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RSA Key Pair Generator — Free, Runs in Your Browser
Generate an RSA public/private key pair entirely client-side using the Web Crypto API — the private key is computed in your browser and never sent to a server, which matters because a private key generated on someone else's server is a private key that server has seen. Choose your key size and export in PEM format.
How to use RSA Key Gen
- Choose your key size (2048-bit is the common minimum today).
- Generate the key pair.
- Copy or download the public and private keys in PEM format.
- Keep the private key secret — never share or upload it elsewhere.
Frequently asked questions
- What key size should I use?
- 2048-bit is the current practical minimum; 4096-bit is more conservative and still fast enough for most uses. Below 2048-bit is considered too weak for new keys.
- Is it actually safe to generate a private key in a browser?
- The generation uses the Web Crypto API's cryptographically secure random number generator and never transmits the key — the same underlying primitive real crypto libraries use, run locally instead of on a server you have to trust.
- Can I use this key for SSH?
- The generated PEM key can be converted to SSH format with a standard tool like ssh-keygen -i; this tool outputs standard RSA PEM, not the SSH wire format directly.
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