---
title: "download.developer.apple.com: what it is and what breaks if you block it · Kilobat"
url: "https://kilobat.app/hosts/download-developer-apple-com"
description: "download.developer.apple.com and devimages-cdn.apple.com serve Xcode's downloadable components, such as platforms and simulators. What breaks if you block them."
---

Updates and downloads

# download.developer.apple.com

`download.developer.apple.com` and `devimages-cdn.apple.com` serve Xcode's downloadable components. Apple lists both for macOS, on ports 80 and 443.

Run by Apple · Ports: 80 and 443 TCP · Checked: 1 November 2026

## Short answer

Apple's hosts for Xcode's downloadable components.

Safe to block

Safe to block if you don't use Xcode. If you do, Xcode can't download the components it needs.

Matches

`download.developer.apple.com` `devimages-cdn.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 both in its Apps and additional content section, for “Xcode downloadable components”.

Xcode components, such as platform support and simulators, are large. Downloading one can be several gigabytes.

Apple doesn't say which process does the download.

## What breaks if you block it

Safe to block

Safe to block if you don't use Xcode. If you do, Xcode can't download the components it needs.

What breaks if you block it

- Xcode can't download platform support, simulators and other components.

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

Download Xcode components on your usual network. They are among the largest downloads on a developer's Mac.

## 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)

Checked on 1 November 2026.

## Related

- [idmsa.apple.com](https://kilobat.app/hosts/idmsa-apple-com): Apple's Apple Account authentication hosts. Signing in to iCloud, the App Store and Xcode needs them.