How to Block a Website with the Hosts File (2026)

The hosts file is one of the simplest ways to block a website on your entire computer — not just in one browser, but in every application that uses the system DNS resolver. Redirect a domain to 0.0.0.0 and requests fail before they leave your machine. No extension required. No subscription.

This guide shows how to block any website on Windows, Mac, and Linux — plus how to unblock mistakes, block multiple domains efficiently, and understand the limitations.

See also: Main editing guide · Block ads with the hosts file

How hosts file blocking works

When your computer tries to connect to facebook.com, it first checks the hosts file. If the file contains:

0.0.0.0    facebook.com

The OS resolves facebook.com to 0.0.0.0 — a non-routable address. The connection fails immediately. The request never reaches Facebook's servers or any DNS server.

This is system-wide blocking — it affects:

• All browsers (Chrome, Firefox, Safari, Edge)
• Desktop applications
• Command-line tools (curl, wget)
• Many Electron apps

It does not affect:

• Apps using hardcoded IP addresses
• Apps using DNS-over-HTTPS that bypass local resolution
• Other devices on your network (blocking is local to one machine)

0.0.0.0 vs 127.0.0.1 — which to use?

Use `0.0.0.0` for blocking. It is the standard in ad-blocking lists like Steven Black's hosts file.

For IPv6-capable applications, also add:

::    facebook.com

Step-by-step: block a website

Windows

1. Open Notepad as administrator (see Windows guide) 2. Open C:\Windows\System32\drivers\etc\hosts 3. Add at the bottom:

# Block Facebook — added 2026-06-11
0.0.0.0    facebook.com
0.0.0.0    www.facebook.com
0.0.0.0    m.facebook.com
0.0.0.0    web.facebook.com

4. Save (Ctrl+S) 5. Flush DNS:

ipconfig /flushdns

macOS

sudo nano /etc/hosts

Add blocking entries, save (Ctrl+O, Enter, Ctrl+X), then:

sudo dscacheutil -flushcache && sudo killall -HUP mDNSResponder

See Mac guide.

Linux / Ubuntu

sudo nano /etc/hosts

Add entries, save, then:

sudo resolvectl flush-caches

See Linux guide · Ubuntu guide

Block multiple websites

Manual list

# === Productivity blocks ===
0.0.0.0    twitter.com
0.0.0.0    www.twitter.com
0.0.0.0    x.com
0.0.0.0    www.x.com
0.0.0.0    reddit.com
0.0.0.0    www.reddit.com
0.0.0.0    old.reddit.com
0.0.0.0    instagram.com
0.0.0.0    www.instagram.com

Import a blocklist

Popular curated lists contain thousands of ad and tracker domains:

Steven Black's unified hosts file:

# macOS/Linux — back up first!
sudo cp /etc/hosts /etc/hosts.backup
curl -s https://raw.githubusercontent.com/StevenBlack/hosts/master/hosts | sudo tee /etc/hosts

Windows (PowerShell as admin):

Copy-Item C:\Windows\System32\drivers\etc\hosts C:\Windows\System32\drivers\etc\hosts.backup
Invoke-WebRequest -Uri "https://raw.githubusercontent.com/StevenBlack/hosts/master/hosts" -OutFile C:\Windows\System32\drivers\etc\hosts
ipconfig /flushdns

For ad-specific blocking see Block ads with the hosts file.

Important: block both www and non-www

A common mistake — blocking only facebook.com but not www.facebook.com:

# Incomplete — www.facebook.com still works!
0.0.0.0    facebook.com

# Complete
0.0.0.0    facebook.com
0.0.0.0    www.facebook.com

Always block both variants. Some sites also use m., mobile., or api. subdomains.

Unblock a website

1. Open the hosts file as administrator 2. Find the blocking lines 3. Either delete them or comment out with #:

# 0.0.0.0    facebook.com
# 0.0.0.0    www.facebook.com

4. Save and flush DNS cache

Verify blocking works

ping test

ping facebook.com

Expected on blocked domain:

PING facebook.com (0.0.0.0): ...

Or "Request timed out" / "Destination host unreachable."

