HostProfiles: instant host file switching

Why do we edit the hosts file?

The hosts file (C:\Windows\System32\drivers\etc\hosts) is a plain-text mapping IP → hostname that the OS checks before going to DNS.

Drop a line like 127.0.0.1 myapp.local and the browser stops resolving myapp.local through the internet: it goes straight to localhost.

Common reasons to touch it:

• Pointing a hostname at a staging/dev environment without changing real DNS.
• Reproducing prod issues against a different IP while keeping the URL intact.
• Blocking trackers or distractions at the OS level.
• Switching between QA and production servers that share a domain.

The catch: editing the file by hand is a hassle.

Admin rights, no comments-aware sections, and after every change the OS DNS cache needs flushing or nothing changes.

What HostProfiles does

HostProfiles is a tiny Windows app (C#, .NET Framework 2.0+) that turns hosts management into a profile picker:

• Define multiple profiles, each one a different set of IP → hostname lines.
• Switch with a click: the active profile becomes the live hosts file content.
• DNS cache flush is automatic after a switch, so the new mapping takes effect immediately.
• Edit a profile in a small built-in editor (no external Notepad-as-Admin dance).

It works on Windows 7/8/10 (and later versions too in theory).

Install

1. Open the releases / repo.
2. Grab the zip with the build (no installer — it’s portable).
3. Extract anywhere; a folder ending in ~/HostProfiles/ is fine.
4. Run HostProfiles.exe as Administrator (right-click → Run as administrator). Without elevation it can’t write to hosts and falls back to read-only mode.

To launch it elevated by default: right-click the .exe → Properties → Compatibility → Run this program as an administrator.

Day-to-day use

The main window lists all profiles.

Three actions worth knowing:

• New profile: creates an empty profile. Give it a meaningful name (Dev, Prod, Block-trackers).
• Edit: opens the inline editor; same syntax as a normal hosts file:

# Each line: <IP> <space> <hostname>  [comment after #]
127.0.0.1   myapp.local
192.168.1.50 staging-api.local
0.0.0.0     facebook.com   # block

• Apply (or double-click on the profile): overwrites hosts with that profile’s content and flushes DNS.

The currently active profile stays highlighted. Switching is destructive against hosts: anything written there manually outside the active profile gets overwritten on the next apply.

Treat the active profile as the source of truth.

How I use it

I keep it simple: I define a base profile that’s always loaded (e.g. PROD, that includes the lines Windows ships by default + my permanent custom mappings), and then I have other profiles that are based on different environments (e.g. TEST).

Another useful separation you can do is the following:

• Default: empty / system defaults.
• DEV: base + 127.0.0.1 myapp.local, 127.0.0.1 api.local.
• Block: base + a list of distracting domains pointing to 0.0.0.0.

Switching profile = switching environment in one click + DNS flush.

Things to know

• The app does not merge profiles.

  Apply one and the others are dormant, by design. If two contexts overlap you need a combined profile.

• Running it un-elevated still lets you read/edit profiles, but applying silently fails. The status bar shows whether it has write access.

• On Linux/macOS the equivalent tool is hostctl: different UX (CLI), same idea.