---
title: Performance
summary: Provides access to performance-related information for the current page. It's part of the High Resolution Time API, but is enhanced by the Performance Timeline API, the Navigation Timing API, the User Timing API, and the Resource Timing API.
url: https://www.fastly.com/documentation/reference/compute/sdks/javascript/js-compute/globals/interface.Performance/
---

**Kind:** Interface  
**Module:** [globals](https://www.fastly.com/documentation/reference/compute/sdks/javascript/js-compute/globals/)  
**Package:** @fastly/js-compute 4.0.1  
**Source:** https://github.com/fastly/js-compute-runtime/blob/70cf30af4e657879b2d1e7eafab880e39e3a3f7d/types/globals.d.ts#L2652

Extends `EventTarget`.

Provides access to performance-related information for the current page. It's part of the High Resolution Time API, but is enhanced by the Performance Timeline API, the Navigation Timing API, the User Timing API, and the Resource Timing API.

[MDN Reference](https://developer.mozilla.org/docs/Web/API/Performance)

## Constructor

**Source:** https://github.com/fastly/js-compute-runtime/blob/70cf30af4e657879b2d1e7eafab880e39e3a3f7d/types/globals.d.ts#L2664

```javascript
new Performance()
```

## Properties

### timeOrigin

**Type:** `DOMHighResTimeStamp`  
**Flags:** read-only  
**Source:** https://github.com/fastly/js-compute-runtime/blob/70cf30af4e657879b2d1e7eafab880e39e3a3f7d/types/globals.d.ts#L2654

[MDN Reference](https://developer.mozilla.org/docs/Web/API/Performance/timeOrigin)

## Methods

### now

**Source:** https://github.com/fastly/js-compute-runtime/blob/70cf30af4e657879b2d1e7eafab880e39e3a3f7d/types/globals.d.ts#L2656

```javascript
now(): DOMHighResTimeStamp
```

[MDN Reference](https://developer.mozilla.org/docs/Web/API/Performance/now)

**Returns**

`DOMHighResTimeStamp`