<input type="range">

"range" 型の <input> 要素は、ユーザーに一定の値より小さくなく、別な一定の値より大きくない数値を指定させるために使用します。しかし、厳密な値は重要であるとはみなされません。これは通常、 "number" 入力型のようなテキスト入力ボックスではなく、スライダーやダイアルコントロールを用いて表現されます。この種のウィジェットは厳密なものではないので、コントロールの値が厳密なものではない限り、通常は使用するべきではありません。

この対話型サンプルのソースファイルは GitHub リポジトリに格納されています。対話型サンプルプロジェクトに協力したい場合は、 https://github.com/mdn/interactive-examples をクローンしてプルリクエストを送信してください。

ユーザーのブラウザーが "range" 型に対応していない場合は、 "text" 入力にフォールバックされ、その型として扱われます。

値

The value attribute contains a DOMString which contains a string representation of the selected number. The value is never an empty string (""). The default value is halfway between the specified minimum and maximum—unless the maximum is actually less than the minimum, in which case the default is set to the value of the min attribute. The algorithm for determining the default value is:

defaultValue = (rangeElem.max < rangeElem.min) ? rangeElem.min
               : rangeElem.min + (rangeElem.max - rangeElem.min)/2;

If an attempt is made to set the value lower than the minimum, it is set to the minimum. Similarly, an attempt to set the value higher than the maximum results in it being set to the maximum.

範囲入力の使用

While the "number" type lets users enter a number with optional constraints forcing their value to be between a minimum and a maximum value, it does require that they enter a specific value. The "range" input type lets you ask the user for a value in cases where the user may not even care—or know—what the specific numeric value selected is.

A few examples of situations in which range inputs are commonly used:

• Audio controls such as volume and balance, or filter controls.
• Color configuration controls such as color channels, transparency, brightness, etc.
• Game configuration controls such as difficulty, visibility distance, world size, and so forth.
• Password length for a password manager's generated passwords.

As a rule, if the user is more likely to be interested in the percentage of the distance between minimum and maximum values than the actual number itself, a range input is a great candidate. For example, in the case of a home stereo volume control, users typically think "set volume at halfway to maximum" instead of "set volume to 0.5".

最小値と最大値の指定

By default, the minimum is 0 and the maximum is 100. If that's not what you want, you can easily specify different bounds by changing the values of the min and/or max attributes. These can be any floating-point value.

For example, to ask the user for a value between -10 and 10, you can use:

<input type="range" min="-10" max="10">

値の精度の設定

By default, the granularity, is 1, meaning that the value is always an integer. You can change the step attribute to control the granularity. For example, If you need a value between 5 and 10, accurate to two decimal places, you should set the value of step to 0.01:

<input type="range" min="5" max="10" step="0.01">

If you want to accept any value regardless of how many decimal places it extends to, you can specify a value of "any" for the step attribute:

<input type="range" min="0" max="3.14" step="any">

ハッシュマークとラベルの追加

The HTML specification gives browsers some flexibility on how to present the range control. Nowhere is this flexibility more apparent than in the area of hash marks and, to a lesser degree, labels. The specification describes how to add custom points to the range control using the list attribute and a <datalist> element, but does not have any requirements or even recommendations for standardized hash or tick marks along the length of the control.

範囲コントロールのモックアップ

Since browsers have this flexibility, and to date none support all of the features HTML defines for range controls, here are some mockups to show you what you might get on macOS in a browser which supports them.

簡素な範囲コントロール

This is what you get if you don't specify a list attribute, or if the browser doesn't support it.

HTML	Screenshot
<input type="range">

ハッシュマーク付きの範囲コントロール

This range control is using a list attribute specifying the ID of a <datalist> which defines a series of hash marks on the control. There are eleven of them, so that there's one at 0% as well as at each 10% mark. Each point is represented using an <option> element with its value set to the range's value at which a mark should be drawn.

