---
title: "crl.apple.com: what it is and what breaks if you block it · Kilobat"
url: "https://kilobat.app/hosts/crl-apple-com"
description: "crl.apple.com and certs.apple.com serve Apple's certificate revocation lists and certificates. Why the Mac connects, and what breaks if you block them."
---

Security and accounts

# crl.apple.com

`crl.apple.com` serves Apple's certificate revocation lists (CRLs), and `certs.apple.com` serves certificates. Apple lists both for certificate validation on every platform.

Run by Apple · Ports: 80 TCP (crl), 80 and 443 TCP (certs) · Checked: 1 November 2026

## Short answer

Apple's hosts for certificate revocation lists and certificates, used to validate the certificates of Apple's services.

Don’t block

Don't block them. The Mac can't fetch Apple's revocation lists or certificates, and Apple services can fail validation.

Matches

`crl.apple.com` `certs.apple.com`

A name with `*.` covers every name under it: `*.push.apple.com` matches `1-courier.push.apple.com`.

## What it serves

Apple's enterprise host list names `crl.apple.com` on port 80 and `certs.apple.com` on ports 80 and 443, both for “Certificate validation”.

The `ocspd` man page says that macOS fetches certificate revocation lists from the network and caches them in `/private/var/db/crls`.

On a Mac, [`trustd`](https://kilobat.app/processes/trustd) evaluates certificates and uses that cache.

## Processes that use it

- [trustd](https://kilobat.app/processes/trustd): Part of macOS. It checks certificates for every app, and asks certificate authorities whether a certificate was revoked. Its connections are small.

## What breaks if you block it

Don’t block

Don't block them. The Mac can't fetch Apple's revocation lists or certificates, and Apple services can fail validation.

What breaks if you block it

- Revoked Apple-issued certificates may not be detected.
- Certificate validation for Apple's services may fail.

With Kilobat Pro and the network filter, you can block a host for every app or for one app: in Connections, select a connection and choose Block. Apple’s own services are never blocked by Kilobat’s [Protection](https://kilobat.app/docs/blocking#protection) lists.

## Notes

CRLs are signed by the certificate authority, so serving them over plain HTTP doesn't let anyone change them.

## Apple’s rules for its hosts

Apple’s list, [Use Apple products on enterprise networks](https://support.apple.com/en-us/101555), says that devices open these connections, not Apple’s servers. Apple services fail any connection that uses HTTPS interception, so a proxy that inspects TLS should leave Apple’s hosts alone.

If a firewall allows hosts by name, allowing `*.apple.com` covers most Apple services, Apple says. A firewall that works only with addresses can allow `17.0.0.0/8` for IPv4, and `2403:300::/32`, `2620:149::/32` and `2a01:b740::/32` for IPv6.

To see which app on your Mac opened a connection to this host, use Kilobat’s Connections tab, or the [agent network log](https://kilobat.app/docs/agents#agent-network-log) for AI agents.

## Sources

- [Apple Support: Use Apple products on enterprise networks](https://support.apple.com/en-us/101555)
- ocspd(1), man page installed with macOS 27.2

Checked on 1 November 2026.

## Related

- [ocsp.apple.com](https://kilobat.app/hosts/ocsp-apple-com): Apple's certificate status (OCSP) servers. The Mac asks them whether an Apple-issued certificate has been revoked.
- [valid.apple.com](https://kilobat.app/hosts/valid-apple-com): An Apple certificate validation host. Apple lists it for every platform, on port 443, with proxy support.
- [ocsp.digicert.com](https://kilobat.app/hosts/digicert-ocsp): DigiCert's certificate status and revocation list hosts. Apple lists them because some of its services use DigiCert certificates.