Hey there! Great question—let's break this down by platform, since support for accessing physical device IDs varies wildly these days, mostly due to strict privacy rules and platform restrictions.

Mobile & Tablet Devices #

• Android:
  • For downloaded/installed apps (like React Native/Cordova wrappers), you used to access IMEI or serial numbers, but Android 10+ blocks this for non-system apps unless you hold a restricted permission (which is almost impossible for regular consumer apps). Even if you manage it, users can deny permission, and it'll get flagged in Google Play Store reviews.
  • For web-based apps (accessed via mobile browser), you cannot get any physical device ID. Your best bet is generating a custom UUID and storing it in localStorage or sessionStorage.
• iOS:
  • Apple has long blocked access to UDIDs. The closest you can get is the IDFA (Advertising Identifier), but users can opt out of ad tracking (and you need explicit permission to request it). This isn't a "physical" device ID either—it's resettable by the user.
  • Web apps on iOS have zero access to hardware identifiers; stick to stored custom UUIDs here too.
• Windows Phone/Firefox OS/Tizen:
  • Windows Phone and Firefox OS are essentially discontinued, so you can ignore them for modern development. For Tizen (mostly used on Samsung devices), native apps might have access to a device ID via Tizen APIs, but web-based Tizen apps can't access physical hardware identifiers.

Smart TVs #

• Android TV: Same rules as Android mobile—native apps might get limited access with special permissions, but web apps can't touch physical IDs. Use stored UUIDs for web-based TV apps.
• Tizen OS TV: Native Tizen apps can retrieve a device ID via platform APIs, but web apps (hosted on Tizen) don't have permission to access hardware-level identifiers.
• Web OS (LG): Native WebOS apps can access a device ID through official APIs, but again, web-based apps on WebOS can't get physical device identifiers.

Desktop Browsers (Windows/Mac/Linux) #

Across all desktop browsers, you cannot access any physical device ID (like motherboard serial numbers, CPU IDs, etc.). Browsers are designed to block this for privacy reasons. Your options here are:

• Generate a custom UUID and store it in localStorage (persists across sessions) or sessionStorage (temporary).
• Use browser fingerprinting (generating a hash from browser/OS features like screen resolution, installed fonts, etc.)—but this isn't a physical ID, it can change if the user modifies their browser settings, and it's often blocked by privacy tools like ad blockers or private browsing modes.

Key Takeaway #

Physical device identifiers are largely off-limits for most modern apps, especially web-based ones. Privacy regulations (GDPR, CCPA) and platform policies make it extremely hard (and often risky) to access them. The most reliable, privacy-compliant approach is to generate your own unique identifier when the user first opens the app, store it locally, and use that as your "device ID" for tracking purposes.

内容的提问来源于stack exchange，提问作者Lorena A.