up junk, remove malware, and clear browser caches with a click.
• ClearVPN: Encrypt your connection and browse securely, even on public WiFi.

All these apps are available together in Setapp with a seven-day free trial, so you don’t have to waste time searching for the right tool.