# FAQ entries tagged #Messaging API

Q
I made a rich menu with Bot Designer but it isn't working.

In Chats mode, click on a rich menu from the Rich Menu pane located on the bottom right to activate it.

Q
I made a template message in Bot Designer but the link doesn't work.

Check if you have included "http://" or "https://" in the URL. The link must be in the same URL format as used on browsers.

Message actions will work normally when added to the chat in Chats mode.

The actual LINE chatbot only accepts URLs starting with "https://" to ensure security. LINE Bot Designer doesn't have this limitation to encourage the creation of any chatbot prototype.

Q
Can I change the company name on the bottom of the profile page?

The company name displayed on the bottom of the profile page is your Provider name. You can change your Provider name by following these steps:

  • For Certified providers (Certified providers have a certified provider badge before their company name)

    You need to submit an application to LINE, so contact your sales representative.

  • For non-Certified providers

    From the LINE Developers Console, select provider, click Settings, and from the Provider settings, and click the Edit button under Provider name.

    Provider name edit

*It will take some time before the change of provider name is reflected on your profile page.

Q
How many channels can I create?

See The number of channels that can be created in the LINE Developers Console documentation.

Q
Where can I find my Channel ID?

You can find your Channel ID on the LINE Official Account Manager (opens new window) or the LINE Developers Console.

  • LINE Official Account Manager (requires Admin role):

    Select account from accounts list and click Settings in the top-right corner of the page. Click Messaging API from the side menu, and you will see your Channel ID next to Channel Info.

    OAM settings

  • LINE Developers Console:

    From the LINE Developers Console, select provider, and then select channel. You can find your Channel ID under Basic settings.

    Console settings

Q
Where can I find my Provider ID?

You can find your Provider ID on the LINE Developers Console.

  • If you have Provider Admin role:

    From the LINE Developers Console, select provider and then click Settings. You can find your Provider ID under Provider settings.

    Provider ID Admin

  • If you don't have Provider Admin role:

    From the LINE Developers Console, select provider. From the page displayed, you will see your Provider ID in the segment after /provider/ in the URL.

    Provider ID URL

Q
How do I report an issue about the LINE Platform?

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.

Q
How can I get a user's phone number?

You can use LINE Profile+ to get a user's phone number. For more information, see LINE Profile+ scopes in the Options for corporate customers documentation.

LINE Profile+ is only available to corporate users who have completed certain applications. If you wish you use LINE Profile+, contact your sales representative or contact our Sales partners (opens new window).

Q
Is it possible for the user IDs of users who have deleted their LINE accounts to be used again?

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, and room ID values?

Q
What are the user ID, group ID, and room ID values?

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 used for group chats and the room ID used for multi-person chats are values generated by the LINE Platform to identify group chats and multi-person chats.

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}.

Q
Once a user ID is issued, can it be changed at any time?

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, and room ID values?

Q
Where can I check the status of LINE API outage?

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

Q
How are the URL previews in chats and on LINE VOOM generated?

LINE uses Open Graph Protocol tags from websites to generate URL previews.

The three OGP tags used by LINE:

# Open Graph Protocol tag Example
1 og:title <meta property="og:title" content="LINE : Free Calls & Messages">
2 og:description <meta property="og:description" content="LINE is a new communication app">
3 og:image <meta property="og:image" content="http://static.naver.jp/line_lp/img/ogp.png">

Example of URL preview:

URL preview in chat

OGP configuration

Even if you don't configure OGP tags, any text or image within the URL will be automatically retrieved to generate a URL preview.

For example, for the Title, if there is no available information in og:title, the text within the title tag will be displayed. Likewise, for the Summary, if there is no available information in og:description, the text within either the description tag or the body will be displayed (If there is no retrievable information, nothing will be displayed in the preview).

LINE uses only the three OGP tags listed above. URL previews will not include information contained in any other OGP tags.

Tip

A cache-deletion tool (opens new window) for deleting the LINE server side cache of your URL preview is now available.

Q
Can I block a user who has added my LINE Official Account as a friend?

You can't block a user who has added your LINE Official Account as a friend.

Q
Can I determine if a user is a friend of my LINE Official Account?

You can determine with a follow event and an unfollow event of webhook events. There is no endpoint to determine if a user is a friend of your LINE Official Account.

Q
Can I get the list of group chats and multi-person chats that my LINE Official Account is participating in?

Currently, you can't get the list of group chats and multi-person chats that your LINE Official Account is participating in.

