How to Fix the Mozilla Firefox for Windows ‘Performing a TLS Handshake’ Error?

How to Fix the Mozilla Firefox for Windows 'Performing a TLS Handshake' Error?

Here we can see, “How to Fix the Mozilla Firefox for Windows ‘Performing a TLS Handshake’ Error?”

The “Performing a TLS Handshake” notice is an error message that shows while trying to load some websites using Mozilla Firefox for Windows.

A TLS handshake is a secure data exchange between your browser and the website you’re trying to connect to. It’s utilized by HTTPS, and therefore you’ll likely see it while connecting to an HTTPS site. Resolving this issue shouldn’t be too tough as people have come up with numerous solutions. We’ve compiled these methods into one article, so read on!

Why does Firefox for Windows fail to perform a TLS handshake?

Several factors can cause your browser to stall during the TLS handshake. Check out our list of possible causes below!

  • Recent add-ons: Recent extensions and plugins may create this issue. An addon doesn’t have to be malicious to cause this issue, but it should be uninstalled if found.
  • Its HTTP(S) checking functions enable additional checks and inspections beyond those performed when you open a website. Due to this, we recommend disabling these features in your browser.
  • IPv6 and DNS: Some users have reported issues with IPv6 connectivity or DNS address. In that case, disabling IPv6 and changing your DNS address should suffice.
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Solution 1: Disable Recent Suspicions Addons

Recent changes to your Mozilla Firefox browser may have produced connection issues that prevent you from being confirmed during a TLS handshake. Remove any suspicious add-ons you may have recently installed.

  1. Double-click the Mozilla Firefox icon on the Desktop or search for it in the Start menu.
  2. Click on the Menu icon in the top right corner of the browser and select Add-Ons.
  3. Locate and select the Plugins option in the right pane of the screen to see all installed plugins. Click the three dots next to the plugin you want to uninstall.
  4. Select Remove from the context menu and confirm the deletion. If the message Restart now appears, click it. Re-run the process, but this time select Extensions or Themes.
  5. Restart your browser to see if the issue is resolved.

Solution 2: Use DNS Google

Users have reported that they could fix the issue by using Google‘s free DNS instead of their ISP’s. DNS issues can delay the TLS handshake. Change your computer’s DNS address by following the steps below!

  1. To open the Internet Connection Settings item in Control Panel, press Windows + R to open the Run dialogue box. Type’ ncpa.cpl’ in the text field and click OK.
  2. Alternatively, open Control Panel manually. Change the View by option in the window’s top right to Category and select Network & Internet. Open the Network and Sharing Center by clicking the button on the left menu.
  3. Once the Internet Connection box is up, double-click on your active network adapter (connection to the Internet) and select Properties if you have admin capabilities.
  4. Locate the TCP/IPv4 entry on the list. Click it to pick it and then click the Properties option.
  5. Then, change the radio button to “Use the following DNS server addresses” if it wasn’t already in the Properties window.
  6. The alternate DNS server is
  7. Keep “Validate settings upon exit” checked and click OK to save the changes. Check if “Performing a TLS Handshake” still hangs in Firefox!

Solution 3: Remove HTTP/Port Checking from Antiviruses

Because your antivirus is analyzing the site’s certificates, it slows down the process of requesting files from the servers, causing the “Performing a TLS Handshake” message to hang in Mozilla Firefox.

Following are instructions on discovering HTTP or Port scanning settings in various common third-party AV programs that produce this problem.

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  1. Double-click the antivirus icon in the system tray (bottom right of the window) or search for it in the Start menu.
  2. The HTTPS scanning option varies amongst antivirus software. However, here are some simple recommendations on how to find it in the most major antivirus tools:
Kaspersky Internet Security: Home >> Settings >> Additional >> Network >> Encrypted connections scanning >> Do not scan encrypted connections
AVG: Home >> Settings >> Components >> Online Shield >> Enable HTTPS Scanning (uncheck it)
Avast: Home >> Settings >> Components >> Web Shield >> Enable HTTPS Scanning (uncheck it)
ESET: Home >> Tools >> Advanced Setup >> Web and Email >> Enable SSL/TLS protocol filtering (turn it off)

Check if you can now download the file without getting the “Performing a TLS Handshake” warning! Try a different antivirus or firewall if the error persists, especially if the current one is free!

Solution 4: Disable IPv6

Many consumers reported success disabling Internet Protocol version 6 connectivity on their computers, and it is a simple solution. This makes this strategy worthwhile, and you should use it when troubleshooting.

  1. Type’ ncpa.cpl’ in the bar and click OK to open the Internet Connection settings item in Control Panel.
  2. Alternatively, open the Control Panel manually. Change the View by clicking on Network and Internet in the top right corner of the window. To open it, click the Network and Sharing Center button. Locate and click the Change adapter settings button on the left menu.
  3. Double-click your active Network Adapter in the Internet Connection panel.
  4. Then select Properties and look for IPv6 in the list. Disable the checkbox and click OK. Restart your computer to verify the modifications and see if the issue persists.

User Questions:

To fix TLS handshake in Firefox

  1. Click Options on the Firefox menu.
  2. Go to Advanced > Encryption.
  3. Uncheck Use TLS 1.0 and SSL 3.0.
  4. Press OK.
  5. Reopen Firefox.

How to repair TLS handshake?

by August 2020.) A client-side issue might cause the SSL/TLS handshake to fail in some situations. Some may seem trivial, like updating your browser or ensuring your system time is right.


The problem is usually caused by your antivirus analyzing the sites’ certificates, which slows down the process of requesting data from servers, causing the “Performing a TLS Handshake” message to linger in Mozilla Firefox.

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What does a TLS handshake imply?

A TLS handshake initiates a TLS-encrypted communication session. During a TLS handshake, the two communicating parties exchange messages to acknowledge, verify, agree on encryption techniques, and exchange session keys.

How do I configure TLS in Firefox?

  1. Firefox.
  2. Type about:config and hit Enter.
  3. To search, type tls. To secure the entry, double-click it. tls.version.min.
  4. Set the integer value to 3 to make TLS 1.2 the default protocol.
  5. OK.
  6. Restart Mozilla Firefox after closing it.