Cert Tool

by mkontani · Developer Tools

Manifest V3 Free

View in Chrome Web Store Data as of 16 Oct 2026

A comprehensive tool for certificates: Key Pair Generation, CSR Generation, Public Key Derivation, and Inspection.

Users

+17 in 30 days

Rating

0.0 / 5

unchanged in 30 days

Ratings

0 in 30 days

Store rank

#99K

#82K among extensions

Version

1.0.1

updated 7 Jan 2026

Users

monthly, 9 months

Latest, 16 Oct 2026: 65 usersMove the mouse over the chart for any month

Ratings count

monthly, 9 months

Latest, 16 Oct 2026: 0 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About Cert Tool

A powerful and elegant Chrome extension for handling X.509 certificates and cryptographic keys. **Features** 1. Key Pair Generation Generate cryptographic key pairs instantly using the Web Crypto API. - Algorithms: RSA (2048, 4096 bits), ECDSA (P-256, P-384, P-521), and Ed25519. - Standard Formats: Private keys are exported in PKCS#8 and public keys in SPKI. - Save As: Easily download keys with a standard OS save dialog. 2. CSR Generation Create Certificate Signing Requests (CSR) with a user-friendly form. - Customizable DN: Set Common Name, Organization, Country, and more. - SAN Support: Add multiple Subject Alternative Names (DNS, IP, Email, URI). - Flexible Signing: Sign the request using your own private key. 3. Public Key Derivation Extract the public key component from various sources. - Input Types: Supports Private Keys (PKCS#8/PKCS#1), Certificates, or CSRs. - Auto-Detection: Automatically identifies the input type and algorithm. 4. Certificate/CSR Inspector View detailed information about certificates and signing requests. - Comprehensive View: Shows Serial Number, Subject, Issuer, Validity, and Public Key details. - Extension Decoding: Human-readable decoding for SANs, Basic Constraints, Key Usage, and Extended Key Usage (EKU).