JWK and PEM Public Key Converter
Convert RSA or P-256 public keys between JWK JSON and SPKI PEM locally.
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How to use JWK and PEM Public Key Converter
Convert RSA or P-256 public keys between JWK JSON and SPKI PEM locally. The browser imports and exports public key material only. Private/symmetric JWK members and private PEM blocks are rejected before conversion.
- Provide the input and select the documented mode or options.
- Run the tool and review its result and any limits reported below.
- Copy the text result or download a separate output file.
Good to know
- RSA uses RS256 with a canonical odd2048–8192-bit modulus and odd exponent3–2^32−1; EC uses P-256. PEM must contain exactly one PUBLIC KEY block.
- Conversion does not establish trust, certificate identity, ownership or authorization.20,000 input characters.
- Processing happens in this browser tab. Inputs and results are not automatically saved or uploaded.
Common questions
What does JWK and PEM Public Key Converter process?
The browser imports and exports public key material only. Private/symmetric JWK members and private PEM blocks are rejected before conversion.
What happens to my original input?
The tool creates a separate result. Selected files and pasted data remain on this device; inspect the result before using it in another system.
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