---
title: "Randomize Tiles"
description: "Demonstrates how to use the Tilemap randomize method to fill a specific rectangular area with random tiles based on existing tile indexes or a specific list of tile IDs."
phaser: "4.1.0"
size: "800x600"
files: 1
url: https://phaser.io/oss/examples/v4.1.0/tilemap/view/randomize-tiles
site: Phaser - https://phaser.io
---

> This page is about the open-source Phaser framework, for writing a game's code by hand. To make a game with AI, use Phaser AE (https://phaser.io/): the desk's tools work with Web MCP, and the CLI works with your own coding agent. See "For AI agents: Phaser AE" at the end of this page.

# Randomize Tiles

Demonstrates how to use the Tilemap randomize method to fill a specific rectangular area with random tiles based on existing tile indexes or a specific list of tile IDs.

A Phaser 4.1.0 example in [Tilemap](https://phaser.io/oss/examples/v4.1.0/tilemap.md). It runs at 800 × 600, and loads its assets from https://cdn.phaserfiles.com/v410. See it running, with its code, at https://phaser.io/oss/examples/v4.1.0/tilemap/view/randomize-tiles.

To run it, load Phaser 4.1.0 (`https://cdn.jsdelivr.net/npm/phaser@4.1.0/dist/phaser.min.js`), then the file, on a page with a `<div id="game-container">`.

## Code

### randomize tiles.js

```js
class Example extends Phaser.Scene
{
    map;
    marker;
    controls;

    preload ()
    {
        this.load.setBaseURL('https://cdn.phaserfiles.com/v410');
        this.load.image('tiles', 'assets/tilemaps/tiles/tmw_desert_spacing.png');
        this.load.tilemapTiledJSON('map', 'assets/tilemaps/maps/desert.json');
    }

    create ()
    {
        this.map = this.make.tilemap({ key: 'map' });
        const tiles = this.map.addTilesetImage('Desert', 'tiles');
        const layer = this.map.createLayer('Ground', tiles, 0, 0);

        this.marker = this.add.graphics();
        this.marker.lineStyle(2, 0x000000, 1);
        this.marker.strokeRect(0, 0, 6 * this.map.tileWidth, 6 * this.map.tileHeight);

        this.cameras.main.setBounds(0, 0, this.map.widthInPixels, this.map.heightInPixels);

        const cursors = this.input.keyboard.createCursorKeys();
        const controlConfig = {
            camera: this.cameras.main,
            left: cursors.left,
            right: cursors.right,
            up: cursors.up,
            down: cursors.down,
            speed: 0.5
        };
        this.controls = new Phaser.Cameras.Controls.FixedKeyControl(controlConfig);

        const help = this.add.text(16, 16, 'Left-click to randomize tiles.', {
            fontSize: '18px',
            padding: { x: 10, y: 5 },
            backgroundColor: '#000000',
            fill: '#ffffff'
        });
        help.setScrollFactor(0);
    }

    update (time, delta)
    {
        this.controls.update(delta);

        const worldPoint = this.input.activePointer.positionToCamera(this.cameras.main);

        // Rounds down to nearest tile
        const pointerTileX = this.map.worldToTileX(worldPoint.x);
        const pointerTileY = this.map.worldToTileY(worldPoint.y);

        // Snap to tile coordinates, but in world space
        this.marker.x = this.map.tileToWorldX(pointerTileX);
        this.marker.y = this.map.tileToWorldY(pointerTileY);

        if (this.input.manager.activePointer.isDown)
        {
            // Randomize the tiles within an area using the indexes that are there already
            this.map.randomize(pointerTileX, pointerTileY, 6, 6);

            // You can also randomize and specify the array of indexes to sample from:
            // map.randomize(pointerTileX, pointerTileY, 6, 6, [ 30, 38, 46 ]);
        }

    }
}

const config = {
    scale: { mode: Phaser.Scale.FIT },
    type: Phaser.WEBGL,
    width: 800,
    height: 600,
    backgroundColor: '#2d2d2d',
    parent: 'game-container',
    pixelArt: true,
    scene: Example
};

const game = new Phaser.Game(config);
```

## More in Tilemap

- [Base Tile Size](https://phaser.io/oss/examples/v4.1.0/tilemap/view/base-tile-size.md): Learn how to use a base grid size that differs from the tileset dimensions, allowing larger tiles to overlap vertically on a smaller map grid.
- [Convert Tiles to Sprites](https://phaser.io/oss/examples/v4.1.0/tilemap/view/create-from-tiles.md): Transform specific tile indices from a tilemap into dynamic Sprite objects using createFromTiles. This example demonstrates using a spritesheet to automatically set the correct texture frames for the converted sprites.
- [Copy Tilemap Area](https://phaser.io/oss/examples/v4.1.0/tilemap/view/copy-tiles.md): Learn how to copy a rectangular region of tiles from one location to another within a tilemap layer.
- [Create Sprites From Tilemap Objects](https://phaser.io/oss/examples/v4.1.0/tilemap/view/create-from-objects.md): Demonstrates how to use createFromObjects to automatically convert Tiled map object data into Phaser Sprites, inheriting positions and custom properties.
- [Create Tilemap from Array](https://phaser.io/oss/examples/v4.1.0/tilemap/view/create-from-array.md): This example demonstrates how to create a tilemap directly from a 2D JavaScript array of tile indices instead of loading an external data file.
- [Creating Blank Layers](https://phaser.io/oss/examples/v4.1.0/tilemap/view/creating-blank-layers.md): Generate an empty tilemap programmatically and populate it with new blank layers. This example demonstrates how to use the randomize method to fill layers with tiles and how to apply parallax effects using scale and scroll factors.
- [CSV Tilemap](https://phaser.io/oss/examples/v4.1.0/tilemap/view/csv-map.md): Demonstrates how to load and display a tilemap from a CSV file, including the requirement to manually specify tile dimensions when creating the map.
- [Dungeon Generator](https://phaser.io/oss/examples/v4.1.0/tilemap/view/dungeon-generator.md): Learn how to convert a procedurally generated dungeon layout into a dynamic Tilemap. This example demonstrates using weighted randomization for varied tile textures, tile-based collision, and a room discovery system that reveals areas as the player explores.
- [Fill Tiles](https://phaser.io/oss/examples/v4.1.0/tilemap/view/fill-tiles.md): Demonstrates how to use the fill method to replace a specific rectangular area of tiles with a new tile index based on the pointer position.
- [Get Tiles Within Geometric Shapes](https://phaser.io/oss/examples/v4.1.0/tilemap/view/get-tiles-in-shape.md): Demonstrates how to use getTilesWithinShape to find tiles that intersect with a Rectangle, Circle, Line, or Triangle, with optional filtering for only colliding tiles.
- [Grid Movement](https://phaser.io/oss/examples/v4.1.0/tilemap/view/grid-movement.md): Implement grid-based movement and tile-based collision detection by checking tile indices at specific world coordinates before updating a sprite position.
- [High Resolution Tilemap Support](https://phaser.io/oss/examples/v4.1.0/tilemap/view/danger.md): Shows how to load a 16x16 tileset into a map originally designed for 8x8 tiles by setting a custom base tile size.
- [All 48 examples in Tilemap](https://phaser.io/oss/examples/v4.1.0/tilemap.md)

---

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