Quantcast Opt Out Guide: Control Browser Advertising Data

To opt out of Quantcast browser advertising data, open its Privacy Choices page in every browser profile you use. Quantcast offers a cookie-based choice and a cookieless choice based on an IP address and device information. Both are browser-specific. Use Quantcast's Data Subject Rights page for access, correction, deletion, or portability when a browser-level advertising preference is not enough. Mobile apps, streaming devices, matched-email advertising, and marketing email use separate controls.

Use a free exposure scan for visible records, then continue through the opt-out guide hub for the providers and identifiers connected to your exposure.

Quantcast opt-out facts at a glance

Source basis: Quantcast's current Privacy Choices and Data Subject Rights pages were checked August 15, 2026. No choice or personal request was submitted.

Choose cookie-based or cookieless control

The cookie-based method stores an opt-out cookie that Quantcast can read later in the same browser profile. The cookieless method associates the choice with an identifier based on the device's IP address and other device information. A changed network or device state can create another identifier. Neither web method controls advertising IDs inside apps, television platforms, matched-email advertising, or marketing email subscriptions.

Read what a data broker is to understand why a browser preference and a deletion request are not interchangeable. A browser opt-out stops covered interest-based advertising processing; deletion is a separate legal request with its own grounds and verification.

Before setting the Quantcast preference

• Inventory every browser profile and device that you actively use.
• Decide whether your browser allows the opt-out cookie or requires the cookieless method.
• Use device privacy settings separately for apps, televisions, streaming boxes, and game systems.
• Use the rights form for access or deletion and provide only the information needed to match and verify your request.

How to opt out of Quantcast

1. Open Quantcast Privacy Choices in the browser profile you want to control.
2. Choose the displayed cookie-based or cookieless opt-out and confirm the page records the preference.
3. Repeat the choice in every other browser profile and device browser.
4. Enable Global Privacy Control where appropriate, and set separate mobile or streaming-device advertising preferences.
5. Use Data Subject Rights for access, correction, deletion, or portability, then save the case reference.

Timing and verification

Quantcast says an IP-based cookieless identifier is used for no more than 30 days before a new, unlinked identifier is created. Processing tied to the prior identifier ceases within 30 days for ordinary purposes and within 60 days for security and anti-fraud. Those periods describe the cookieless identifier, not a universal deadline for every access or deletion request.

Use the evidence method in how to remove yourself from data brokers and list every browser and identifier separately in the data broker opt-out list.

Choose the browser method based on what the browser can actually store. If cookies are allowed, the opt-out cookie gives Quantcast a stable signal in that profile until it is removed or blocked. If cookies are unavailable, the cookieless method uses the network and device-derived identifier described by Quantcast. Neither method follows you reliably to another browser profile, and the cookieless identifier can change when the device moves between home, office, mobile, or privacy-relay networks.

Do not confuse Quantcast's browser choice with the consent banner on every publisher site. Quantcast says its opt-out does not change selections made through a site's Consent Management Platform. If a publisher presents its own purposes and vendor controls, review those settings separately. Likewise, marketing email preferences are handled through the corporate communication route, while email-based matched advertising may require a participating-industry identifier tool or a direct rights request.

For mobile apps, televisions, streaming boxes, and game platforms, use the device or application advertising controls because the browser mechanism cannot read identifiers across those environments. Keep a simple device list with the date each choice was set. When requesting deletion, identify the relevant browser, device, or account context without guessing at technical identifiers. A written provider response and a later check are stronger evidence than the continued presence of generic ads, which can appear even after targeted advertising stops.

Use a private checklist to record the method selected on each browser and device. Include the date, browser profile, network context for a cookieless choice, and whether a separate rights request was filed. Revisit the checklist after clearing cookies, changing networks, replacing a device, or resetting an advertising identifier, since any of those events can change which signal Quantcast is able to recognize. Store any confirmation or case number beside the corresponding browser, device, or rights-request entry.

Why the Quantcast choice can need renewal

Deleting or blocking the opt-out cookie removes the cookie-based signal. A different browser or device needs its own preference. The cookieless identifier can change when the IP address or other device information changes. Repeat the check after cookie clearing, new browser profiles, changed networks, or replacement devices.

The Dstillery opt-out guide and Datonics opt-out guide explain other browser and advertising-ID controls. Compare recurring support in the service comparison hub if you cannot maintain repeated checks manually.

Quantcast opt-out FAQ

Does one Quantcast opt-out cover every device?

No. Browser choices are profile-specific, and apps or streaming devices use their own advertising settings.

What is the cookieless Quantcast opt-out?

It stores the preference against an identifier derived from the device's IP address and other information when cookies are unavailable.

Does Quantcast honor Global Privacy Control?

Quantcast says it honors GPC for U.S. data subjects. Enable it in every browser profile you use.

Is opting out the same as deleting personal data?

No. The browser preference controls covered advertising processing. Submit a separate data-subject request when deletion is available and intended.