From Project V to two core families
Project V is a useful starting point for understanding the V2Ray ecosystem. In everyday searches, “V2Ray” may refer to a proxy core or more broadly to the clients and configurations built around it. V2Fly continues community development of V2Ray, while Xray grew from related code into a separate core family. They share some technical background, but their features and configuration support are not identical. When reading a guide, first check which core it covers; fields with the same name or similar menu options do not guarantee compatibility.
The core handles protocols, routing decisions, and network connections. The graphical client provides subscription management, server lists, logs, and controls. The service provider supplies remote addresses and connection parameters. Each layer has a different role. A successful subscription update only means the client retrieved and parsed the configuration; selecting a server does not mean the system proxy is enabled. Testing each layer separately is more effective than repeatedly changing every setting.
Choose a core for your configuration needs
VMess, VLESS, and Trojan are connection protocols; features such as REALITY and XTLS Vision also depend on specific implementations and configuration requirements. A server name alone does not establish compatibility, and a successful import does not guarantee a working connection. Check the server-side requirements against the available client cores and their support. Before migrating, keep the original configuration and test one entry. Confirm the protocol, transport, security settings, and DNS behavior before moving the full subscription group.
v2rayN is a desktop client that organizes configuration in a graphical interface and uses the corresponding core. v2rayNG is for Android and uses the Xray core; v2flyNG offers an Android option based on the V2Fly core. All three are open-source projects, but their features are not interchangeable. If you use the same subscription across devices, check which core each device runs and which configuration fields it supports rather than comparing client names alone.
Separate open-source licenses from service terms
All three clients are released under the GPL-3.0 open-source license. The license sets the terms for using, modifying, and redistributing the code; it is not the terms of service for a remote proxy service and does not determine which provider to use. A free client and a paid subscription are separate things. Review the software license, service plan, and applicable network conditions independently. The client download page is not a place to obtain server accounts.
Open-source software does not, by itself, define the privacy boundaries of your device. Subscription URLs may contain identifiers, configurations may store server addresses and credentials, and logs may record destinations and error details. Share only the necessary excerpts when troubleshooting, and hide subscription URLs and credential fields in screenshots. If you receive an unfamiliar configuration, verify its source before importing it; don’t load a complete configuration from an unknown source just to fix a connection.
Handle software and subscription updates separately
Updating the client, updating the core, and updating a subscription are separate operations. A client update changes the interface and configuration management; a core update may change protocol support or network behavior; a subscription update fetches the server configuration published by your provider. Change one layer at a time and keep settings you can roll back to. This helps identify whether an issue comes from a software change, a subscription change, or the current network. The download page lists available installers; the home page explains how to choose and configure them.
Before upgrading, note your subscription groups, routing choices, system proxy setting, and TUN state. After upgrading, test the basic connection before restoring custom rules. If an old configuration behaves differently in the new environment, check the logs and the relevant feature guide instead of immediately replacing all your settings. The menu locations shown on this page illustrate the workflow; the actual interface may vary by client version. If you can’t find an option, check the relevant platform section in the installation guide.