Last updated July 4, 2026

Privacy & Cookie Policy

This policy explains what D4Filter collects, why it is used, how advertising and analytics providers may process data, and the choices available to visitors.

Information we process

D4Filter processes only the information needed to operate, protect, and improve the service:

  • Account information: username, display name, email address, date of birth, authentication session data, and a one-way password hash for credentials accounts. D4Filter does not store the plain-text password.
  • Filter information: saved rules, filter names, import codes, build-guide links, public descriptions, votes, comments, and reports submitted through community safety tools.
  • Technical information: request metadata such as IP-derived rate-limit identifiers, browser user agent, error diagnostics, page views, device type, and performance measurements.
  • Local workbench information: drafts and preferences may be stored in the browser so work is not lost between visits.

This information is used to provide accounts and saved filters, publish community pages, prevent abuse, investigate failures, understand aggregate site usage, and maintain the security and reliability of D4Filter.

Cookies and similar technologies

D4Filter and its service providers may use the following categories of browser storage:

Essential
Authentication, security, rate limiting, and user-requested preferences required for the site to function.
Analytics and performance
Aggregate page-use and performance information provided through Vercel Analytics and Speed Insights.
Advertising
Google and its partners may use cookies, web beacons, IP addresses, or other identifiers to deliver, measure, and protect ads.

Browser settings can remove or block cookies, but blocking essential storage can prevent sign-in, saved settings, and other requested features from working.

Google advertising

D4Filter uses Google AdSense. Third-party vendors, including Google, use cookies to serve ads based on a visitor's previous visits to D4Filter or other websites. Google's advertising cookies enable Google and its partners to serve ads based on visits to this site and other sites on the internet. Depending on consent and account settings, advertising may be personalized or non-personalized.

Learn how Google processes information on partner sites in How Google uses information from sites or apps that use its services. Visitors can manage personalized advertising in Google Ads Settings and can review industry opt-out choices at YourAdChoices.

Your privacy and cookie choices

Where required, D4Filter uses Google's certified consent-management platform to ask for and record advertising choices. Visitors in the European Economic Area, United Kingdom, and Switzerland can withdraw consent and see the consent message again by using the control below. Applicable US-state privacy messages and opt-out controls are also managed through Google Privacy & messaging.

Account holders may update profile information from the account page. Requests to access, correct, or delete personal information can be submitted through the contact method below. Rights vary by location and may be subject to identity verification or legal exceptions.

Service providers and public information

D4Filter uses hosting, database, authentication, analytics, performance, and advertising providers to run the service. These providers process information under their own terms and privacy commitments. Public filter pages intentionally display the filter name, description, creator label, rules, comments, and votes selected for publication. Do not publish personal or confidential information in community content.

D4Filter does not sell account profile information. Advertising providers may process identifiers as described above.

Retention, security, and children

Information is retained while needed to operate the service, meet legal obligations, resolve disputes, enforce policies, and maintain backups. Anonymous share links can expire automatically; public content and moderation records may be kept longer when necessary for safety and abuse prevention. Reasonable technical and organizational safeguards are used, but no internet service can guarantee absolute security.

D4Filter is a general-audience fan tool and is not directed to children under 13. If personal information from a child is believed to have been submitted, contact the project so it can be reviewed and removed where appropriate.

Contact and policy changes

Privacy questions or requests can be submitted through the D4Filter project issue tracker. Do not include passwords, filter codes intended to remain private, or sensitive personal data in a public issue.

This policy may be updated as the service, providers, or legal requirements change. Material updates will be reflected by the date at the top of this page.