Skip to content

How-To: Certificate and Proxy Diagnostics

Use this page when HTTPS inspection is not working as expected.

Most common symptom:

If you can see this, traffic is not going through mitmproxy.

  1. Open Settings > Security.
  2. Reinstall/recheck certificate.
  3. Turn monitor ON.
  4. Confirm proxy ON.
  5. Test browsing again.
Certificate and proxy diagnostics flow

Visual Checkpoints

Certificate status panel
Monitor and proxy status controls
Live traffic stream validation

URL to Use During Certificate Bootstrap

Use:

  • http://mitm.it

Do not use:

  • https://mitm.it

Terminal Validation (Optional)

Use these checks only if UI troubleshooting is not enough.

Check local certificate files:

ls -la ~/.mitmproxy

Check listener:

lsof -iTCP:8080 -sTCP:LISTEN

Check macOS proxy state:

scutil --proxy

Troubleshooting Matrix

Symptom Most likely cause First action
Browser shows cert warning Certificate not trusted Reinstall/retrust certificate
Monitor ON but no stream Proxy not active Verify proxy ON in Live Threats
No listener on :8080 Monitor process not ready Restart monitor and retest
Works then stops randomly Local proxy state drift Toggle monitor OFF/ON and recheck

When to Escalate

Escalate if the same issue repeats after full reinstall/retrust and monitor restart.

Include in report:

  • OS and version,
  • exact symptom,
  • screenshot of status pills,
  • output of listener check.