HTML	Screenshot
<input type="range" list="tickmarks"> <datalist id="tickmarks"> <option value="0"> <option value="10"> <option value="20"> <option value="30"> <option value="40"> <option value="50"> <option value="60"> <option value="70"> <option value="80"> <option value="90"> <option value="100"> </datalist>

ハッシュマークとラベル付きの範囲コントロール

You can add labels to your range control by adding the label attribute to the <option> elements corresponding to the tick marks you wish to have labels for.

HTML	Screenshot
<input type="range" list="tickmarks"> <datalist id="tickmarks"> <option value="0" label="0%"> <option value="10"> <option value="20"> <option value="30"> <option value="40"> <option value="50" label="50%"> <option value="60"> <option value="70"> <option value="80"> <option value="90"> <option value="100" label="100%"> </datalist>

方向の変更

By default, if a browser renders a range input as a slider, it will render it so that the knob slides left and right. You can, however, easily change this to slide up and down instead using CSS.

Note: This is not actually implemented yet by any of the major browsers. See Firefox バグ 981916, Chrome Chromium bug 341071.

Consider this range control:

<input type="range" id="volume" min="0" max="11" value="7" step="1">

Screenshot	Live sample

This control is horizontal (at least on most if not all major browers; others might vary). Making it vertical is as simple as adding CSS to change the dimensions of the control so that it's taller than it is wide, like this:

CSS

#volume {
  height: 150px;
  width: 50px;
}

HTML

<input type="range" id="volume" min="0" max="11" value="7" step="1">

結果

Screenshot	Live sample

Currently, no major browsers support creating vertical range inputs using CSS this way, even though it's the way the specification recommends they do it.

The HTML specification recommends that browsers automatically switch to drawing range controls vertically if the specified width is less than the height. Unfortunately, no major browsers currently support vertical range controls directly. You can, however, create a vertical range control by drawing a horizontal range control on its side. The easiest way is to use CSS: by applying a transform to rotate the element, you can make it vertical. Let's take a look.

HTML

The HTML needs to be updated to wrap the <input> in a <div> to let us correct the layout after the transform is performed (since transforms don't automatically affect the layout of the page):

<div class="slider-wrapper">
  <input type="range" min="0" max="11" value="7" step="1">
</div>

CSS

Now we need some CSS. First is the CSS for the wrapper itself; this specifies the display mode and size we want so that the page lays out correctly; in essence, it's reserving an area of the page for the slider so that the rotated slider fits into the reserved space without making a mess of things.

.slider-wrapper {
  display: inline-block;
  width: 20px;
  height: 150px;
  padding: 0;
}

Then comes the style information for the <input> element within the reserved space:

.slider-wrapper input {
  width: 150px;
  height: 20px;
  margin: 0;
  transform-origin: 75px 75px;
  transform: rotate(-90deg);
}

The size of the control is set to be 150 pixels long by 20 pixels tall. The margins are set to 0 and the transform-origin is shifted to the middle of the space the slider rotates through; since the slider is configured to be 150 pixels wide, it rotates through a box which is 150 pixels on each side. Offsetting the origin by 75px on each axis means we will rotate around the center of that space. Finally, we rotate counter-clockwise by 90°. The result: a range input which is rotated so the maximum value is at the top and the minimum value is at the bottom.

結果

Screenshot	Live sample

検証

There is no pattern validation available; however, the following forms of automatic validation are performed:

• If the value is set to something which can't be converted into a valid floating-point number, validation fails because the input is suffering from a bad input.
• The value won't be less than min. The default is 0.
• The value won't be greater than max. The default is 100.
• The value will be a multiple of step. The default is 1.

例

In addition to the assorted examples above, you'll find range inputs demonstrated in these articles:

• Controlling multiple parameters with ConstantSourceNode

仕様書

ブラウザーの対応

このページの互換性一覧表は構造化データから生成されています。データに協力していただけるのであれば、 https://github.com/mdn/browser-compat-data をチェックアウトしてプルリクエストを送信してください。

関連情報

• HTML フォーム
• <input> およびそれに基づく HTMLInputElement インターフェイス
• <input type="number">