Security & Crypto Tools
Digital Signature Verifier
Verify RSA-PSS or ECDSA signatures over a message.
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What is Sig Verifier?
A signature verifier for confirming a message was signed by the holder of a public key, supporting RSA-PSS and ECDSA.
How it works
The public key and signature are imported and checked with crypto.subtle.verify; the result is a pass/fail indicator.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Verifying a signed message
Paste a message, its signature, and a public key to verify authenticity — RSA or ECDSA.
Common mistakes
Algorithm/key mismatches
The key type must match the signature algorithm — an ECDSA signature can't be verified with an RSA public key.
Frequently asked questions
What does verification prove?
That the message was signed by the holder of the matching private key and hasn't been altered since.
What key formats are accepted?
PEM-encoded public keys for RSA and ECDSA, with the signature in base64 or hex.