The Best SSL for Free Alternatives in 2026

ZeroSSL issues online SSL certificates and supports HTTPS setup through a certificate management interface.

Test HTTP security headers such as CSP and HSTS, then review recommendations for improving a site.

Obtain a certificate for a website with Certbot, which helps configure HTTPS.

Protect a website from automated bot requests with Anubis, which evaluates incoming HTTP requests.

Manage two-factor authentication codes with OTP Auth, an iOS app listed on the App Store.

Configure DNS over HTTPS in curl, the command-line transfer tool and library.

Configure DNS over HTTPS on iOS and macOS using the provided configuration profiles.

Generate secure SSL configurations for selected web, database, and mail software.

Anubis weighs incoming HTTP requests to help block AI crawlers before they access a website.

Add proof-of-work verification to websites with mCaptcha, a privacy-focused automated CAPTCHA system.

Solve reverse engineering challenges published on challenges.re, a challenge-focused site.

GoPlus offers Web3 security tools including audits, APIs, a user security hub, and a browser extension.

Search the National Vulnerability Database, a public resource for vulnerability information.

WhatsMyDNS checks DNS record propagation across global resolvers for record types including A, AAAA, MX, and TXT.

Find which websites support two-factor authentication and what methods they offer in this directory.

View Toronto Police calls for service on a map that updates in real time, according to the supplied page description.

Use Metasploit to find security issues, verify mitigations, and manage authorized penetration testing assessments.

The Snyk Security Database provides vulnerability details and remediation guidance for packages and cloud configurations.

The URL Decoder and Encoder converts text between encoded and decoded forms, including JavaScript URLs.

Lucia was deprecated in March 2025. The website was updated in July 2026 and points to code/auth_session.ts as a single-file replacement for the NPM package and to the Auth Book for auth information.

DNSPerf compares the performance and uptime of enterprise and commercial DNS providers.

Search a community-curated collection of bug bounty writeups and learning resources.

UUID Tools generates individual or bulk UUIDs and supports multiple UUID versions.

Browse sample photos and camera settings for different photography cameras and lenses.