The self-hosted toolbox for sysadmins and security work.
Subnets, certificates, DNS, mail records, Windows error codes and the rest of the daily lookups — in one container you run yourself. Nothing is logged, nothing is sent to a third party, and the tools that touch secrets never leave your browser.
Certificate / CSR decoder
Decode certificates and CSRs without contacting a server
in browser
Hash generator
Compute MD5, SHA-1, SHA-256, SHA-384 and SHA-512 digests and verify a checksum
in browser
HTTP security headers
Grade a site's response headers and see exactly which protections are missing
server
JWT decoder
Decode a JSON Web Token's header and claims without sending it anywhere
in browser
Password generator
Generate passwords or passphrases in your browser and see their real entropy
in browser
security.txt validator
Check a domain's security.txt for RFC 9116 fields, expiry and HTTPS delivery
server
TLS certificate checker
Check a certificate's expiry, names, issuer, key strength and negotiated protocol
server