About the tool
Private key checks, in your browser.
This workbench runs entirely locally. No private keys or other data are sent to a server.
How it works
Check My Private Key uses the browser's Web Crypto API and WebAssembly for cryptographic operations. WebAssembly provides high-performance parsing for formats that browser APIs do not cover directly, including RSA, EC, PKCS#8, and JWK.
Your key stays in the current page while it is being checked or generated. It is not saved automatically.
Supported key types
| Key type | Algorithm | Sizes / curves | Password protection |
|---|---|---|---|
| RSA | RSASSA-PKCS1-v1_5 | 2048, 3072, 4096 bits | Yes |
| ECDSA | ECDSA | P-256, P-384, P-521 | Yes |
| Ed25519 | Ed25519 | N/A | No |
Frequently asked questions
- What key formats are supported?
- The check page accepts PEM-encoded RSA, EC, and Ed25519 private keys, including RSA PKCS#1 and encrypted PKCS#8 keys.
- Why can't I password-protect Ed25519 keys?
- Browser cryptography APIs do not support password encryption for Ed25519 keys.
- What browsers are supported?
- Modern Chrome, Firefox, Safari, and Edge browsers with WebAssembly support.