JavaScript and ECMA Specification

JavaScript and the ECMA

JavaScript is a cross-platform, object-oriented scripting language developed by Netscape was first used in Netscape browsers. However, Netscape was working with European Computer Manufacturers Association (ECMA) to deliver a standardized, international programming language based on core JavaScript. ECMA is an international standards association for information and communication systems. This standardized version of JavaScript, called ECMAScript, behaves the same way in all applications that support the standard. Companies can use the open standard language to develop their implementation of JavaScript. The first version of the ECMA standard was documented in the ECMA-262 specification. The ECMA-262 standard is also approved by the ISO (International Organization for Standardization) as ISO-16262.

The following table describes the relationship between JavaScript and ECMA versions.

JavaScript version Relationship to ECMA version
JavaScript 1.1 ECMA-262 is based on JavaScript 1.1.
JavaScript 1.2 ECMA-262 was not complete when JavaScript 1.2 was released. JavaScript 1.2 is not fully compatible with ECMA-262 for the following reasons:

Netscape developed additional features in JavaScript 1.2 that were not considered for ECMA-262.

ECMA-262 adds two new features: internationalization using Unicode, and uniform behavior across all platforms. Several features of JavaScript 1.2, such as the Date object, were platform-dependent and used platform-specific behavior.
JavaScript 1.3 JavaScript 1.3 is fully compatible with ECMA-262.

JavaScript 1.3 resolved the inconsistencies that JavaScript 1.2 had with ECMA-262, while keeping all the additional features of JavaScript 1.2 except == and !=, which were changed to conform with ECMA-262. These additional features, including some new features of JavaScript 1.3 that are not part of ECMA, are under consideration for the second version of the ECMA specification.
For example, JavaScript 1.2 and 1.3 support regular expressions, which are not included in ECMA-262. The second version of the ECMA specification had not been finalized when JavaScript 1.3 was released.
JavaScript 1.4 (Works on Netscape server only)
JavaScript 1.5 JavaScript 1.5 is compatible with ECMA-262 Edition 3. This is a major update as per as security and libraries are a concern. Better compatibility with the modern browser is another important aspect of it.

JavaScript version and supported browser versions

The following table covers the Javascript versions, release date and supported browser versions.

Version Release date Netscape
Opera Safari Google
1.0 March 1996 2.0 3.0
1.1 August 1996 3.0
1.2 June 1997 4.0-4.05
1.3 October 1998 4.06-4.7 4.0
1.4 Netscape
1.5 November 2000 6.0 1.0 5.5
1.6 November 2005 1.5
1.7 October 2006 2.0 6
1.8 June 2008 3.0
1.8.1 3.5
1.8.2 June 22, 2009 3.6

Test JavaScript Version

The following web document returns the version of Javascript supported by your browser.

Click here to View the version


<!DOCTYPE html>
<meta charset="utf-8" />
<title>JavaScript version checking</title>
<h1 style="color: red">JavaScript version checking</h1>
<hr />
<script type="text/javascript">
var jsbrowver = 1.0;
<script language='Javascript1.1'>
var jsbrowver = 1.1;
<script language='Javascript1.2'>
var jsbrowver = 1.2;
<script language='Javascript1.3'>
var jsbrowver = 1.3;
<script language='Javascript1.4'>
var jsbrowver = 1.4;
<script language='Javascript1.5'>
var jsbrowver = 1.5;
<script language='Javascript1.6'>
var jsbrowver = 1.6;
<script language='Javascript1.7'>
var jsbrowver = 1.7;
<script language='Javascript1.8'>
var jsbrowver = 1.8;
<script type='text/javascript'>
alert('Supported Javascript Version : ' + jsbrowver);

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