Browser test

Navigate to the blocked site — you should see:

• "This site can't be reached" (Chrome)
• "Unable to connect" (Firefox)
• "Safari Can't Connect to the Server" (Safari)

nslookup

nslookup facebook.com

Should return 0.0.0.0 or 127.0.0.1.

Limitations of hosts file blocking

No wildcards

You cannot write:

0.0.0.0    *.facebook.com   # DOES NOT WORK

Each subdomain needs its own line. For wildcard blocking, use dnsmasq or Pi-hole.

Modern apps use many domains

YouTube, Netflix, and Spotify use dozens of CDN domains. Blocking the main domain often breaks functionality incompletely rather than blocking cleanly.

DNS-over-HTTPS bypass

Browsers with Secure DNS enabled may bypass the hosts file for some lookups:

• Chrome: Settings → Privacy → Security → Use secure DNS → Off (for testing)
• Firefox: Settings → Privacy → DNS over HTTPS → Off

VPN and custom DNS

If your system uses a VPN or custom DNS (1.1.1.1, 8.8.8.8) configured to bypass local resolution, hosts file blocking may not apply to all traffic. Test with ping first.

Mobile apps on the same machine

Most desktop apps respect the hosts file. Some sandboxed apps (macOS App Store apps with network entitlements) may behave differently.

Does not block other devices

Hosts file blocking is per machine. Your phone and tablet are unaffected. For network-wide blocking, use router-level DNS filtering or Pi-hole.

Blocking vs redirecting

Blocking (0.0.0.0) makes the site unreachable. Redirecting sends the domain to a different IP:

# Redirect old-site.com to new server for testing
203.0.113.50    old-site.com

This is not blocking — it is routing. Useful for staging tests. See main guide.

Performance with large blocklists

Blocklists with 100,000+ entries:

• Slightly increase file read time at boot (negligible on modern hardware)
• May slow DNS lookup by microseconds per query
• Can occasionally cause false positives (blocking legitimate CDN domains)

Start with a small manual list. Add curated lists incrementally. Keep a backup.

Best practices

• Comment every block with reason and date
• Back up before importing lists — sudo cp /etc/hosts /etc/hosts.backup
• Block www AND non-www versions
• Test after blocking — verify the site fails AND critical services still work
• Review blocklists — Steven Black's list is maintained but may block domains you need
• Use 0.0.0.0 not 127.0.0.1
• Flush DNS after every change
• Remove blocks when no longer needed — stale blocks cause confusing failures months later

Example: focus mode blocklist

# === Focus mode — weekdays only (manual toggle) ===
# Created: 2026-06-11

0.0.0.0    twitter.com
0.0.0.0    www.twitter.com
0.0.0.0    x.com
0.0.0.0    www.x.com
0.0.0.0    reddit.com
0.0.0.0    www.reddit.com
0.0.0.0    old.reddit.com
0.0.0.0    news.ycombinator.com
0.0.0.0    instagram.com
0.0.0.0    www.instagram.com

Toggle focus mode by commenting/uncommenting the block and flushing DNS.

Blocking streaming and social platforms

Some platforms require blocking multiple related domains for effective blocking:

# Netflix (partial — CDN domains also needed)
0.0.0.0    netflix.com
0.0.0.0    www.netflix.com

# TikTok
0.0.0.0    tiktok.com
0.0.0.0    www.tiktok.com
0.0.0.0    tiktokv.com

Complete blocking of streaming services is difficult because video delivery uses many dynamically named CDN endpoints. Hosts file blocking works best for simple websites with few domains — news sites, forums, and social networks with predictable hostname patterns.

Legal and workplace considerations

Blocking websites on a work machine may violate employer acceptable use policies if it interferes with work-related access. Blocking on a shared family computer affects all users — communicate before deploying large blocklists. The hosts file is a local tool, not network surveillance; it does not log or report blocked attempts.

GUI management with Locahl

Managing hundreds of blocking entries manually is tedious. Locahl lets you enable/disable individual entries without deleting them — useful for toggling focus blocks. Automatic backup and DNS flush included.

Related guides

• Edit host file — all platforms
• Block ads (large lists)
• Windows editing
• Mac editing
• Linux editing
• Syntax reference
• Is editing safe?
• Complete reference

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*Last tested: Windows 11 24H2, macOS 15, Ubuntu 24.04 — June 2026.*