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Trusted file extension guides and opening help from the original project since 2008.

How to open .CER files on Windows

To open .CER files on Windows, right-click the .cer file and choose open with..

Step-by-step instructions

  1. Right-click the .CER file and choose Open with.
  2. Select a trusted Windows app that supports .CER files.

Recommended software

  • VS Code
  • Notepad++/TextEdit
  • jq (CLI)

Alternative methods

  • Open .CER in a browser-based viewer if desktop apps fail.
  • Try opening .CER on Windows with a secondary app to rule out app-specific issues.
  • Convert .CER only with trusted tools when direct opening is not possible.

Common issues

.CER file does not open

This usually means the required app is missing or the .CER file is incomplete.

  1. Install or update a compatible application.
  2. Verify the file came from a trusted source and was fully downloaded.
  3. Try opening the file in an alternative app on another platform.

Security note

Only open .CER files from trusted senders.

Back to .CER extension page