SSL Checker - Check SSL Certificate Expiry and Issuer
Enter a website to see who issued its SSL certificate, when it started, when it expires and how many days are left. A green badge shows a valid certificate and a red warning shows an expired or invalid one. Free, no signup.
The certificate details are fetched by a third-party service, so the domain you enter is sent to that service. Do not enter private or internal addresses.
SSL Certificate Checker
Issuer • Valid Till • Days Left🔍 You Can Also Visit More Tools Categories
What is an SSL Checker?
An SSL checker looks at the SSL certificate of a website and shows its main details. The certificate is what lets your browser connect to a website over HTTPS, with the lock icon and an encrypted connection. Every certificate has an issuer and a validity period. When the validity period ends, the certificate expires and browsers warn visitors that the site is not safe to open.
This tool shows the four things that matter most for a quick check: who issued the certificate, when it became valid, when it stops being valid and how many days remain.
How to Check an SSL Certificate
- Type a domain, such as
google.com, or a full address, such ashttps://example.com. - Click Check SSL and wait for the result. The check is done by an outside service, so it can take a little time.
- Read the Issuer, Valid From, Valid Until and Days Remaining.
- Look for the green Secure badge or the red warning.
- Click Copy Result to copy the details, or Check Again to run the check once more.
Type only the website name. You do not need to add a page path, and you do not need to type the port.
What You See on the Page
| Item | Meaning |
|---|---|
| Issuer | The certificate authority that issued the certificate, for example Let's Encrypt or Google Trust Services |
| Valid From | The date and time when the certificate started to be valid |
| Valid Until | The date and time when the certificate stops being valid |
| Days Remaining | How many days are left until the Valid Until date |
| Green Secure badge | The certificate is within its validity dates and was reported as valid |
| Red warning | The certificate is expired or invalid, or has a problem |
| Copy Result and Check Again | Copy the details, or run the check once more |
What Secure Does and Does Not Mean
| The green badge means | The green badge does not mean |
|---|---|
| The certificate is currently inside its validity dates | That the website is honest or trustworthy |
| The checker reported the certificate as valid | That the website is free from malware or scams |
| The connection can be encrypted | That the server has no other security problems |
Scam and phishing websites can also have valid certificates. A valid certificate only shows that the connection is encrypted and that the site proved it controls its domain name.
Days Remaining Explained
Days Remaining is the difference between today and the Valid Until date. An example, with made-up dates:
| Today | Valid Until | Days Remaining |
|---|---|---|
| 1 December | 31 December | 30 days |
| 15 March | 14 April | 30 days |
| 10 June | 9 June (same year) | Expired |
Certificate dates are stored in UTC, which is the world time standard. Because of this, the exact moment of expiry can fall on a different calendar day in your own time zone. For example, a certificate that ends late in the evening in UTC ends the next morning in India Standard Time (UTC+5:30).
Why SSL Certificates Expire
Certificates are given a limited lifetime on purpose. A short lifetime limits the time a stolen or wrong certificate can be misused, and it forces websites to keep their security up to date. The maximum lifetime that certificate authorities may give has been getting shorter over the years, so expiry dates come around more often than before. Many free certificates are valid for around three months, and many hosts renew them automatically. Check your provider for the exact period that applies to you.
What Happens When a Certificate Expires?
- Browser warning: Visitors see a full-page message that the connection is not private, and many of them leave.
- Lost trust and sales: People do not enter their details or pay on a site that shows a warning.
- Broken apps and APIs: Mobile apps, payment flows, webhooks and other services that connect to your site can stop working.
- Search visibility: A site that is not reachable over HTTPS can lose visitors and may be seen as lower quality.
The fix is to renew or replace the certificate and install it on the server. Your hosting provider or certificate authority can tell you how.
Why You Might See a Red Warning
| Problem | What it means | What to check |
|---|---|---|
| Expired | The Valid Until date has passed | Renew the certificate and install it |
| Not yet valid | The Valid From date is in the future | Check the certificate dates and the clock of the server |
| Name mismatch | The certificate was issued for a different name, for example only for example.com but not www.example.com | Get a certificate that covers every name you use |
| Self-signed | The certificate was signed by the site itself and not by a trusted authority | Use a certificate from a trusted certificate authority |
| Untrusted issuer | The authority that signed it is not trusted by browsers | Use a certificate from a widely trusted authority |
| Incomplete chain | The server did not send the intermediate certificates | Install the full chain, as given by your certificate authority |
The checker shows that there is a problem. It does not always list every reason, so look at your server and certificate setup if you see a warning.
SSL vs TLS
| Term | What it is |
|---|---|
| SSL | The older security protocol. The old versions are no longer considered safe and are switched off on modern servers |
| TLS | The newer and more secure protocol that is used today |
| SSL certificate | The everyday name for the certificate used by HTTPS. It works with TLS |
| HTTPS | HTTP carried over an encrypted TLS connection |
Common Certificate Authorities
The issuer shows which certificate authority signed the certificate. You may see names such as these:
| Issuer name | Note |
|---|---|
| Let's Encrypt | A free, automated authority that is widely used |
| Google Trust Services | The authority run by Google, used for many Google services |
| DigiCert | A commercial authority |
| Sectigo | A commercial authority |
| GlobalSign | A commercial authority |
| Amazon | Certificates issued through Amazon's certificate services |
The issuer name only tells you who signed the certificate. It is not a ranking of quality, and many different authorities are fully trusted by browsers.
