Postman SSL Error: Self Signed Certificate

How to fix it

Try these in order — the most common fix is first.

1. 1. Add your CA certificate (preferred)

   Copy steps
   1. Settings (gear icon) > Settings > Certificates
   2. Turn on the CA certificates toggle and select your PEM file (one file can hold several CAs)
   Did this fix it? Yes No

2. 2. Turn off verification temporarily

   Copy steps
   1. Open the request's Settings tab and switch 'Enable SSL certificate verification' to OFF, then resend
   2. To apply it globally use the General tab in Postman settings; turn it back on afterwards
   Did this fix it? Yes No

3. 3. Add a client certificate for mutual TLS

   Copy steps
   1. Settings > Certificates > Add Certificate
   2. Enter the host without protocol (wildcards like *.example.com work), optional port (default 443), the CRT and KEY or PFX file, passphrase, then Add
   Did this fix it? Yes No

4. 4. Inspect the problem

   1. Hover over Network in the response pane for certificate details, or read the Console
   Did this fix it? Yes No

Symptoms

Request fails with 'SSL Error: Self signed certificate', 'unable to verify the first certificate' or similar.

Why it happens

• Server uses a self-signed or internal CA certificate
• Corporate TLS inspection proxy re-signing traffic
• Missing or expired intermediate certificate
• Server requires a client certificate (mutual TLS)

This guide also covers

• postman ssl error self signed certificate
• postman unable to verify the first certificate
• postman ssl certificate verification

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