IntelliJ IDEA requires Internet connection for a wide variety of tasks. For example:
- Checking for IntelliJ IDEA updates.
- Code inspections that can verify external resources.
- Communication with the version control servers, task servers.
- Anonymous usage statistics.
- Resolving Maven dependencies and updating plugins.
- Using IDEtalk plugin.
Besides that IntelliJ IDEA provides IPC for commands (for example, open files), and the built-in Web server.
Some of the communication requirements are configurable:
- Checking for updates can be turned off. To disable checking for updates, open the page Settings | Updates, and clear the check box Check for updates in channel.
- To turn off IDEtalk plugin, open the page Settings | Plugins, and make sure that the check box to the left of the plugin name is cleared.
- To use only those Maven resources that are available locally, open the page Settings| Maven, and select the check box Work offline
- To disable code inspection that highlights dead links, open the page Settings | Inspections, and clear the check box to the left of the HTML inspection Non-existent web resources.
- You can control the frequency of sending usage statistics, or even completely disable this function in the page Settings | Usage statistics.