SSL Certificate Checker Community
Questions, answers and tips from people who use the SSL Certificate Checker. Check a domain's SSL/TLS certificate, expiry date, issuer and trust status.
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This page shows only real posts from real people, so it starts empty. The guide below has the questions people most often have about the SSL Certificate Checker. Pick one to start a thread, or write your own.
From the tool guide: common questions about SSL Certificate Checker
The items below are not posts by community members. They come from the written guide for this tool and are here to get a conversation started. Use “Ask a follow-up” to open a thread about any of them.
What is an SSL certificate?
A digital document that proves a website's identity and enables an encrypted HTTPS connection. Modern sites use TLS, the successor to SSL.
From the tool guide Ask a follow-upHow do I know if the certificate is valid?
It must be within its dates, cover the domain name, and be issued by an authority browsers trust. This tool checks all three.
From the tool guide Ask a follow-upWhat does “not trusted” mean?
The certificate is self-signed, signed by an unknown authority, or the server did not send the full chain.
From the tool guide Ask a follow-upHow long do certificates last?
Public certificates are now limited to about 13 months, and many (such as Let's Encrypt) last 90 days.
From the tool guide Ask a follow-upCan it check internal servers?
No. Only public internet hosts can be checked.
From the tool guide Ask a follow-upWhich ports can I check?
443 by default; 8443, 465, 993, 995, 636 and 853 are also supported through the API.
From the tool guide Ask a follow-upWhat this tool does
An expired or misconfigured SSL/TLS certificate makes browsers show a scary warning and drives visitors away. This SSL checker connects to any public domain, retrieves its live certificate and shows whether it is valid and trusted, how many days remain until it expires, who issued it, which domain names it covers and which TLS version and cipher the server negotiated.
How to use it, step by step
- Enter the domain name (for example example.com).
- Press Check certificate.
- Read the verdict and days remaining.
- Review the issuer, names covered and TLS details.
Tips from the guide
- Renew at least 14 days before expiry.
- Make sure the certificate covers both example.com and www.example.com.
- Prefer TLS 1.2 or 1.3; disable older protocols.
- Automate renewal with your host or a free CA like Let's Encrypt.
Common mistakes to avoid
- Forgetting a subdomain that has its own certificate.
- Testing only the www or only the non-www version.
- Leaving auto-renewal broken until the certificate expires.
Who uses it
- Website owners and admins. Catch expiring certificates before visitors see warnings.
- Developers and DevOps. Verify a new certificate or chain is installed correctly.
- Security-minded users. Check who vouches for a site.
How to ask a question people can answer
A good thread on the SSL Certificate Checker saves everyone time. Start with a title that names the exact problem, such as the input you used, the result you expected and the result you got. A title like “Not working” is hard to answer, while a title with the specifics gets replies quickly.
- Say what you tried. List the steps you followed and any settings you changed, so replies do not repeat what you already did.
- Share a small example. A short sample input and the output you saw is worth more than a long description. Remove anything private first.
- Mention your setup. Your device, browser and whether you are on a phone or a computer can explain many odd results.
- One question per thread. Separate topics get clearer answers and are easier to find later with the search box above.
- Come back and reply. If a suggestion worked, say so and upvote it, and if you found the fix yourself, post it for the next person.
Community rules
Be kind, stay on topic and keep personal data out of your posts. Do not post adult, hateful or illegal content, advertising or repeated links. Every post is shown with its author’s username and date, and posts that break these rules can be hidden by moderators. This space is for help with the SSL Certificate Checker and related tasks, and it is separate from the sitewide discussion forum where broader topics live.