---
title: "Transition | Gl style specification"
description: "Control timing for smooth transitions between map style property values."
---

# Transition

A `transition` property controls timing for the interpolation between a transitionable style property’s previous value and new value. A style’s [root `transition`](../root/#transition) property provides global transition defaults for that style.

```json
"transition": {
  "duration": 300,
  "delay": 0
}
```

Any transitionable layer property, marked by , may also have its own \*-transition property that defines specific transition timing for that layer property, overriding the global transition values.

```json
"fill-opacity-transition": {
  "duration": 300,
  "delay": 0
}
```

## delay

Optional [number](../types/#number) greater than or equal to `0`. Units in milliseconds. Defaults to `0`.

Length of time before a transition begins.

## duration

Optional [number](../types/#number) greater than or equal to `0`. Units in milliseconds. Defaults to `300`.

Time allotted for transitions to complete.