免費的 SSL/TLS 憑證檢查器和驗證器。檢查憑證有效性、到期日期、鏈條正確性，並獲取任何網域的續約建議。
🔒 We do not store any generated certificates, private keys, or uploaded files. All processing happens in memory and is immediately discarded. Learn more in our Privacy Policy
Enter a domain name to check its SSL/TLS certificate validity, expiry date, chain correctness, and get renewal recommendations.
Use this tool to verify SSL/TLS certificate status for any domain, check expiration dates, validate certificate chains, and receive recommendations for certificate renewal.
Our free SSL/TLS certificate checker is a powerful online tool that allows you to verify the certificate status of any domain in real-time. Simply enter a domain name, and our tool will connect to the server over HTTPS (port 443), retrieve the SSL certificate, validate the certificate chain, check expiration dates, verify certificate validity, and provide comprehensive certificate information and renewal recommendations. This is one of the most essential SSL tools for website administrators, DevOps engineers, and security professionals.
Whether you need to check SSL certificate expiry, verify certificate chain validity, monitor certificate expiration dates, or troubleshoot SSL/TLS connection issues, our certificate checker provides instant results with detailed certificate information including issuer details, subject information, SANs (Subject Alternative Names), certificate fingerprints, and more.
Our SSL certificate checker provides comprehensive certificate information and validation:
Certificate checking is essential for website security, compliance, and maintenance:
Our SSL certificate checker uses secure TLS connections to retrieve and validate certificates:
Our certificate checker helps identify and resolve common SSL certificate problems:
Simply enter your domain name in our SSL certificate checker. The tool will connect to your domain over HTTPS, retrieve the certificate, validate the certificate chain, check expiration dates, and display comprehensive certificate information including validity status, expiry date, days remaining, and any certificate issues.
A certificate is marked as "expiring soon" if it will expire within 30 days. We recommend renewing SSL certificates at least 30 days before expiration to avoid service interruptions, browser warnings, and security issues. Our tool provides recommended renewal dates to help you plan certificate renewals in advance.
If the certificate chain is invalid, our tool will identify the specific issues, such as missing intermediate certificates, untrusted root CAs, self-signed certificates, or incomplete chains. This helps you diagnose and fix certificate configuration problems. You may need to install intermediate certificates or update your certificate chain configuration.
Yes, you can check SSL certificates for any domain by entering the domain name. Our tool supports checking certificates for any publicly accessible domain over HTTPS. Simply enter each domain name separately to check multiple domains and monitor their certificate status.
Our SSL certificate checker connects to domains over HTTPS on the standard port 443, which is the default port for secure HTTPS connections. This covers the vast majority of websites and SSL/TLS implementations. The tool automatically uses port 443 for all certificate checks.
We recommend checking SSL certificates regularly, especially when certificates are approaching expiration. For certificates expiring within 30 days, check more frequently. Many organizations check certificates monthly or set up automated monitoring to receive alerts before expiration. Our tool provides renewal recommendations to help you plan ahead.
Our certificate checker provides comprehensive SSL certificate information including validity status, expiration date, days remaining, certificate chain validation, issuer details, subject information, SANs (Subject Alternative Names), public key information, signature algorithm, certificate fingerprints, and renewal recommendations. All information is displayed in an easy-to-read format.
Follow these best practices for SSL certificate management:
OneClickTLS is an online tool that helps developers instantly generate self-signed TLS and mTLS certificates. Instead of searching for complicated OpenSSL commands or creating long scripts, you can generate certificates in seconds by entering your Common Name and SANs. Whether you're looking for TLS generation online or need to generate TLS certificates quickly, this tool provides a fast and secure solution. The tool uses a powerful Go backend with advanced certificate generation capabilities. All processing happens securely on the server, and produces ready-to-use certificate and key files for development and testing environments.
Self-signed certificates are commonly used for development, debugging, local HTTPS setups, staging environments, internal services, and API testing. They help simulate secure communication without requiring a trusted certificate authority. A properly created certificate prevents browser warnings and avoids repetitive manual OpenSSL commands.
Traditionally, developers need to run commands like:
openssl req -new -newkey rsa:2048 -nodes -keyout key.pem -out cert.pem \
-subj "/CN=example.com" \
-addext "subjectAltName=DNS:example.com,DNS:www.example.com"These commands are powerful, but they are also difficult to remember. OneClickTLS eliminates this problem by creating TLS certificates automatically based on simple form inputs.
When it comes to mTLS (mutual TLS), the complexity increases significantly. Setting up mTLS requires generating a Certificate Authority (CA), server certificates, client certificates, and managing certificate chains - a process that can involve multiple OpenSSL commands and configuration files. OneClickTLS simplifies this entire workflow, generating a complete mTLS certificate suite with just a few clicks, saving developers significant time and reducing the chance of configuration errors.
Developers choose this tool when they need to test secure connections quickly, including:
Self-signed certificates are not trusted by browsers or clients in production environments. They are only intended for testing, development, or internal systems where trust can be manually configured.
Subject Alternative Names allow a certificate to support multiple domains or IPs. Modern browsers and TLS clients often ignore the Common Name and rely on SAN values for verification.
Yes, OneClickTLS is safe to use. As detailed in our Privacy Policy, we do not store any generated certificates, private keys, or uploaded files. All processing happens in server memory and is immediately discarded after the response is sent. Your data is never logged, tracked, or shared with third parties. All communication is encrypted via HTTPS to protect your data in transit.
TLS (Transport Layer Security) is the modern successor to SSL (Secure Sockets Layer). While the terms are often used interchangeably, TLS is the current standard for secure communications. Our tool generates TLS certificates that are compatible with all modern systems.
Yes! OneClickTLS certificates work perfectly with Kubernetes Ingress controllers, service meshes, and other Kubernetes components that require TLS certificates. Simply generate your certificate and configure it in your Kubernetes secrets.
After generating your certificate, you can install it in your web server (Nginx, Apache, etc.) or application. For local development, you may also need to add the certificate to your system's trust store to avoid browser warnings.
OneClickTLS helps with the following search terms and use cases:
OneClickTLS makes it simple to generate self-signed TLS or mTLS certificates without dealing with long command line instructions. It is fast, private, browser based, and built for developers who need self-signed certificates for development and testing environments. Self-signed certificates are perfect for local development, internal services, and testing scenarios where a trusted certificate authority is not required. This page helps search engines understand the purpose and value of the tool, allowing it to rank naturally without frequent updates.