Q
Can I internationalize or multilingualize messages and rich menus?

Currently, there is no function to switch the language of messages or rich menus based on the user's language.

Use the Get profile endpoint to get the user's language, and then send messages or set up a per-user rich menu based on the user's language.

Q
Can I make the background of rich menus transparent?

No, you can't make the background of rich menus transparent.

Q
Can I see the paths taken by users to add my LINE Official Account as a friend on a per-user basis?

You can't use the Messaging API to see how a specific user added your LINE Official Account as a friend.

You can see the friend adding paths statistics, without identifying individual users, in the LINE Official Account Manager (opens new window). For more information, see Insight analytics - Friends (opens new window) (only available in Japanese) in LINE for Business.

Q
If a user shares my LINE Official Account with a friend, can I see the result of the friend referral (whether my LINE Official Account was added as a friend or not, and how many people added the LINE Official Account)?

No, you can't.

When the person to whom the LINE Official Account was referred adds them as a friend or unblocks them, a webhook follow event is sent from the LINE Platform to the bot server. However, you can't use the Messaging API to confirm how the user added the LINE Official Account as a friend (i.e., whether the user added the LINE Official Account as a friend through someone's referral).

It is also not possible to confirm the number of people who have friended the LINE Official Account as a result of friend referrals.

Q
Can I see who has read a message I've sent from my LINE Official Account?

You can't use the Messaging API to verify that a message you sent was read. You can get statistics about your sent messages on the following endpoints:

Q
Can I send PDF files with the Messaging API?

You can't send PDF files with the Messaging API.

Q
Can I send purchased or company-owned stickers using the Messaging API?

Using the Messaging API, you can send only the stickers listed in the Stickers.

You can send other stickers using the following methods:

  • You can send stickers that you own with your LINE account. To send your own stickers, go to "Chats" in the LINE Official Account Manager (opens new window) or the LINE Official Account Manager App. For more information, see Chats (opens new window) (only available in Japanese) in LINE for Business.
  • Only corporate users who have submitted the required applications can send stickers owned by the company such as sponsored stickers or creators' stickers. To send these stickers from your LINE Official Account, contact your sales representative or contact our Sales partners (opens new window).
Q
If my LINE Official Account is alreadly linked to a Messaging API channel, can I un-link my LINE Official Account from the Messaging API channel?

Once you've linked your LINE Official Account to a Messaging API channel, you can't un-link your LINE Official Account from the Messaging API channel.

If you want to continue using your LINE Official Account linked to the Messaging API channel, but want to stop using the Messaging API, see Stop using the Messaging API in the Messaging API documentation.

Q
Can I unsend or delete a message sent from my LINE Official Account?

No, you can't unsend or delete your message sent from your LINE Official Account when using the Messaging API.

You also can't cancel the process of sending a message after you have requested to send a message.

Q
Do messages sent using the Messaging API reach users immediately?

Messages sent using the Messaging API may take some time to reach the user.

Messaging requests to each endpoint of the Messaging API are processed asynchronously. For this reason, if a LINE Official Account has many friends, or if there are a large number of requests from other LINE Official Accounts at the same time, it may take some time for the message sending process to be completed.

Q
Does it cost money to use the Messaging API?

For more information about Messaging API pricing, see Messaging API pricing.

Q
How can I get the name and profile image of a group chat?

With the Get group chat summary API, you can get the name, and URL of the icon of the group chat that the LINE Official Account is participating in.

Q
Can I delete the bot for my LINE Official Account?

To delete the bot, you need to delete your LINE Official Account.

Q
How can I find out the file format of the retrieved content?

When you get content, the file format of the binary data returned in the response is indicated in the Content-Type (opens new window) header of the response.

By checking the value of the Content-Type header, you can find out the file format of the content. Examples of file format indicated by the Content-Type header are as follows:

Content sent by users Content-Type header example
Image image/jpeg
Video video/mp4
Audio audio/x-m4a
File text/plain
Q
How can I use the Messaging API with my existing LINE Official Account?

To use the Messaging API with your existing LINE Official Account, enable the Messaging API on the LINE Official Account Manager (opens new window).

For more information, see Use the Messaging API with your existing LINE Official Account in the Messaging API documentation.

Q
If I send a message to a user who doesn't receive the message, is it still counted as one message?

If you specify a user who doesn't actually receive the message, such as a user ID that blocked the LINE Official Account or a user ID that doesn't exist, the message won't be counted even if you call the API for sending the message.

