HTML Dom Tutorial

Introduction to the manual

The HTML DOM defines standard methods for accessing and manipulating HTML documents. DOM expresses HTML documents in a tree structure.

Know the HTML DOM

DOM is the abbreviation of Document Object Model, which is the standard programming interface for processing extensible markup language recommended by the W3C organization. According to the W3C DOM specification, the DOM is a browser, platform, and language-independent interface that allows you to access other standard components in a page. Simply understood, the DOM resolves the conflict between Netscape's JavaScript and Microsoft's JavaScript, giving web designers and developers a standard way to access data, scripts, and presentation-level objects in their sites.


The DOM is a collection of nodes or pieces of information organized in a hierarchy. This hierarchy allows developers to navigate the tree looking for specific information. Analyzing that structure usually requires loading the entire document and constructing the hierarchy before any work can be done. Since it is based on the information hierarchy, the DOM is considered to be tree-based or object-based.

The HTML DOM defines standard methods for accessing and manipulating HTML documents.

HTML DOM renders HTML documents as a tree structure (node tree) with elements, attributes, and text.

Overview of the tutorial structure

This tutorial consists of 13 sections, describes the basic usage of HTML DOM in detail, and is accompanied by a large number of online trial-run examples to assist your learning, allowing you to easily master HTML DOM.

This tutorial contains:

1. HTML DOM Tutorial

2. Introduction to HTML DOM

3. HTML DOM Nodes

4. HTML DOM Methods

5. HTML DOM Attributes

6. HTML DOM Access

7. HTML DOM Modification

8. HTML DOM - Changing HTML Content

9. HTML DOM Elements

10. HTML DOM Events

11. HTML DOM Navigation

12. HTML DOM Summary

13. HTML DOM Examples

HTML DOM development and preparation before learning:

The history of the Document Object Model can be traced back to the "browser war" between Microsoft and Netscape in the late 1990s. The two sides fought for life and death in JavaScript and JScript, so they endowed the browser with powerful functions on a large scale. Microsoft has added a lot of exclusive things to the web page technology, including VBScript, ActiveX, and Microsoft's own DHTML format, etc., so that many web pages cannot be displayed normally using non-Microsoft platforms and browsers. DOM is a masterpiece that was brewed at that time.

In 1998, the W3C published the first-level DOM specification. This specification allows access and manipulation of each individual element in an HTML page. All browsers implement this standard, so DOM compatibility issues are almost invisible.

Before you start learning HTML DOM, you should have a basic understanding of the following:

HTML Tutorial "

CSS Tutorial "

JavaScript Tutorial "

In this tutorial, you'll learn how to manipulate HTML more efficiently through the Document Object Model (DOM) without the help of a DOM manipulation library. The code samples in the tutorial take you through modern DOM concepts by demonstrating how various node objects work.

Advantages and Disadvantages of HTML DOM


Strong ease of use, when using DOM, all XML document information will be stored in memory, and the traversal is simple, XPath is supported, and the ease of use is enhanced.


Inefficiency, slow parsing, high memory footprint, and almost impossible to use for large files. In addition, the low efficiency is also manifested in a lot of time consumption, because when using DOM for parsing, an object will be created for each element, attribute, processing-instrUCtion and comment of the document, so that the creation of a large number of objects used in the DOM mechanism and destruction will undoubtedly affect its efficiency.

Related URLs:

HTML DOM Reference Manual: 

W3C official website: