SSL Labs
ssllabs.com/ssltest
Free SSL/TLS configuration testing tool that grades your server security and identifies vulnerabilities.
Why it is useful
The industry standard for auditing HTTPS configuration. Gives a letter grade plus detailed breakdown of cipher suites, certificate chains, protocol support, and known vulnerabilities like POODLE and Heartbleed.
More in Developer Utilities
Other developer utilities you might not have heard of.
- DBeaverUniversal database GUI supporting PostgreSQL, MySQL, SQLite, MongoDB, Redis, and 80+ others with a SQL editor, ER diagrams, and data export.
- readme.soA drag-and-drop editor for building a GitHub README, with ready-made sections you can reorder, edit and export as Markdown.
- VaultwardenLightweight, unofficial self-hosted server compatible with Bitwarden clients — run your own password manager backend instead of paying for 1Password.
- Code BeautifyFormat, validate, and beautify JSON, XML, CSS, SQL, and dozens of other code and data formats instantly in your browser.
- OpenRouterA unified API gateway that routes requests to dozens of large language models through a single endpoint and API key.
- MXToolboxA suite of free network diagnostic tools focused on email infrastructure — MX record lookup, SPF/DKIM/DMARC testing, blacklist checking, and SMTP diagnostics.