SwitchHosts Not Working? Fix Permissions, DNS Cache, and Hosts Conflicts

Direct answer: When SwitchHosts is not working, the hosts file often did change — but DNS cache, write permissions, or a VPN/DNS blocker is still serving the old IP. Confirm the system hosts file, fix permissions, flush DNS, then disable override tools. If you hit this weekly, a SwitchHosts alternative with apply + flush (like Sleezr) is usually faster than repeating Terminal rituals.

Quick diagnostic order

Work top to bottom — most “SwitchHosts not working” reports stop at step 3.

1. Confirm the hosts file on disk

After switching a profile, open the real file:

• macOS / Linux: /etc/hosts
• Windows: C:\Windows\System32\drivers\etc\hosts

If your SwitchHosts lines are missing, the app never wrote successfully — go to permissions next. If the lines are present but the browser is wrong, skip to DNS flush.

2. Fix “no permission to write” errors

SwitchHosts needs elevation to modify the system hosts file. This is a common GitHub/issue report pattern.

macOS

• Approve the admin prompt when SwitchHosts requests it
• Baseline test: sudo nano /etc/hosts — if that fails, fix OS permissions first
• Related: hosts file permission denied on Mac

Windows

• Run SwitchHosts as Administrator when writing fails
• Confirm antivirus or corporate policy is not locking the hosts file
• Related: edit hosts as administrator

3. Flush DNS (the #1 “hosts say new, browser says old” fix)

SwitchHosts does not automatically flush DNS. After every profile switch:

macOS

sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

Full guide: flush DNS on Mac

Windows (elevated)

ipconfig /flushdns

Guide: flush DNS on Windows

Linux (systemd-resolved example)

sudo resolvectl flush-caches

Guide: flush DNS on Linux

Then hard-refresh or restart the browser.

4. Check VPN and DNS override tools

Even a perfect hosts file loses to:

• AdGuard / NextDNS / Pi-hole
• Cloudflare WARP
• Tailscale MagicDNS
• Corporate VPN split DNS

Disable them temporarily and retest app.test (or your domain). If it works only with the VPN off, adjust that tool — not SwitchHosts.

5. Browser and app caches

Flushing OS DNS ≠ clearing HTTP cache. After flush:

• Hard-refresh the tab
• Try a private window
• Quit and reopen Chrome/Safari/Firefox if needed

Still broken? Deeper checks

• Syntax error in a hosts line (bad IP/domain)
• IPv6 vs IPv4 mismatch (::1 vs 127.0.0.1)
• Hitting a public DNS path that ignores local hosts expectations inside containers/VMs
• Another editor overwrote SwitchHosts output

Mac-focused deep dive: hosts file not working on Mac · etc/hosts not working

When to switch tools

Stay on SwitchHosts if flush + permissions are occasional hiccups.

Consider a SwitchHosts alternative when:

• Teammates forget DNS flush every time
• You want automatic backups before writes
• You need clearer named environments for clients/QA

Sleezr’s loop is Apply → backup → flush on Windows, macOS, and Linux (4.99 € one-time after trial). Comparison: SwitchHosts alternative.

Related

• Hosts file switcher
• Best hosts file managers for Mac
• Alternatives hub

Bottom line

SwitchHosts not working is usually permissions or DNS cache — not a mysterious DNS failure. Fix write access, flush DNS, rule out VPN/DNS blockers. If that dance is your weekly ritual, Sleezr removes the most common failure mode.

Try Sleezr · Read the SwitchHosts vs Sleezr guide