# parse5
> **NOTE:** By default all functions operate with [tree format](tree-adapter/default/interface-list.md) produced
> by the default tree adapter. Tree format can be changed by providing custom [tree adapter](tree-adapter/interface.md) implementation.
### Functions
* [parse](#parse)
* [parseFragment](#parsefragment)
* [serialize](#serialize)
### parse
▸ **parse**(html: _`string`_, options?: _[ParserOptions](options/parser-options.md)_): Document
Parses an HTML string.
_**example**_:
```js
const parse5 = require('parse5');
const document = parse5.parse('Hi there!');
console.log(document.childNodes[1].tagName); //> 'html'
```
**Parameters:**
| Param | Type | Description |
| ------------------ | -------------------------------------------------------------------------------------------------------------- | ------------------ |
| html | `string` | Input HTML string. |
| `Optional` options | [ParserOptions](options/parser-options.md) | Parsing options. |
**Returns:** Document
---
### parseFragment
▸ **parseFragment**(fragmentContext: _Element_, html: _`string`_, options?: _[ParserOptions](options/parser-options.md)_): DocumentFragment
▸ **parseFragment**(html: _`string`_, options?: _[ParserOptions](options/parser-options.md)_): DocumentFragment
Parses an HTML fragment.
_**example**_:
```js
const parse5 = require('parse5');
const documentFragment = parse5.parseFragment('');
console.log(documentFragment.childNodes[0].tagName); //> 'table'
// Parses the html fragment in the context of the parsed element.
const trFragment = parser.parseFragment(documentFragment.childNodes[0], '| Shake it, baby |
');
console.log(trFragment.childNodes[0].childNodes[0].tagName); //> 'td'
```
**Parameters:**
| Param | Type | Description |
| -------------------------- | -------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------- |
| `Optional` fragmentContext | Element | Parsing context element. If specified, given fragment will be parsed as if it was set to the context element's \`innerHTML\` property. |
| html | `string` | Input HTML fragment string. |
| `Optional` options | [ParserOptions](options/parser-options.md) | Parsing options. |
**Returns:** DocumentFragment
---
### serialize
▸ **serialize**(node: _Node_, options?: _[SerializerOptions](options/serializer-options.md)_): `string`
Serializes an AST node to an HTML string.
_**example**_:
```js
const parse5 = require('parse5');
const document = parse5.parse('Hi there!');
// Serializes a document.
const html = parse5.serialize(document);
// Serializes the element content.
const str = parse5.serialize(document.childNodes[1]);
console.log(str); //> 'Hi there!'
```
**Parameters:**
| Param | Type | Description |
| ------------------ | ---------------------------------------------------------------------------------------------------------------------- | ---------------------- |
| node | Node | Node to serialize. |
| `Optional` options | [SerializerOptions](options/serializer-options.md) | Serialization options. |
**Returns:** `string`
---