# FAQ entries tagged #Help

There is no technical support desk for individual developers. See Documentation for information on the development process and specifications of the LINE APIs. For questions and advice regarding development, see the voluntary Q&A (opens new window) in the LINE Developers Community.

If you are a corporate customer and need technical support for LINE APIs, contact our Technology Partners (opens new window) for technical support. Any inquiry regarding the LINE APIs should be through our Technology partners.

To report a problem encountered on the LINE platform or make a request for improvement, contact us using the help center's Inquiry form (opens new window). Note that we may not be able to respond to all inquiries.

If you need technical support, see How do I contact technical support for inquiring about LINE APIs? in the FAQ.

Auto login can be used in these situations. You don't need to perform any special configurations when implementing LINE Login into your web app to use Auto login.

  • iOS

    • Auto login can be used when accessing a web app where LINE Login v2.0 or v2.1 is implemented using LINE's in-app browser or the Safari browser.
  • Android

    • Auto login can be used when accessing a web app where LINE Login v2.0 or v2.1 is implemented using LINE's in-app browser or external browsers such as Chrome.

Auto login isn't supported for devices other than iOS and Android devices, devices where LINE isn't installed, and in browsers other than the Safari browser for iOS.

Also, we use iOS's Universal links (opens new window) and Android's Common intents (opens new window) features to perform auto login on external browsers. Check the official documentation for each OS for information on concepts such as how the dialog is displayed when using these features, the OS requirements for using these features, and how to disable these features.

For more information, see Auto login in the LINE Login documentation.

About automatic login from the Yahoo! JAPAN app

Auto login is enabled when accessing a web app that incorporates LINE Login with PKCE implementation from the Yahoo! Japan app. For more information on PKCE support for LINE Login, see PKCE support for LINE Login in the LINE Login documentation.

About the user ID issued by a certain provider, in the case that the corresponding LINE account is deleted, the same user ID won't be reused for other LINE accounts within the provider.

For more information on user IDs, see What are the user ID, group ID, room ID, and one-on-one chat ID values?

User IDs are issued by each channel provider. Once a user ID (userId) is issued for a specific provider, it won't change unless the user deletes their LINE account.

The user ID won't change even if the user transfers their LINE account to another device.

If a user deletes their LINE account and then re-creates a LINE account with the same phone number, the user ID will change.

For more information on user IDs, see What are the user ID, group ID, room ID, and one-on-one chat ID values?

We don't disclose IP addresses.

We prevent unauthorized requests through SSL communication and Verifying signatures included in the webhook.

The user ID used by the LINE Platform identifies a user and has the following characteristics:

  • The value is generated by the LINE Platform, not by a user. This is different from the LINE ID on LINE used to search for friends.

  • Different user IDs are generated based on the provider of the channel. As long as channels have the same provider, regardless of whether the channel is for LINE Login or Messaging API, the same user ID is used for the users of the channels.

  • The user ID value is a string that matches the regular expression, U[0-9a-f]{32}.

The group ID and room ID used for group chats are values generated by the LINE Platform to identify groups and rooms.

The group ID is a string that matches the regular expression, C[0-9a-f]{32}, and the room ID is a string that matches the regular expression, R[0-9a-f]{32}.

In a LINE Front-end Framework (LIFF) app, the one-on-one chat ID (utou ID) is used to identify a one-on-one chat in addition to the three types of IDs mentioned above.

The one-on-one chat ID value is a string that matches the regular expression, UU[0-9a-f]{130}.

You can check the current status of a LINE API outage using these methods:

The iPad that created the LINE account or the iPad that took over the LINE account can display rich menus.

Other iPads can't display rich menus.

You can check the LINE settings screen to see if your iPad can display rich menus.

  • If Delete Account appears in Settings > Accounts, the iPad can display rich menus.

  • If Logout appears in Settings > Accounts, the iPad can't display rich menus.