Get Device UDID

A UDID is a 40-character hexadecimal string that uniquely identifies every iPhone, iPad or iPod touch. Apple Developer accounts need it to register devices for Ad Hoc provisioning — without it, your test build won't install.

There are three ways to get your device UDID. This page uses the Safari configuration-profile method — it's the fastest, doesn't need a Mac, iTunes, or any third-party app, and it's the exact same mechanism Apple Developer uses for device enrollment.

1. Open buildstud.io/tools/mobile/udid in Safari on your iPhone or iPad. Chrome, Firefox, Edge or any other browser won't work — only Safari can install configuration profiles.
2. Tap "Get UDID". Safari will ask if you want to download a configuration profile. Tap Allow.
3. Open Settings. Go to Settings → General → VPN & Device Management (on iOS 15 and later), or Settings → Profile Downloaded at the top of Settings (on older versions).
4. Tap the BuildStudio UDID profile → Install. Enter your passcode. Tap Install again when prompted, then Done.
5. Return to this page. Your 40-character UDID will appear. Tap it to copy.

That's it. The profile doesn't change anything on your device — it just exposes the UDID to the browser. You can remove it anytime from Settings → VPN & Device Management.

UDID stands for Unique Device Identifier. Apple assigns every iPhone, iPad, iPod touch, Apple Watch and Apple TV a 40-hex-character identifier at the factory. The UDID never changes for the lifetime of the device — factory resets, OS updates, SIM swaps and Apple ID changes don't alter it.

Format: 8-4-4-4-12 or 25-character with hyphens on newer devices. Example: 00008110-000109D01AEB801E (iPhone 14+) or a1b2c3d4e5f67890abcdef1234567890abcdef12 (older devices, 40 chars no hyphens).

UDIDs aren't reachable to regular apps — iOS 7 removed the public UDID API to stop ad networks from using it as a tracking cookie. Today apps see a per-app Vendor Identifier (IDFV) or the opt-in Advertising Identifier (IDFA) instead. Only Apple Developer provisioning workflows, Apple Configurator, iTunes/Finder and iOS Configuration Profiles can read the actual UDID.

Apple's app distribution model has three tiers:

• App Store — anyone can install, but every build goes through Apple review (1-3 days, can be rejected).
• TestFlight — pre-release testing. Up to 10,000 external testers by email invite. Still requires Apple review for the first build.
• Ad Hoc distribution — skip the App Store entirely. Install a signed .ipa directly on registered devices, no review. Up to 100 devices per year per Apple Developer account, per device type (iPhone, iPad, Apple Watch, Apple TV, Mac).

Ad Hoc needs every tester's UDID registered in the Apple Developer portal, then included in the app's provisioning profile. Miss a device and that iPhone can't install the build — the signature check rejects it.

Typical workflow:

1. Tester finds their UDID (this tool).
2. Tester sends UDID to developer.
3. Developer adds UDID at developer.apple.com/account/resources/devices.
4. Developer regenerates provisioning profile, rebuilds the app.
5. Developer distributes the signed .ipa to tester (via BuildStudio Distribute, Firebase App Distribution, or direct install).

BuildStudio's data shows Indian developers account for the vast majority of UDID queries globally. A few reasons:

• Apple Developer costs $99/year (≈ ₹8,600) — significant for student developers, freelancers, and bootstrapped founders. Paying once and stretching the 100-device Ad Hoc quota matters more.
• Mac ownership is lower in India — the traditional UDID workflows (Finder, iTunes, Xcode) require a Mac. Safari profile-based UDID extraction lets Windows and Linux devs work without one.
• Thriving iOS freelance + agency ecosystem — more developers distributing builds to more clients for review, especially pre-App-Store launch, which means more UDIDs collected per project.
• Strong internal/enterprise app culture — Indian IT services firms distribute custom iOS tools to enterprise clients via Ad Hoc (not via Apple Business Manager), driving UDID collection.

The content on this page works for any English-speaking iOS developer — the instructions are identical — but BuildStudio's core audience skews heavily to India and our tooling (QR-share for distribution, no-Mac-required UDID) reflects that.

Short answer: yes, if you're sharing with an Apple Developer you trust. Longer answer:

• A UDID alone cannot unlock your phone, access your Apple ID, install apps without your consent, track your location, or do anything destructive.
• A UDID is only useful to someone with an active Apple Developer account — they can register your device for Ad Hoc / Development builds, which still need your explicit permission to install (you tap "Install" in Settings).
• iOS 7 (2013) removed the public UDID API precisely to stop advertisers and analytics SDKs from fingerprinting users by UDID. Today, apps see a per-app vendor ID that resets if you uninstall every app from that vendor. So a leaked UDID has essentially no tracking use outside the Apple Developer ecosystem.
• BuildStudio's Safari profile method doesn't send the UDID anywhere — it's displayed in your browser for you to copy and share manually.

The only real risk is installing a malicious configuration profile that claims to be a UDID reader but actually configures a rogue VPN or certificate. Only install profiles from trusted sources. Review the profile contents in Settings before installing, and remove it after you've copied the UDID.