Public & Private Key Analyzer
Identify key algorithms and formats, inspect key sizes and curves, and calculate fingerprints locally in your browser.
Key input
Paste a PEM or OpenSSH key, or upload a PEM, KEY, PUB, or DER file.
Cryptographic keys
Inspect public and private key material safely
Key analysis helps identify the algorithm, encoding, key size, curve, and fingerprints before a key is used in TLS, SSH, JWT, signing, or encryption workflows.
What this tool identifies
Detect RSA, elliptic-curve, Ed25519, and OpenSSH key formats, inspect key sizes or curves, distinguish public and private material, and calculate key fingerprints locally.
Protect private keys
Private keys must remain confidential. Use this tool only in a trusted browser environment, avoid sharing private material, and never paste production keys into logs, tickets, or public chats.
Guide
About Public and Private Key Analyzer
Cryptographic keys appear in several containers and encodings, including PEM, DER, PKCS#8, SubjectPublicKeyInfo, and OpenSSH formats.
This analyzer identifies key type and format, reports sizes or curves, and calculates fingerprints.
Private keys are sensitive and should be analyzed only in a trusted environment.
Key types and formats
The analyzer recognizes common public and private key representations.
- RSA keys
- Elliptic-curve keys
- Ed25519 keys
- PEM containers
- OpenSSH public keys
Key strength details
RSA security depends partly on modulus size, while EC and Ed25519 keys use specific curves or algorithms.
Fingerprints
Fingerprints help identify and compare public keys without displaying the full key.
Private-key safety
Never publish private keys or paste production keys into tickets, logs, public repositories, or untrusted tools.
FAQ
Frequently asked questions
How can I tell whether a PEM contains a public or private key?
The PEM label and decoded structure identify the key type.
What is PKCS#8?
PKCS#8 is a common container format for private keys.
What is SubjectPublicKeyInfo?
It is a standard ASN.1 structure used to encode public keys and their algorithm identifiers.
Can I derive a public key from a private key?
Yes, for supported asymmetric algorithms.
What is a key fingerprint?
It is a hash-based identifier derived from encoded public key material.
Are keys uploaded?
Analysis is intended to occur locally in your browser.
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