Generate self-signed cert for localhost dev, all in-browser. Free self signed certificate generator.
The Self-Signed Certificate Generator creates a certificate signed by its own key (self-signed) for use in development and testing. No CA is involved; you get a certificate and private key that you can install on a local server (e.g. localhost, 127.0.0.1, or a dev hostname). The tool runs in the browser so the private key never leaves your machine. Use it for HTTPS on a local app server, for testing TLS-dependent code, or for internal tools where you add the cert to your trust store. Browsers will show a warning for self-signed certs unless you add an exception or install the cert as trusted. Never use self-signed certs for production; use a proper CA or internal PKI for that.
For local dev you often don't need a public CA. Self-signed is quick and free; you control the key and validity.
Add the certificate to your OS or browser trust store, or use a local CA (e.g. mkcert) that you trust once.
For dev, 365 days or more is common. You can regenerate when it expires.
Yes. Add SANs for localhost, 127.0.0.1, and any dev hostnames you use.
No. Use a trusted CA or your organization's PKI for production. Self-signed is for dev/test only.