Verifiers, Converters & Diagnostic Tools

What this cluster is for

Verifiable credentials are signed claims — diplomas, badges, identity attestations, permissions — that holders keep themselves and present to verifiers on demand. When one misbehaves, the failure is almost always in one of four places: its structure (does the JSON carry the required fields in the required shapes), its signature (was it really issued by whoever it claims), its status (has it been revoked since issuance), or its keys (getting the issuer's public key into the format your tool wants). This cluster is one tool per failure mode:

• JSON-LD & Open Badges 3.0 schema verifier — a twelve-point structural audit of a W3C VC 2.0 or Open Badges 3.0 payload: @context, types, issuer, subject, timestamps, proof block. Structure only, but field by field.
• SD-JWT & Key Binding verifier — real RFC 9901 verification: the Ed25519 issuer signature recomputed with WebCrypto, every salted SHA-256 disclosure digest matched against the payload, and the holder's key-binding proof checked. The demo buttons construct a genuinely signed token in your tab.
• Bitstring status list decoder — unpacks the gzipped, base64-encoded revocation lists behind credential status checking and reads the bit for any index.
• JWK ↔ PEM ↔ Base64 key converter — moves public keys between JSON Web Key, SPKI PEM, hex, and base64url for Ed25519, RSA, and ECDSA P-256.

All four run entirely in your browser. That is the design point, not a marketing line: credentials are personal data and keys are their trust anchors, and the sane default is to never paste either into a server-side validator you cannot audit. Nothing you paste into these pages is uploaded, stored, or logged; the only network call any of them can make is fetching this site's own DID document, for tokens this site issued.

One honest note: these pages carry noindex on purpose — they are utility surfaces, not content pages — so a bookmark is the reliable way back.