Project Background: The Interface Isn't the Protocol
Project V provides the project background for a modular suite of proxy tools, and V2Ray is a widely used name in this ecosystem. In everyday usage, “V2Ray client” often means a graphical configuration manager, not one specific protocol. The client stores server settings, organizes subscription groups, presents options, and calls the core. The core parses configurations, applies routing, and establishes connections. Being able to import a configuration doesn't mean the underlying core supports every field in it.
This also explains why the same subscription can work across devices, while system traffic capture and app scope need to be configured separately. Server settings may come from the same source, but local listeners, system permissions, configuration storage, and background policies depend on the platform. Compare the workflows and features you actually need, not just how similar the interfaces look.
Core Families: Shared Origins, Independent Development
V2Fly continues the V2Ray community ecosystem, while Xray developed as a fork based on related code. They share some configuration concepts but have developed distinct features and implementations. Some legacy settings may map across, but newer features, default values, transport support, and resource formats can differ. Check the specific core for features such as REALITY; a shared ecosystem doesn't guarantee full compatibility.
On desktop, check which core v2rayN is currently using before reviewing the relevant error. On Android, choose between v2rayNG and v2flyNG based on your needs. Switching cores isn't a general-purpose speed boost. If the bottleneck is remote server load or network quality, changing the client name is unlikely to help. If a field is incompatible, the specific error in the logs is more useful than a speed test.
Open-Source Licenses: Check the Client and Its Dependencies
All three clients are released as open-source software. v2rayN and v2rayNG use GPL-family licenses, as does v2flyNG; the V2Fly and Xray cores use MPL 2.0. These licenses apply to different components. A client's open-source status doesn't replace the licensing terms for its dependencies. Before modifying, redistributing, or integrating software, read the specific licenses for the projects and bundled dependencies you use.
Open source makes it possible to inspect implementations, investigate issues, and contribute improvements. Whether software suits your device still depends on system compatibility, configuration needs, and real-world results. This guide bases its recommendations on platform, core, and setting responsibilities—not download counts, ratings, or performance rankings without adequate testing.
Updates: Maintain the App, Core, and Subscription Separately
An app update can change the interface or how configurations are generated; a core update can change connection support and implementation; a subscription update changes the source of server configurations; and a routing resource update affects some rule-matching data. These are separate operations. An older core may not support new protocol parameters in a subscription. Updating the client won't automatically fix an outdated subscription or an unavailable server.
Keep a recoverable copy of your configuration and custom rules before updating. Afterward, verify startup, subscription updates, traffic capture, and real connections in order. Adjust components only when you encounter a specific compatibility issue or need a new feature to keep troubleshooting focused. For terminology, see the glossary. For import, permission, or connection issues, browse the FAQ categories by symptom.