Your data is not the product.

Last updated: 19 April 2026

TL;DR

• We collect nothing at all unless you check a specific opt-in box during first-run setup.
• If you opt in: anonymous event names, your D4 resolution, and an install-level UUID we generate. That's the whole list.
• We never collect your Battle.net handle, character names, in-game behavior, build URLs, Windows username, IP address, or anything that could identify you.
• You can turn it off anytime from the app's Settings menu, and all future events stop immediately.

What runs locally, never sent anywhere

• Your calibration data (stored in %LOCALAPPDATA%\D4BuildOverlay\)
• Build data you load (parsed from URLs you paste)
• Game window detection — we look for a window named "Diablo IV" on your machine. Nothing leaves your computer.
• The telemetry event log (if opt-in is off, it still logs locally but is never transmitted; if it's on, events ship to our endpoint as described below)

What we collect when you opt in

The desktop app POSTs small JSON records to a Cloudflare Worker we run at our Cloudflare Worker (subdomain varies per deploy — see our GitHub for the live URL). Each record contains:

• event — a fixed string from an allowlist. The full list as of this version: app_launched, first_run_completed, build_loaded, calibration_completed, overlay_activated, overlay_deactivated. The Worker rejects any other event name at the edge — we cannot even accidentally log anything outside this list.
• install_id — a random UUID we generated on your first launch and stored in your local settings file. It is never correlated with any other identifier. If you reinstall, you get a new one.
• ts — the UTC timestamp of the event.
• app_version — e.g. 0.1.0.
• props — small metadata per event. Examples: the parser source (Mobalytics / Maxroll), the D4 class name (Paladin), your resolution (2560x1600), and paragon/skill-point counts for the build you loaded. These props are sanitized against the allowlist before storage.

We run ad-hoc SQL queries against this data to answer questions like "how many people complete calibration after loading a build" or "what resolutions are alpha testers running." That's it.

What we explicitly do not collect

• Your IP address. Cloudflare terminates TLS; the Worker is coded to never read the cf-connecting-ip header.
• Your Battle.net BattleTag or any account identifier.
• Character names, class levels, item names, gear, trades, or anything about your actual in-game activity.
• The URLs of builds you paste. Build URLs are user-authored content and can contain identifying info; we never send them.
• Your Windows username or hostname.
• Any cookies or browser-style tracking. There are no cookies anywhere — this is a desktop app.

Who can see this data

The Cloudflare D1 database is accessible only to the project maintainers via the Cloudflare dashboard / wrangler CLI. We do not sell, share, or license it to third parties. If D4 Build Overlay ever gets acquired, this policy travels with the dataset — any future owner inherits the commitment or must ask you to opt in again.

Retention

Events are kept for 90 days, then automatically deleted from D1. We do not currently aggregate them into longer-lived summaries, but may in future (e.g. a per-month install count). If we do, aggregates will contain no per-install identifiers.

Your rights

• Opt out anytime. Settings → toggle off analytics. No more events are sent from the moment you save.
• Delete your data. Email privacy@db4builds.com with your install_id (visible in Settings → About) and we'll purge all rows with that ID within 7 days.
• Uninstall. Uninstalling the app removes your local settings file (including the install_id). After that, events in the backend are orphan UUIDs with no way to link back to you.
• See what we have. Same email address — we'll reply with a CSV of every row associated with your install_id.

Children

D4 Build Overlay is not directed at children under 13. Don't use the app if you are under 13. If you tell us that data associated with a minor ended up in our telemetry, we'll delete it immediately.

Changes to this policy

If we change what events are collected or how data is used, we'll bump the "Last updated" date at the top of this page and require a fresh opt-in in the app (the consent checkbox will reappear). Alpha users will also get an in-app notice before any such change takes effect.

Contact

Privacy questions: privacy@db4builds.com
General support: support@db4builds.com

D4 Build Overlay is a fan-made tool. Not affiliated with, endorsed by, or sponsored by Blizzard Entertainment, Inc. See our terms of service for the full disclaimer.