OpenSSL Command Generator
Build the exact OpenSSL command for keys, CSRs and certificate checks.
What do you need?
Pick a task and fill in the details
Command
Great for local HTTPS and staging.
openssl req -x509 -newkey rsa:2048 -nodes \
-keyout key.pem -out cert.pem \
-days 825 -subj "/C=US/O=Example Inc/CN=example.com" \
-addext "subjectAltName=DNS:example.com,DNS:www.example.com,IP:127.0.0.1"The command is built entirely in your browser — no keys, certificates or domains are sent anywhere. Run it locally where OpenSSL 1.1.1 or 3.x is installed.
About the OpenSSL Command Generator
Pick a task — generate an RSA or EC key, create a CSR, make a self-signed certificate, inspect a certificate, convert PEM to PFX or test a TLS endpoint — fill in the subject and options, and copy a correct OpenSSL command. No more hunting through man pages for the right flag order.
Examples
Self-signed cert
example.com, 365 daysOutput
openssl req -x509 -newkey rsa:2048 ...Keyboard shortcuts
- Copy the main outputCtrl / ⌘ + Shift + C
- Download the resultCtrl / ⌘ + S
- Share this toolCtrl / ⌘ + Shift + S
- Reset the inputsAlt + R
- Open the tool search paletteCtrl / ⌘ + K
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Frequently asked questions
Read more
- OpenSSL commands and key formats, explained without the man page
CSRs, self-signed certificates, PEM vs DER vs PKCS#8 vs JWK, and how to check what a certificate actually contains.
Version 1.0.0 · Updated 2026-08-22 · Runs entirely in your browser