Security utilities

Local Certificate Decoder for Mac and iOS

Decode certificate contents for inspection and troubleshooting. Blissum keeps this utility local on macOS, iPhone, and iPad so you do not have to paste code, tokens, certificates, URLs, or private text into random online tools.

A private alternative to online x.509 certificate decoder tools

Paste a PEM certificate or base64 DER certificate and inspect fields such as subject, issuer, serial number, validity dates, signature algorithm, public key, and extension count. Blissum parses the certificate locally and presents both a structured summary and readable result cards. It is useful for TLS troubleshooting, certificate reviews, and security checks where uploading certificate material to a website is not acceptable.

Blissum groups everyday code, text, data, and web utilities into one local app for Mac, iPhone, and iPad, which is especially useful where iOS has fewer native developer-tool options.

Useful for

This page intentionally covers the practical ways people describe the same workflow, especially when they want a native, local, or offline option instead of a web-based tool.

Use Certificate Decoder locally in Blissum

Download Blissum when you want this utility alongside other local developer tools for text, code, data, web, and security workflows on macOS, iPhone, and iPad.