Elements overview

What Block Kit elements are, where each one can live, and how they report interactions.

Elements are the interactive (and image) pieces you place inside a block: a button, a select menu, a date picker, a checkbox group. A block lays elements out; an element renders the control and, when the person interacts with it, reports what happened.

Your AppAPP12:00 PM

Deploy to production?

onActionInteract with the preview.

action_id

Every interactive element carries an action_id, a string you choose that identifies it within its block. When the element fires, Slack sends it back to your app in action_id so you know which control the person used. Combined with the block’s block_id, it’s also the path into state.values for elements that hold a value (see each element’s “Reading the value” section).

Where elements live

Slack restricts which elements can appear in which context:

actions block: up to 25 elements laid out in a row (some, like checkboxes and radio buttons, always take the full row).
Section accessory: one element to the right of (or, for checkboxes/radio buttons, stacked below) a section’s text.
input block: one element per block, used in modals and Home tabs to collect a value.
context_actions block: a trailing row of small icon-style actions, typically under an AI-generated message (feedback thumbs, copy, retry, overflow).

Element × block support

Element	`actions`	Section accessory	`input`	`context_actions`
Button	Yes	Yes	No	No
Overflow menu	Yes	Yes	No	No
Select menus	Yes	Yes	Yes	No
Checkboxes	Yes (full width)	Yes (stacked)	Yes	No
Radio buttons	Yes (full width)	Yes (stacked)	Yes	No
Date picker	Yes	Yes	Yes	No
Time picker	Yes	Yes	Yes	No
Date and time picker	Yes (full width)	No	Yes	No
Text inputs	No	No	Yes	No
Rich text input	No	No	Yes	No
File input	No	No	Yes (modals only)	No
Icon button	Yes	No	No	Yes
Feedback buttons	No	No	No	Yes
Image element	No	Yes	No	Yes
Workflow button	Yes	No	No	No

Button

The most common interactive element: default, primary, danger and link styles.

Select menus

Static, external, users, conversations and channels selects, single or multi.

Text inputs

Plain text, email, URL and number inputs for modals and Home tabs.

Confirmation dialogs

Add a confirm step to any element with the confirm object.