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PEM X.509 Certificate Viewer

Paste one or more public certificates to inspect their structure and chain order locally in your browser without network validation.

  • Up to 20 certificates
  • SHA-256 fingerprint
  • No upload
Online tool

Try the tool

Add your data, choose the settings, and get the result.

PEM certificates

Result

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Your data stays here

Text and selected files are processed in the current browser and are not sent to a server to produce the result.

Reviewed: 2026-07-17
01

How to use it

  1. 1

    Paste PEM CERTIFICATE blocks.

  2. 2

    Run the local inspection.

  3. 3

    Review subject, issuer, validity, SANs, and chain order.

02

What the tool can do

  • Parses bounded DER/ASN.1 X.509 certificate structures.
  • Shows serial, key and signature algorithms, Basic Constraints, and SANs.
  • Calculates SHA-256 fingerprints through Web Crypto.
03

Common use cases

  • Inspect a public certificate before installation.
  • Review SANs and validity dates.
  • Compare a SHA-256 fingerprint offline.
04

How it works inside

Input is bounded to 1,000,000 characters, 20 certificates, and 256,000 DER bytes per certificate.

The result is an inspection, not proof that a certificate is trusted.

05

Questions and answers

Is browser trust verified?

No. The tool does not use the system trust store or make network requests.

Can I paste a private key?

No. Private keys are explicitly rejected and should not be submitted to inspection tools.