DNS Studio tool

Check TLS configuration clearly.

Decode certificates, generate CSRs, test HTTPS security, and learn how TLS really works — all in your browser.

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Free, focused checks — nothing about your domain is stored.Verbose outputi

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Enter a domain to test its TLS configuration.

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Modern TLS & HTTPS Tools for Certificate Management

Our comprehensive suite of TLS tools helps engineers, DevOps professionals, and security practitioners manage certificates efficiently. Every tool runs in your browser, ensuring your private keys and sensitive certificate data never leave your device. Whether you need to decode an X.509 certificate, generate a Certificate Signing Request, test security headers, or understand TLS handshakes, we provide the tools you need.

Why Choose Our TLS Tools?

Our platform offers a comprehensive collection of TLS and HTTPS tools designed for professionals who work with certificates regularly. We understand the importance of security, privacy, and efficiency when managing SSL/TLS certificates. Managing digital certificates is a critical task for any organization that values security and compliance.

Privacy-first approach: No logins required, no tracking of certificate contents. All certificate processing happens in your browser, ensuring maximum privacy and security for your sensitive data. Your private keys and certificate information remain completely confidential.
Browser-first architecture: Most tools work entirely client-side using modern web technologies. Your private keys and certificate data never leave your device, providing enterprise-grade security without the need for server-side processing.
Focused on TLS expertise: Built specifically for engineers, DevOps professionals, and security practitioners who work with certificates daily. Every tool is designed with real-world workflows in mind, from certificate decoding to CSR generation.
Educational resources: Beyond tools, we provide comprehensive TLS Academy content covering fundamentals, best practices, cipher suites, and certificate lifecycle management. Learn how TLS works while using our practical tools.

Whether you're decoding a certificate to check its validity, generating a CSR for a new domain, testing security headers, or learning about TLS handshakes, our platform provides everything you need in one convenient, privacy-focused location. Our tools support both RSA and ECDSA key types, handle multiple certificate formats, and provide detailed insights into certificate chains and security configurations.

Certificate management doesn't have to be complicated. With our intuitive interface and powerful tools, you can quickly verify certificate validity, check expiration dates, analyse certificate chains, and ensure your TLS configuration meets security best practices. All without compromising your privacy or security.

Common Use Cases

Certificate Validation

Quickly verify certificate validity, check expiration dates, and identify potential security issues. Our certificate decoder provides detailed information about subject, issuer, validity periods, and extensions in an easy-to-read format.

Perfect for troubleshooting certificate problems, auditing your certificate inventory, or verifying certificates before deployment. The decoder supports both PEM and DER formats, making it compatible with certificates from any source.

CSR Generation

Generate Certificate Signing Requests directly in your browser without exposing private keys. Our CSR generator supports RSA and ECDSA key types, includes Subject Alternative Names, and ensures your private keys never leave your device.

Ideal for creating new certificates, renewing existing ones, or generating CSRs for multiple domains. The tool handles all the complex ASN.1 encoding automatically, so you can focus on providing the certificate details.

Security Testing

Test your website's HTTPS configuration, check security headers, verify redirects, and detect mixed content issues. Our HTTP tester and security header generator help ensure your site meets modern security standards.

Essential for security audits, compliance checks, and ensuring your TLS configuration follows industry best practices. Identify missing security headers, verify HSTS implementation, and catch configuration issues before they become problems.

Certificate Chain Analysis

Visualise and analyse certificate chains from leaf to root. Understand the trust relationships, identify intermediate certificates, and verify chain completeness. Our chain visualiser makes it easy to see the entire certificate hierarchy.

Critical for troubleshooting certificate validation issues, understanding trust paths, and ensuring proper certificate installation. The visual representation helps identify missing intermediate certificates or chain configuration problems.

Getting Started

Getting started with our TLS tools is simple and requires no registration or setup. All tools are immediately available in your browser, ready to use whenever you need them. Here's how to make the most of our platform:

Decode a certificate: Paste any PEM or DER certificate into our certificate decoder to see detailed information about its subject, issuer, validity, and extensions. Perfect for quick certificate checks or troubleshooting.
Generate a CSR: Use our CSR generator to create Certificate Signing Requests for new certificates. Fill in the required fields, select your key type, and download the CSR and private key securely.
Test your domain: Enter any domain in our domain tester to run comprehensive security checks including HTTPS availability, redirect configuration, and security header analysis.
Learn TLS: Explore our TLS Academy for in-depth articles on TLS fundamentals, cipher suites, certificate lifecycle, and best practices for secure certificate management.

Our tools are designed to be intuitive and powerful, whether you're a seasoned security professional or just getting started with certificate management. Every tool includes clear instructions and helpful error messages to guide you through the process.

Related tools

TLS Studio focuses on protocol-level checks: chains, handshakes, headers, and the certificate plumbing behind HTTPS. If you just want a quick, beginner-friendly read on whether a certificate is valid and when it expires, try SSL Studio — another DNS Studio tool. For the records behind your domain, start with DNS Studio.