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SSL Tools

SSL Certificate Checker

See whether a website's HTTPS certificate is valid, trusted by browsers and set up correctly - with every certificate detail in one report.

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Not sure what to enter? Try an example: github.com
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Valid

github.com

Certificate is valid (42 days remaining).

Validation Summary

Certificate Valid Browser Trusted Hostname Matched Chain Complete TLS Supported

Certificate Information

Common Name (CN)
github.com
Subject Alternative Names (SAN)
DNS:github.com, DNS:www.github.com
Organization (O)
—
Organizational Unit (OU)
—
Country
—
State
—
Locality
—

Issuer Information

Issuer Common Name
Sectigo Public Server Authentication CA DV E36
Issuer Organization
Sectigo Limited
Issuer Country
GB

Certificate Details

Certificate Type
Domain Validation (DV)
Certificate Authority
Sectigo Limited
Valid From
Sep 1, 2026
Valid Until
Nov 29, 2026
Remaining Days
42 days
Certificate Status
Active
Signature Algorithm
ecdsa-with-SHA256
Public Key Algorithm
ECDSA
Key Size
256 bits
Serial Number
A59EBDB596751DB7F5C095079613953C
SHA-1 Fingerprint
d3b63e61c64fd29ba9b8729628f8697f556a341f
SHA-256 Fingerprint
46b601ee08b418cf8a3a1ebfe670ba5ce43bb05a917fa8b2dd087a30471cfc63

TLS Information

Supported TLS Version
TLSv1.3
Cipher Suite
TLS_AES_128_GCM_SHA256
Protocol Status
Supported

Server Information

Server IP Address
20.207.73.82
Reverse DNS
—
Server Software
github.com

Certificate Chain

Subject Issuer Valid From Expiry Signature Algorithm
github.com Sectigo Public Server Authentication CA DV E36 Sep 1, 2026 Nov 29, 2026 ecdsa-with-SHA256
Sectigo Public Server Authentication CA DV E36 Sectigo Public Server Authentication Root E46 Mar 22, 2021 Mar 21, 2036 ecdsa-with-SHA384
Sectigo Public Server Authentication Root E46 USERTrust ECC Certification Authority Mar 22, 2021 Jan 18, 2038 ecdsa-with-SHA384
Last checked: 0 seconds ago Live
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100/100

Result Summary

Passed

SSL certificate is valid
Certificate has 42 days remaining
Trusted by browsers (valid chain to a trusted root)
Hostname matches the certificate
Certificate chain is complete
TLS supported (TLSv1.3)

Type a domain to test the certificate its server presents right now. You get a clear verdict first, then the issuer, the names it covers, the chain and the remaining validity.

Recent Searches

SSL Certificate Checker - github.com 0 seconds ago

What does an SSL certificate checker show?

An SSL certificate checker connects to a website over HTTPS and reads the certificate the server presents: who issued it, which domain names it covers, when it became valid and when it expires. It tells you whether visitors will see a secure padlock or a browser warning, without having to open the site in every browser.

How to check a website's SSL certificate

  1. Enter the domain, for example example.com, in the box above.
  2. Click Check SSL.
  3. Confirm the certificate is valid and that the domain you entered is listed among the names it covers.
  4. Look at the expiry date - renew well before it, or make sure automatic renewal is working.
  5. If the issuer is unknown or the certificate is self-signed, install a certificate from a trusted certificate authority.

Related checks

JustChecker monitors your SSL certificates automatically and alerts you before they expire - never lose customer trust to a browser warning again.

Frequently Asked Questions

Your browser may be using a cached connection or a different server than your visitors. This test opens a fresh connection from outside your network and shows exactly what a new visitor receives, including chain problems some browsers quietly work around.

The certificate was issued for different names than the one you entered - for example only www.example.com while visitors open example.com. Reissue the certificate so it lists every name people use, or redirect the uncovered name.

Yes. Let's Encrypt is trusted by every major browser, so a correctly installed free certificate passes this test exactly like a paid one.
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