FAQ

FAQ

Is a wrong detection a DeviceDetector.NET bug or a rules issue?

First check whether the upstream PHP project gets the same result for the same UA (e.g. via their online demo/tests, or by running the PHP library directly). Two cases:

• PHP also gets it wrong → it's a rules issue; report it upstream at matomo-org/device-detector/issues. DeviceDetector.NET will inherit the fix on the next data sync.
• PHP gets it right, .NET doesn't → it's a porting bug in this repository; please open an issue here with the User-Agent string and the expected vs. actual result.

Why does GetOs() / GetClient() return an empty/unsuccessful result?

Make sure you called dd.Parse() before reading any getter — nothing is parsed until Parse() runs. Also check ParseResult<T>.Success before touching .Match; an unmatched UA returns Success == false with Match == null.

Why do version numbers look truncated (e.g. "16" instead of "16.0.3")?

By default, versions are truncated to VERSION_TRUNCATION_MINOR (major.minor). Call this once, before parsing:

DeviceDetector.SetVersionTruncation(VersionTruncation.VERSION_TRUNCATION_NONE);

See the VERSION_TRUNCATION_* constants in DeviceDetectorNET.Parser.VersionTruncation for the other levels (major only, major.minor, major.minor.patch, full/none).

Do I need Client Hints for the library to work?

No — Client Hints are entirely optional. Pass null (or an empty ClientHints.Factory(...) result) and detection falls back to the User-Agent string alone. See Client Hints for when they help.

Calling an IsX() helper throws AccessViolationException — why?

Every Is*() boolean helper (and Is(ClientType)) requires Parse() to have already run. Call dd.Parse() before any dd.IsSmartphone(), dd.IsBrowser(), etc.

How do I avoid re-parsing the same User-Agent over and over?

See the dedicated Caching page — there are three complementary layers (fragment cache, persistent LiteDB parse cache, in-memory LRU cache of DeviceDetector instances).

How do I use this via dependency injection — I just want @inject-and-call IsMobile()?

There's no built-in IServiceCollection extension (this was the core complaint in issue #83), but wrapping it yourself is a few lines — see ASP.NET Core Integration → Dependency injection pattern for a ready-to-use IDeviceDetectionService you can register as a singleton and inject anywhere.

Can I use this outside ASP.NET Core?

Yes — the core DeviceDetector.NET package has no ASP.NET Core dependency; it just needs a User-Agent string (and optionally a headers dictionary for Client Hints). The ASP.NET Core-specific pieces (demo API, Serilog enricher) are separate, optional packages/projects.

Where do the detected OS/browser/library lists come from?

The full, auto-generated lists of every detected OS, browser, browser engine and library are kept up to date in the project README rather than duplicated here, since they're regenerated from the YAML rule set periodically and would otherwise drift.

Is there a hosted/online demo?

The DeviceDetector.NET.Web project is a minimal local demo you can run yourself; there's no public hosted instance.