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How to open .CER files on iOS

To open .CER files on iOS, open the .cer file from files and tap share..

Step-by-step instructions

  1. Open the .CER file from Files and tap Share.
  2. Send it to a compatible iOS app if Quick Look cannot preview it.

Recommended software

  • Textastic
  • Kodex
  • Files app

Alternative methods

  • Open .CER in a browser-based viewer if desktop apps fail.
  • Try opening .CER on iOS 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