What Is Do Not Track (DNT)? How to Set It Up and Its Real Effectiveness

What Is Do Not Track (DNT)?

Do Not Track (DNT) is an HTTP header that lets your web browser signal to websites that you prefer not to be tracked. It was developed following a proposal by the U.S. Federal Trade Commission (FTC) in 2009 and was implemented in major browsers around 2011.

When DNT is enabled, the browser adds a DNT: 1 header to every HTTP request. Websites are expected to read this header and refrain from tracking the user.

How DNT Works

The mechanism behind DNT is straightforward:

  1. The user enables DNT in their browser settings
  2. The browser adds a DNT: 1 header to all HTTP requests
  3. The website receives this header
  4. The website honors the header and refrains from tracking (voluntary)

The Request Information section on Kakunin-san shows whether your browser is sending the DNT header. It's also evaluated in the Security Score under the Do Not Track setting.

How to Enable DNT in Each Browser

Chrome

  1. Open Settings (three-dot menu at top right → Settings)
  2. Click "Privacy and security"
  3. Click "Third-party cookies"
  4. Enable "Send a 'Do Not Track' request with your browsing traffic"

Firefox

  1. Open Settings (hamburger menu → Settings)
  2. Click "Privacy & Security"
  3. Under "Send websites a 'Do Not Track' signal," select "Always"

Safari

Since Safari 12.1, the DNT feature has been removed. Apple cited the risk of DNT being used as a fingerprinting vector and chose to focus on Intelligent Tracking Prevention (ITP) instead.

Edge

  1. Open Settings (three-dot menu at top right → Settings)
  2. Click "Privacy, search, and services"
  3. Enable "Send 'Do Not Track' requests"

Limitations and Reality of DNT

Unfortunately, DNT has significant limitations.

No Legal Enforcement

DNT is merely a request — websites have no legal obligation to honor it. In practice, most ad networks and tracking services simply ignore the DNT header.

Low Adoption Rate

The W3C (World Wide Web Consortium) attempted to standardize DNT but failed to reach industry consensus and abandoned the effort in 2019. The vast majority of major advertising platforms do not support DNT.

Can Become a Fingerprinting Vector

Because only a minority of users enable DNT, the setting itself can be used as a component of browser fingerprinting. This is one of the reasons Apple removed DNT from Safari.

Alternatives to DNT

Rather than relying on DNT alone, combining the following measures is far more effective.

Global Privacy Control (GPC)

GPC is emerging as the successor to DNT. Unlike DNT, GPC functions as an exercise of legal rights under laws like California's CCPA and the EU's GDPR, giving it stronger legal backing. Firefox, Brave, and the DuckDuckGo browser support GPC.

Tracker Blockers

Extensions like uBlock Origin and Privacy Badger don't just "ask" — they technically block trackers. This makes them far more effective than DNT.

Browser Tracking Protection

  • Firefox: Enhanced Tracking Protection
  • Safari: Intelligent Tracking Prevention (ITP)
  • Brave: Shields (ad and tracker blocking)

Additional Measures

Should You Still Enable DNT?

Its effectiveness is limited, but enabling DNT still has value. Some websites and services do honor it, and it serves as a declaration of your privacy preferences. In regions with applicable laws, combining DNT with GPC can provide legal protection.

Check your DNT status on Kakunin-san's Security Score, and combine it with other privacy measures for comprehensive protection.