Your browser and the server perform a TLS handshake to agree on secret keys, then encrypt all data exchanged so it can't be read or altered in transit.

What does the padlock in the browser mean?

It shows the connection is encrypted with HTTPS and the site presented a valid security certificate.

Is HTTPS completely safe?

It protects data in transit and verifies the site's identity, but it can't guarantee the site itself is trustworthy or malware-free.

Technology

How does HTTPS work?

HTTPS secures the connection between your browser and a website. When you connect, the two sides exchange keys and agree on a shared secret, then encrypt everything sent afterward — so passwords and card numbers travel as scrambled data nobody in between can read.

See it in motion.

Watch a 2-minute animated lesson that shows exactly how HTTPS works.

▶ Watch the visual lesson

Step by step

1It encrypts traffic between your browser and a site.
2A TLS 'handshake' sets up shared secret keys.
3A certificate proves the site is who it claims to be.
4The padlock icon means the page is using HTTPS.

Frequently asked questions

How does HTTPS work?: Your browser and the server perform a TLS handshake to agree on secret keys, then encrypt all data exchanged so it can't be read or altered in transit.
What does the padlock in the browser mean?: It shows the connection is encrypted with HTTPS and the site presented a valid security certificate.
Is HTTPS completely safe?: It protects data in transit and verifies the site's identity, but it can't guarantee the site itself is trustworthy or malware-free.

How does HTTPS work?

Step by step

Frequently asked questions

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