---
description: What field are, which kinds are provided by default, and how to customize them.
title: Fields
image: images/blockly_banner.png
---

# Fields

Fields are used to define most UI elements on a block. Examples of fields
include string labels, images, inputs for literal data such as strings and
numbers, and rich editors like date pickers and angle pickers. The simplest
example of a field is the `math_number` block, which uses a `field_number` to
let the user type a number.

![A block with a number field.](/images/math-number.png)

:::note
If you need to show meta-information about a block, you probably want an
icon instead. Read more about [Fields vs Icons][fields-vs-icons].
:::

Blockly provides several fields by default to handle a variety of user input.
These can be customized through field-specific configuration or with validators,
which tell a field how to handle specific content in a standard editor.

→ More info on [Built-in fields](/guides/create-custom-blocks/fields/built-in-fields/overview).

→ More info on [Validators](/guides/create-custom-blocks/fields/validators).

If you need a fully custom field it takes a bit more work and you'll want to
read most of the fields documentation. Start by learning about the parts
that make up a field or the overview of creating custom fields.

→ More info on the [anatomy of a field](/guides/create-custom-blocks/fields/anatomy-of-a-field).

→ More info on [creating custom fields](/guides/create-custom-blocks/fields/customizing-fields/overview).

[fields-vs-icons]: /guides/create-custom-blocks/fields/fields-vs-icons
