SSL Certificate Checker — Free HTTPS & TLS Validator
Check any domain's SSL certificate instantly. See issuer, expiry date, days remaining, TLS version, and SANs. Works on any website. Free, no login required.
What is a SSL Certificate Checker?
An SSL Certificate Checker is a free browser-based tool that connects to any domain over HTTPS, retrieves its TLS certificate, and displays the key details: issuer, subject, valid from and until dates, days remaining before expiry, TLS version, and the Subject Alternative Names (SANs) the certificate covers. You enter a domain name and get results in seconds — no login, no installation. It reads the same certificate your browser reads when it shows the padlock, so results are always accurate to the live certificate currently served by that domain.
When Should You Use SSL Certificate Checker?
Check your SSL certificate before a domain migration, after switching hosting providers, or any time a browser throws a certificate warning. Run it on every domain you manage at least 30 days before the renewal date — most Let's Encrypt certificates auto-renew, but automation failures are common and a missed renewal takes a site offline within hours. It is also useful when auditing a client site for the first time: an expired or misconfigured certificate is an immediate red flag that the technical baseline needs attention before any SEO work starts.
How to Read SSL Certificate Checker Results
The issuer field names the Certificate Authority that signed the certificate — Let's Encrypt for free auto-renewing certs, DigiCert or Sectigo for commercial ones. The valid from and valid until dates define the certificate's active window. Days remaining counts down to expiry — anything under 30 is amber, under 0 is expired. The TLS version confirms whether the server uses TLS 1.2 or TLS 1.3; TLS 1.3 is faster and more secure. Subject Alternative Names list every domain and subdomain the certificate covers — confirm your domain appears here or the browser will show a mismatch error.
What Should You Know Before Using SSL Certificate Checker?
This tool checks the live certificate served at port 443 — it does not check certificates on non-standard ports or internal servers not publicly accessible. A result of 'no certificate found' means the domain either does not have HTTPS configured or is blocking external connections on port 443. HTTPS is a confirmed Google ranking factor, and a site serving HTTP only — or an expired certificate — is flagged as 'Not Secure' in Chrome, which increases bounce rate. Check every domain you own, including subdomains, as certificates do not automatically cover subdomains unless listed as SANs.
Frequently Asked Questions
Does SSL affect SEO rankings?
Yes. Google confirmed HTTPS as a ranking signal in 2014. Sites still serving HTTP receive a 'Not Secure' warning in Chrome, which increases bounce rate and suppresses organic clicks. An expired certificate has the same effect — browsers block access with a full-screen warning, eliminating traffic entirely for as long as the certificate remains expired. Fixing SSL is one of the fastest-impact technical SEO tasks available.
How do I know when my SSL certificate expires?
Run the SSL Certificate Checker on your domain and look at the Days Left field. Any result under 30 days needs immediate attention. Most hosting providers send expiry email reminders, but these often go to the server administrator's address rather than yours. Set a calendar reminder 45 days before the expiry date shown in results to guarantee renewal before Chrome starts blocking visitors.
What is the difference between TLS and SSL?
SSL (Secure Sockets Layer) is the original encryption protocol, deprecated since 2015. TLS (Transport Layer Security) is its successor and what all HTTPS connections actually use today. TLS 1.2 and TLS 1.3 are the current versions — 1.3 is faster and more secure. The term 'SSL certificate' is shorthand that stuck despite the protocol being TLS. Your certificate is technically a TLS certificate regardless of what your host calls it.
What causes an SSL certificate to be invalid?
The most common causes are: the certificate has expired, the domain is not listed in the certificate's Subject Alternative Names (a mismatch error), the certificate was issued by an untrusted CA not in the browser's root store, or the domain is still serving HTTP with no HTTPS redirect. The SSL Certificate Checker identifies which of these applies and shows the specific fields that confirm the problem.
How do I check SSL certificate for free?
Enter any domain name into Scrawl's SSL Certificate Checker at scrawl.tools/tools/ssl-checker. No account, no browser extension, and no paid plan needed. The tool connects directly to the domain, reads the live TLS certificate, and shows the issuer, expiry date, days remaining, TLS version, and every domain the certificate covers. Results appear in under 3 seconds for most domains.
Related Tools
Security Headers Checker
Audit HTTP security headers, get a letter grade, and copy ready-made Apache, Nginx and Cloudflare fixes.
Schema Checker
Validate structured data markup against schema.org guidelines to secure rich snippets in SERPs.
Structured Data Generator
Generate valid JSON-LD schema markup for Article, Product, LocalBusiness, FAQ, Breadcrumb and more.