Looking for something like Let's Encrypt? Here are 24 alternatives, ranked by how closely they match it on purpose, features and platforms. Of these, 3 are free or have a free plan and 5 are open source.
Let’s Encrypt is a nonprofit that provides automated TLS certificates for securing websites with HTTPS.
| # | Alternative | Pricing | Open source | Platforms |
|---|---|---|---|---|
| 1 | Online Tools | — | Not stated | Web |
| 2 | RSA encryption, decryption and prime calculator | — | Not stated | Web |
| 3 | Evervault | — | Not stated | Web |
| 4 | Wazuh | Free trial | Not stated | Web |
| 5 | Awesome Cryptography | — | Not stated | — |
| 6 | SSL for Free | Free | Not stated | Web |
| 7 | Anubis | — | Not stated | Web |
| 8 | ZeroSSL | — | Not stated | Web |
| 9 | mCaptcha | — | Not stated | Web |
| 10 | mitmproxy | — | Yes | Linux, Web, Windows |
Online Tools offers browser-based utilities for hashing, encoding, encryption, formatting, compression, file processing, and more.
This RSA calculator supports prime generation, encryption, and decryption.
Protect payment data with Evervault’s encryption model while retaining control of the payment experience.
Wazuh monitors systems and detects threats through an open source security platform for organizations.
This GitHub list curates cryptography resources and links for people exploring the field.
SSL for Free provides SSL and wildcard certificates for enabling HTTPS on websites.
Protect a website from automated bot requests with Anubis, which evaluates incoming HTTP requests.
ZeroSSL issues online SSL certificates and supports HTTPS setup through a certificate management interface.
Add proof-of-work verification to websites with mCaptcha, a privacy-focused automated CAPTCHA system.
Inspect HTTPS traffic interactively with mitmproxy, an open-source proxy tool.
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.
Intercept, inspect, and edit HTTP(S) traffic with HTTP Toolkit for debugging and testing.
Create locally trusted development certificates for arbitrary names with mkcert.
Manage two-factor authentication codes with OTP Auth, an iOS app listed on the App Store.
Configure DNS over HTTPS on iOS and macOS using the provided configuration profiles.
Configure DNS over HTTPS in curl, the command-line transfer tool and library.
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.
Cap provides a self-hosted, open source alternative to CAPTCHA challenges for websites.
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.
Alternatives are suggested from the purpose and features described in our listings. Different pages for the same product appear once. Read each description to check whether it fits your task. How we choose alternatives · Suggest an alternative
