certifi

Common errors

Warnings

Install

Install compatibility verified last tested: 2026-05-12

Imports

• certifi
  wrong

  from certifi import old_where; old_where()

  correct

  import certifi
  certifi.where()

  certifi.old_where() was kept as an alias of certifi.where() after 1024-bit root removal but should no longer be used; call certifi.where() directly.

• certifi.where

  import certifi
  path = certifi.where()  # returns str path to cacert.pem

  certifi.where() is the entire public API. It returns a string file path, not a file object or a list of certs.

Quickstart stale last tested: 2026-04-23

Use certifi.where() with requests, urllib3, and the stdlib ssl module to pin SSL verification to the bundled Mozilla CA store.

import certifi
import requests
import urllib3
import ssl

# 1. Print the path to the bundled CA bundle
print(certifi.where())  # e.g. /path/to/certifi/cacert.pem

# 2. Pass explicitly to requests (requests uses certifi automatically,
#    but being explicit avoids surprises when REQUESTS_CA_BUNDLE is set)
response = requests.get("https://httpbin.org/get", verify=certifi.where())
print(response.status_code)

# 3. Pass to urllib3 directly
http = urllib3.PoolManager(ca_certs=certifi.where())
r = http.request("GET", "https://httpbin.org/get")
print(r.status)

# 4. Pass to the stdlib ssl module
ctx = ssl.create_default_context(cafile=certifi.where())
print(ctx)