Q
Do I get an error when I send a message with a user ID that blocks the LINE Official Account?

If you send a message specifying a user who has blocked the LINE Official Account or a user who deleted their account, no error will occur and status code 200 will be returned as a response.

In this case, no message will be sent to the user.

Q
I want to restrict access to the bot server from non-LINE Platform. Is the IP address of the LINE Platform public?

No, the IP address of the LINE Platform from which the webhook request is sent isn't disclosed. For better security, use signature validation instead of access control by IP address.

Q
If I send a push message with multiple message objects (for example, 4) in a single request to a group chat or multi-person chat with multiple people (for example, 5 people), how many messages will be counted?

The number of messages is counted by the number of people to whom the message was sent. In this example, if there are five people in the group chat or multi-person chat where you sent the message, the number of messages counted is five. The number of message objects specified in a single request doesn't affect the number of messages sent.

For message count when you send a message to a user who doesn't receive the message, see If I send a message to a user who doesn't receive the message, is it still counted as one message?.

For more information on pricing, see Messaging API pricing.

Q
If I set multiple message objects in the request body when sending a message, will the messages be delivered in the order they are set from the top?

Yes.

If multiple message objects are set in the request body when sending a message, the messages will be delivered in the order they are set from the top.

Q
How many full-width characters, emojis, line breaks, and so on, are counted in the text character count?

Characters in a text are counted in UTF-16 code units (16-bit). Characters expressed in multiple code units, such as some kanji characters and Unicode emojis, are counted as multiple characters instead of one character.

However, some properties are counted in grapheme cluster (opens new window) units rather than UTF-16 code units. For more information, see Character counting in a text in the Messaging API documentation.

Also, unlike Unicode emojis, LINE emojis provided by LINE are internally converted to the alternative text (e.g., (love)), so they're counted by the number of characters in the alternative text.

Examples of counting the number of characters in UTF-16 code units are as follows:

Character UTF-16 encoded value Number of code units Number of characters
a 0061 1 1 character
3042 1 1 character
\n 000A 1 1 character
908A 1 1 character
𠀋 D840 DC0B 2 2 characters
👋 D83D DC4B 2 2 characters
👋🏻 D83D DC4B D83C DFFB 4 4 characters
Q
Is the message ID in the message webhook event object unique per message type or per channel?

Message IDs are assigned a value that is unique throughout the Messaging API environment.

It doesn't mean that it's unique for each channel or message type, such as an image.

Q
If I send multiple messages to the same user with the Messaging API, in what order will the messages be displayed?

The order in which messages are displayed depends on how the messages are sent.

If endpoints used for sending messages are executed multiple times, the order in which the endpoints are executed and the order in which the messages will be displayed won't be necessarily the same.

If an endpoint for sending messages is executed once and multiple messages are specified in the request body, the messages will be displayed in the order specified in the request body.

Q
Where can I find my user ID?

You can find your user ID in the Your user ID of the Basic settings tab of the channel in the LINE Developers Console. For more information, see Developer gets their own user ID in the Messaging API documentation.

Q
Why can't I receive webhook events?

Your account may not have been set up to allow webhooks. To allow webhooks, enable Use webhook on the Messaging API tab of your channel settings on the LINE Developers Console.

Q
Why can't I save on Keep or forward videos that are sent from a LINE Official Account?

End users can't save on Keep or forward videos sent from a LINE Official Account.

Q
Why does my LINE Official Account automatically leave a group chat or multi-person chat after I've invited it?

It's possible that Allow bot to join group chats setting is disabled on your LINE Official Account, or that another LINE Official Account has already joined the group chat or multi-person chat you invited.

For more information, see Add LINE Official Account in group & multi-person chats in the Messaging API documentation.

Q
Why does my LINE Official Account automatically send replies?

Depending response settings on the LINE Official Account Manager, the LINE Official Account will automatically send replies.

Click Edit in Auto-reply messages on the Messaging API tab of your channel settings on the LINE Developers Console to access LINE Official Account Manager and check Response setting.

LINE Official Account will automatically send replies in these cases:

  • If Greeting message is set to Enabled, it will automatically send replies when user adds your LINE Official Account as a friend.
  • If Auto-response is set to Enabled, it will automatically send replies according to the preset conditions.
  • If Chat is set to On, depending on the Chat response method setting, it may automatically send replies.
Q
Why won't my iPad display rich menus?

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.