Comparison August 18, 2026

LINE Buttons Template: What to Use When Four Actions Aren’t Enough

A LINE Messaging API buttons template supports up to four objects in its actions array. If your card needs more than four visible choices, do not squeeze them into the copy or create ambiguous labels. Use quick replies for a short-lived menu, a carousel for item-based browsing, a Flex Message for a custom information hierarchy, or split the decision into two conversational steps.

Key takeaways

The official Messaging API reference sets the buttons template actions array to a maximum of four objects.
A separate optional action can make the image, title, or text area tappable, but it does not create a fifth visible button.
Quick replies support up to 13 buttons and suit immediate, temporary choices.
Carousel templates are better when choices belong to separate products, locations, or records.
Flex Messages provide a more customizable layout, but they require more design and validation work.

What the LINE buttons template four-action limit means

LINE describes template messages as predefined layouts for richer interactions. The buttons template has space for an image, title, text, and action buttons. Its actions array is required and accepts no more than four action objects. The template can also assign an optional action to the image, title, or text area.

That distinction matters. A tappable card area may provide a natural “view details” path, but it should not be treated as a hidden fifth menu choice. Users need to understand where a tap will take them, and the four visible actions still need clear, distinct labels.

This article covers the Messaging API buttons template, not the similarly named LINE MINI App custom action button. If you are implementing liff.shareTargetPicker() and LINE’s prescribed share card, use the separate LINE MINI App custom action button guide.

Buttons, quick replies, carousel, or Flex Message?

The right replacement depends on why you need more than four choices.

Option	Best for	Main constraint	Choose it when
Buttons template	One card with one to four primary actions	Maximum four objects in `actions`	Every action is important and fits one clear card
Quick replies	A temporary menu or next-step question	Buttons can disappear as the conversation continues	The user should choose immediately from up to 13 options
Carousel template	Repeating items such as products, branches, or appointments	Content must be organized into consistent columns	Each item needs its own image, text, and actions
Flex Message	Branded or information-dense layouts	More JSON, rendering, and device testing	The hierarchy cannot be expressed cleanly by a standard template
Two-step conversation	Long lists that can be grouped	Requires an extra user turn	You can ask for a category first, then show relevant choices

The official message types overview documents buttons, confirm, carousel, image carousel, and Flex Messages as distinct message types. They are alternatives with different interaction models, not merely larger versions of the same card.

Use quick replies for immediate choices

LINE allows up to 13 quick reply buttons on a message. They appear at the bottom of the chat and are designed for a response to the current prompt. This works well for options such as language, delivery window, issue type, or store location.

Do not use quick replies as persistent navigation. LINE documents conditions under which they disappear, including when a new message arrives in the room. If the user must return to the choices later, use a durable message layout or send the choices again at the appropriate state.

Use a carousel when each option is an item

A carousel is a better model when the choices are not equivalent commands but separate records. For example, four store branches should not consume all four actions on one card if each branch also needs “Directions,” “Hours,” and “Contact.” Put each branch in its own consistent column instead.

Keep the columns comparable. If one column represents a product and another represents an unrelated support command, the carousel becomes harder to scan and maintain.

Use Flex Message when layout is the problem

A Flex Message is useful when the constraint is visual hierarchy rather than the number of decisions. LINE’s Flex Message elements documentation includes button components with tappable actions and multiple styles.

Flex is not permission to place every possible action on one screen. Mobile readability, label clarity, accessibility, and rendering differences still matter. Use the Flex Message Simulator and validate the final object before release.

Use two steps when the list reflects business logic

Often the cleanest answer is not a larger message. Ask one high-level question first:

“What do you need help with?” — Orders, Returns, Product advice, Account.
Show only the actions relevant to the selected category.

This keeps each decision short and gives your backend an explicit routing state. It also makes analytics more meaningful because each tap represents one level of intent.

A practical design checklist

Before replacing a four-button template, run these checks:

Rank actions by user intent. Keep the most common and consequential actions visible.
Separate navigation from response input. Persistent destinations and immediate answers should not share one crowded menu.
Group long lists. If choices naturally form categories, use a two-step conversation.
Keep action labels distinct. “More,” “Other,” and “Details” on the same card create avoidable ambiguity.
Handle every action server-side. A polished card still fails if postback or message actions are not mapped to a valid state.
Test on supported mobile clients. Review truncation, image crops, tap targets, and the return path after each action.

If your decision concerns MINI App service messages versus Messaging API reply or push messages, first compare their triggers and eligibility in LINE Service Messages vs Messaging API. Choosing the correct message surface comes before choosing a layout.

Where UnifyPort fits—and where it does not

The choices above are official LINE Messaging API presentation features. UnifyPort does not recreate buttons templates, quick replies, carousel templates, or Flex Message layouts. Use the official LINE path when those native UI components are a requirement.

UnifyPort fits a different job: receiving LINE conversations through an unofficial interface and routing normalized inbound events into your backend. The current provider message support matrix shows which normalized outbound payload types are mapped for LINE, while the standard webhook event documentation defines the message.received envelope used across supported platforms.

That separation can simplify an architecture decision:

Need official interactive cards in a LINE Official Account flow? Use the Messaging API and select the correct official message type.
Need to receive and route ordinary LINE account messages into an existing support queue? Evaluate UnifyPort’s inbound path.
Need both? Treat them as separate surfaces with explicit ownership rather than assuming one message format can serve both identities.

For more context on the inbound path and its limitations, read how to receive LINE messages without registering an Official Account.

Limitations and trade-offs

A standard buttons template remains the simplest option when four actions are enough. Quick replies provide more choices but are temporary. Carousels improve item browsing but require consistent content. Flex Messages increase layout control and testing effort. A two-step flow adds one interaction but usually produces a clearer decision.

Also remember that official client behavior and object validation can change. Check the current LINE reference before shipping, especially if your implementation depends on exact object limits or rendering behavior.

FAQ

How many actions can a LINE Messaging API buttons template have?

The actions array accepts a maximum of four action objects. The optional action on the image, title, or text area is separate and does not add another visible button.

Can I add more than four LINE buttons with quick replies?

Yes. LINE documents up to 13 quick reply buttons on a message. Use them for an immediate response, not persistent navigation, because they can disappear as the chat continues.

Should I use a carousel or Flex Message for more actions?

Use a carousel when each choice is a repeated item with a consistent structure. Use a Flex Message when you need a custom visual hierarchy. If the list is logically grouped, a two-step conversation may be clearer than either.

Does UnifyPort send LINE buttons templates?

No. UnifyPort’s documented normalized LINE sending support does not include official buttons templates, carousel templates, quick replies, or Flex Messages. It is relevant when the main requirement is receiving and routing LINE messages through a normalized webhook.

Next step

Review the UnifyPort provider message support matrix before choosing an inbound or outbound architecture. For native buttons, quick replies, carousel, or Flex layouts, implement against LINE’s official Messaging API documentation.

Sources

Official sources checked on August 18, 2026: