What is Do Not Track (DNT)?

Do Not Track (DNT) is a web browser setting that requests that websites and online services not track your browsing activity. When enabled, your browser sends a DNT header with value "1" to every website you visit, signaling your preference for privacy.

The DNT header was introduced as a way to give users more control over their online privacy without requiring technical knowledge. However, honoring DNT is voluntary—websites are not legally required to respect it (except in specific jurisdictions like California under CalOPPA).

How DNT Works

1. User Enables DNT: You enable DNT in your browser settings
2. Browser Sends Header: Your browser includes "DNT: 1" in all HTTP requests
3. Website Receives Signal: The website's server sees the DNT header
4. Website Responds: The website can optionally send a "Tk" (Tracking Status) response header indicating how it handles DNT
5. Website Decision: The website decides whether to honor the DNT request

The Tk (Tracking Status) Response Header

Websites that respect DNT can send a Tk response header to communicate their tracking status. Here are the possible values:

Current State of DNT

Despite its good intentions, DNT has had limited adoption and effectiveness:

• Voluntary Compliance: Most websites ignore DNT because it's not legally enforceable
• Browser Support Declining: Some browsers have removed or deprecated DNT support
• Industry Resistance: Ad networks and data brokers have largely ignored DNT
• Ambiguous Standard: Lack of clear definition of what "tracking" means
• Paradoxical Effect: DNT can actually make you more identifiable (fingerprinting)

Legal Requirements for DNT

California - CalOPPA

California's Online Privacy Protection Act (CalOPPA) requires websites to disclose how they respond to DNT signals. However, it doesn't require them to actually honor DNT—just disclose their practices.

European Union - GDPR

While GDPR doesn't specifically mention DNT, it requires consent for non-essential tracking. A DNT signal could be interpreted as withdrawing consent, but this is not explicitly stated in the regulation.

How to Enable DNT in Different Browsers

Better Alternatives to DNT

1. Global Privacy Control (GPC)

GPC is a newer standard that legally enforceable under privacy laws like CCPA and GDPR. It works similarly to DNT but has legal backing.

2. Browser Privacy Features

• Firefox Enhanced Tracking Protection: Blocks trackers by default
• Safari Intelligent Tracking Prevention: Limits cross-site tracking
• Brave Shields: Blocks ads and trackers automatically

3. Privacy Extensions

• uBlock Origin - Ad and tracker blocker
• Privacy Badger - Learns to block trackers
• DuckDuckGo Privacy Essentials - Comprehensive privacy protection
• Ghostery - Tracker blocker and privacy dashboard

4. VPN and Privacy-Focused Browsers

• Use a VPN to mask your IP address
• Consider privacy-focused browsers like Brave or Tor

Implementing DNT Support on Your Website

If you want to respect user privacy and honor DNT signals:

1. Detect the DNT Header

Check for the DNT header in incoming requests:

// JavaScript (server-side, e.g., Node.js)
if (req.headers['dnt'] === '1') {
    // User has DNT enabled
    // Disable tracking scripts
}

# Python (Flask)
from flask import request
if request.headers.get('DNT') == '1':
    # Disable tracking

2. Send the Tk Response Header

Indicate your tracking status:

# Python (Flask)
@app.after_request
def add_tracking_status(response):
    if request.headers.get('DNT') == '1':
        response.headers['Tk'] = '!'  # No tracking
    return response

3. Disable Tracking Scripts

Conditionally load analytics and advertising scripts based on DNT status.

4. Update Your Privacy Policy

Clearly state how your website handles DNT signals.