Tips to Avoid an Expired Certificate
- Turn on automatic renewal at your host or certificate authority if it is available.
- Check that renewal really works. Automatic renewal can fail quietly, for example after a server change.
- Renew early. Do not wait for the last days. A few weeks of margin gives time to fix problems.
- Check every name you use, including the www version and any subdomains.
- Write the expiry date in your calendar if you renew by hand, and tell more than one person.
- Use a real email address for your account with the authority, so that expiry reminders reach someone.
- Check again after you install a new certificate, to see the new dates.
Good to Know
- Public websites only. The check is done by an outside service, so it cannot reach localhost, private networks or sites behind a firewall.
- The exact name matters. Type the full name you want to check, including a subdomain if there is one.
- Standard HTTPS only. The tool looks at the usual HTTPS connection of the site.
- It may differ from your browser. Sites behind a CDN or load balancer can show different certificates in different places.
- Basic details only. The tool does not test your server settings, your code or whether your site is safe.
- It depends on an outside service. If that service is slow or busy, the check can be slow or can fail. Try again after a moment.
Common Mistakes
- Reading Secure as safe: A valid certificate does not prove that a site is honest.
- Checking the wrong name: A certificate for the main domain may not cover a subdomain.
- Trying to check a private address: Internal sites cannot be reached by the outside service.
- Waiting until the last day to renew: Leave time to fix problems.
- Forgetting to install the renewed certificate: Renewing is not enough, the server must use the new file.
- Forgetting the time zone: Expiry times are in UTC and can fall on another day for you.
- Typing secrets into the box: Only type a public website name.
Privacy
- A web browser cannot read the certificate of another website directly. This tool therefore asks a third-party certificate checking service to fetch it, and the domain name you type is sent to that service.
- Public scanning services may keep logs of requests and may handle the data under their own terms.
- Enter only public website names. Do not enter private or internal addresses, passwords, keys or other secrets.
- The result is a basic certificate check and not a security audit.
Frequently Asked Questions
How do I check the SSL certificate of a website?
Type the domain, for example google.com, or the full address, for example https://example.com, then click Check SSL. The tool shows the issuer, the valid from and valid until dates and the days remaining, together with a green Secure badge or a red warning.
What is an SSL certificate?
An SSL certificate is a digital file that a website uses to prove its identity and to encrypt the connection between the website and the visitor. It is what makes the address start with https and shows the lock icon in the browser. Modern websites actually use TLS, the newer version of the protocol, but the name SSL is still widely used.
What is the difference between SSL and TLS?
TLS is the newer and more secure successor of SSL. The old SSL versions are no longer considered safe and are switched off on modern servers. People still say SSL certificate for convenience, and the certificate itself works for TLS.
What does the issuer mean?
The issuer is the certificate authority (CA), the organization that checked the request and signed the certificate, for example Let's Encrypt or Google Trust Services. Browsers and devices trust a certificate only if it comes from a certificate authority that they know and trust.
What do Valid From, Valid Until and Days Remaining mean?
Valid From is the date and time when the certificate started to be valid. Valid Until is when it stops being valid. Days Remaining is the number of days between today and the Valid Until date. After the Valid Until date, browsers show a security warning to visitors.
What happens when an SSL certificate expires?
Browsers show a full-page warning that the connection is not private, and many visitors leave. Some apps, APIs and payment or login flows stop working completely. The fix is to renew or replace the certificate and install it on the server.
What does the green Secure badge mean?
It means that the certificate the checker received is currently within its validity dates and was reported as valid. It does not mean that the website itself is trustworthy, safe or free from scams, because criminals can also get valid certificates for their sites.
Why do I see a red warning?
The certificate is expired, not yet valid, or reported as invalid, for example because the name does not match the website, it is self-signed, it comes from an authority that is not trusted or the server did not send a complete certificate chain. The warning shows that something needs attention. It does not always show every reason, so check your server and certificate setup.
Is my domain sent to another service?
Yes. A web browser cannot read the certificate of another website directly, so this tool asks a third-party certificate checking service to fetch it. The domain name that you type is therefore sent to that service. Do not enter private or internal addresses, and do not type passwords or secrets. Public scanning services may also keep logs of requests.
Can I check localhost, an intranet site or a private server?
No. The check is done by an outside service that can only reach websites that are open on the public internet. A site on localhost, a private network or behind a firewall cannot be checked this way.
Why does the check sometimes take a while or fail?
The certificate is fetched by an outside service, so the speed depends on that service. It can be slow, busy or limit the number of requests, and it may fail if the website is down, does not support HTTPS, or blocks the checker. Wait a moment and use Check Again.
Why does the result differ from what my browser shows?
Websites behind a CDN or load balancer can show different certificates to different visitors or locations, and the certificate may have been renewed very recently. The checker also looks at the standard HTTPS port. If you see a difference, check again later and look at your server setup.
Does the checker cover subdomains and wildcard certificates?
It checks the exact name that you type. A certificate for example.com does not automatically cover shop.example.com unless it was issued for it, for example as a wildcard certificate. To check a subdomain, type the full subdomain.
How early should I renew a certificate?
A common habit is to renew at least a few weeks before the expiry date, so that there is time to fix problems. Many hosting providers and certificate authorities can renew automatically, and it is still worth checking now and then that the automatic renewal really works.
Is this SSL checker free, and is it a security audit?
The tool is free and needs no signup. It shows basic certificate details only and is not a security audit. It does not test your server settings, your website code or whether your site is safe.