Free, vendor-neutral browser tools for PKI practitioners
Everyday certificate work — checking a key pair, decoding a CSR, generating a new request, or converting a file format — without an account, a backend, or a reason to trust anyone else with your certificates and keys.
Every tool below runs entirely in your browser — nothing you paste or upload is ever sent anywhereChoose a tool
Each tool is a single, self-contained page focused on one task.
Certificate & CSR Validator
Check whether a TLS certificate and a CSR share the same key pair, and see both side by side.
Open tool → DecoderCSR Decoder
Paste or upload a CSR to see its subject, public key, signature algorithm, and requested SANs.
Open tool → DecoderCertificate Decoder
Decode an issued certificate: subject, issuer, expiry countdown, SANs, and key usage at a glance.
Open tool → ChainCertificate Chain Validator
Paste a leaf certificate plus its intermediates and root, and verify every signature resolves up to a trusted root.
Open tool → GeneratorCSR Generator
Fill in your certificate details and get an OpenSSL command to run on your own server — no key ever touches this page.
Open tool → ConverterCertificate Format Converter
Convert a certificate between PEM and DER, with a summary of what you're converting first.
Open tool → ReferencePKI & Private Key Security FAQ
Plain-English answers about CSRs, certificate chains, and how to keep private keys safe.
Open tool →Certificate work shouldn't require trusting a stranger's server
Certificates and CSRs contain identifying details, and generating either one starts with a private key that should never leave the machine that created it. These tools exist so you can do routine PKI checks without uploading anything to a backend you can't see.
Static pages, no server, no accounts
Every page on this site is a single, self-contained HTML file that runs entirely client-side. There's nothing to sign up for and nothing to configure — paste your data, get your answer, and close the tab.
Developers, administrators, and curious non-experts alike
Whether you manage certificates daily or are troubleshooting one for the first time, each tool page explains what it's showing you in plain language, not just cryptographic jargon.
Abhimukta Banerjee
Abhimukta Banerjee is a lifelong technologist, cybersecurity practitioner, and PKI enthusiast with over 25 years of experience building and operating secure enterprise platforms. As a VP of IAM and PKI Platform Operations at a Fortune 500 financial institution, he works at the intersection of identity, certificates, access control, compliance, and cloud security. He launched PKI Toolkit to share the kinds of practical tools he wished he had throughout his career — simple, private, browser-based utilities that make certificate and TLS-related tasks easier for engineers, administrators, and security teams.
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