Automates the hardening and optimization of Firefox on any Linux distribution, using Firefox's Enterprise Policy Engine to inject system-wide configurations. (This script deletes cookies; use at your own risk)

optimize_firefox.sh

#!/bin/bash

# Ensure the script is run as root
if [ "$EUID" -ne 0 ]; then
  echo "Please run as root (sudo)"
  exit 1
fi

# Define the target directory for Firefox system-wide policies
POLICY_DIR="/etc/firefox/policies"
POLICY_FILE="$POLICY_DIR/policies.json"

# Create the directory if it doesn't exist
if [ ! -d "$POLICY_DIR" ]; then
  echo "Creating policy directory..."
  mkdir -p "$POLICY_DIR"
fi

echo "Applying uBlock, Telemetry blocking, and Fastfox optimizations..."

# Python script to safely parse and merge JSON
python3 - <<EOF
import json
import os
import sys

policy_file = '$POLICY_FILE'

# --- 1. EXTENSIONS (uBlock Origin) ---
ublock_id = "uBlock0@raymondhill.net"
ublock_settings = {
    "install_url": "https://addons.mozilla.org/firefox/downloads/latest/ublock-origin/latest.xpi",
    "installation_mode": "force_installed"
}

# --- 2. BASE PRIVACY & TELEMETRY ---
base_policies = {
    "DisableTelemetry": True,
    "DisableFirefoxStudies": True,
    "DisablePocket": True,
    "DisableFeedbackCommands": True,
    "SanitizeOnShutdown": {
        "Cache": False,
        "Cookies": False,
        "History": False,
        "Sessions": False,
        "Downloads": True,
        "FormData": True,
        "OfflineApps": True
    }
}

# --- 3. FASTFOX & PERFORMANCE PREFERENCES ---
# Mapped directly from your Fastfox.js file
fastfox_prefs = {
    # General Rendering
    "gfx.content.skia-font-cache-size": 32,
    "gfx.webrender.all": True,
    "gfx.webrender.layer-compositor": True,
    "gfx.canvas.accelerated.cache-items": 32768,
    "gfx.canvas.accelerated.cache-size": 4096,
    "webgl.max-size": 16384,
    
    # Disk Cache (Disabled in favor of RAM)
    "browser.cache.disk.enable": False,
    
    # Memory Cache (Optimized for 8GB+ RAM systems per Fastfox)
    "browser.cache.memory.capacity": 131072, # 128MB fixed RAM cache
    "browser.cache.memory.max_entry_size": 20480,
    "browser.sessionhistory.max_total_viewers": 4,
    "browser.sessionstore.max_tabs_undo": 10,
    
    # Media Cache
    "media.memory_cache_max_size": 262144,
    "media.memory_caches_combined_limit_kb": 1048576,
    "media.cache_readahead_limit": 600,
    "media.cache_resume_threshold": 300,
    
    # Image Cache
    "image.cache.size": 10485760,
    "image.mem.decode_bytes_at_a_time": 65536,
    
    # Network / Connection Tuning
    "network.http.max-connections": 1800,
    "network.http.max-persistent-connections-per-server": 10,
    "network.http.max-urgent-start-excessive-connections-per-host": 5,
    "network.http.request.max-start-delay": 5,
    "network.http.pacing.requests.enabled": False,
    "network.dnsCacheEntries": 10000,
    "network.dnsCacheExpiration": 3600,
    "network.ssl_tokens_cache_capacity": 10240,
    
    # Speculative Loading (Privacy/Bandwidth Hardening)
    "network.http.speculative-parallel-limit": 0,
    "network.dns.disablePrefetch": True,
    "network.dns.disablePrefetchFromHTTPS": True,
    "browser.urlbar.speculativeConnect.enabled": False,
    "browser.places.speculativeConnect.enabled": False,
    "network.prefetch-next": False,
    
    # QoL
    "sidebar.revamp": False
}

# --- LOGIC: MERGE INTO JSON ---

data = {}
# Load existing
if os.path.exists(policy_file):
    try:
        with open(policy_file, 'r') as f:
            content = f.read().strip()
            if content:
                data = json.loads(content)
    except Exception:
        data = {}

# Ensure structure
if 'policies' not in data:
    data['policies'] = {}
if 'ExtensionSettings' not in data['policies']:
    data['policies']['ExtensionSettings'] = {}
if 'Preferences' not in data['policies']:
    data['policies']['Preferences'] = {}

# Apply Base Policies
for key, value in base_policies.items():
    data['policies'][key] = value

# Apply uBlock
data['policies']['ExtensionSettings'][ublock_id] = ublock_settings

# Apply Fastfox Preferences
# We merge these into the 'Preferences' policy object
for key, value in fastfox_prefs.items():
    data['policies']['Preferences'][key] = value

# Write to file
try:
    with open(policy_file, 'w') as f:
        json.dump(data, f, indent=2)
    print("Success: Fastfox configuration applied to system-wide policies.")
except OSError as e:
    print("Error writing file: " + str(e))
    sys.exit(1)
EOF

if [ $? -eq 0 ]; then
    echo "Done. Restart Firefox to see changes."
else
    echo "Failed."
    exit 1
fi

Run with one command.

curl -fsSL https://gist.githubusercontent.com/nukhes/2070194987a4d71c5a2bad7574e79630/raw | sudo bash