---
title: Math.tanh()
short-title: tanh()
slug: Web/JavaScript/Reference/Global_Objects/Math/tanh
page-type: javascript-static-method
browser-compat: javascript.builtins.Math.tanh
sidebar: jsref
---

The **`Math.tanh()`** static method returns the hyperbolic tangent of a number. That is,

<!-- prettier-ignore-start -->
<math display="block">
  <semantics><mrow><mrow><mo lspace="0em" rspace="0.16666666666666666em">𝙼𝚊𝚝𝚑.𝚝𝚊𝚗𝚑</mo><mo stretchy="false">(</mo><mi>𝚡</mi><mo stretchy="false">)</mo></mrow><mo>=</mo><mo lspace="0em" rspace="0em">tanh</mo><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>=</mo><mfrac><mrow><mo lspace="0em" rspace="0em">sinh</mo><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mrow><mo lspace="0em" rspace="0em">cosh</mo><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow></mfrac><mo>=</mo><mfrac><mrow><msup><mi mathvariant="normal">e</mi><mi>x</mi></msup><mo>−</mo><msup><mi mathvariant="normal">e</mi><mrow><mo>−</mo><mi>x</mi></mrow></msup></mrow><mrow><msup><mi mathvariant="normal">e</mi><mi>x</mi></msup><mo>+</mo><msup><mi mathvariant="normal">e</mi><mrow><mo>−</mo><mi>x</mi></mrow></msup></mrow></mfrac><mo>=</mo><mfrac><mrow><msup><mi mathvariant="normal">e</mi><mrow><mn>2</mn><mi>x</mi></mrow></msup><mo>−</mo><mn>1</mn></mrow><mrow><msup><mi mathvariant="normal">e</mi><mrow><mn>2</mn><mi>x</mi></mrow></msup><mo>+</mo><mn>1</mn></mrow></mfrac></mrow><annotation encoding="TeX">\mathtt{\operatorname{Math.tanh}(x)} = \tanh(x) = \frac{\sinh(x)}{\cosh(x)} = \frac{\mathrm{e}^x - \mathrm{e}^{-x}}{\mathrm{e}^x + \mathrm{e}^{-x}} = \frac{\mathrm{e}^{2x} - 1}{\mathrm{e}^{2x}+1}</annotation></semantics>
</math>
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{{InteractiveExample("JavaScript Demo: Math.tanh()")}}

```js interactive-example
console.log(Math.tanh(-1));
// Expected output: -0.7615941559557649

console.log(Math.tanh(0));
// Expected output: 0

console.log(Math.tanh(Infinity));
// Expected output: 1

console.log(Math.tanh(1));
// Expected output: 0.7615941559557649
```

## Syntax

```js-nolint
Math.tanh(x)
```

### Parameters

- `x`
  - : A number.

### Return value

The hyperbolic tangent of `x`.

## Description

Because `tanh()` is a static method of `Math`, you always use it as `Math.tanh()`, rather than as a method of a `Math` object you created (`Math` is not a constructor).

## Examples

### Using Math.tanh()

```js
Math.tanh(-Infinity); // -1
Math.tanh(-0); // -0
Math.tanh(0); // 0
Math.tanh(1); // 0.7615941559557649
Math.tanh(Infinity); // 1
```

## Specifications

{{Specifications}}

## Browser compatibility

{{Compat}}

## See also

- [Polyfill of `Math.tanh` in `core-js`](https://github.com/zloirock/core-js#ecmascript-math)
- {{jsxref("Math.acosh()")}}
- {{jsxref("Math.asinh()")}}
- {{jsxref("Math.atanh()")}}
- {{jsxref("Math.cosh()")}}
- {{jsxref("Math.sinh()")}}