# fast-xml-parser

> Validate XML, Parse XML, Build XML without C/C++ based libraries

Latest version **5.11.1** (published 2026-08-27) · MIT license · 0 weekly downloads

## Install

```sh
npm install fast-xml-parser
pnpm add fast-xml-parser
yarn add fast-xml-parser
bun add fast-xml-parser
```

Provides the command `fxparser`.

## Health

**Score 75/100 (B)** — status: active.

Positive: has types; esm support; no vulnerabilities; has provenance; recently updated; high maintenance score; high quality score.

Warnings: low downloads.

## Facts

| | |
|---|---|
| Version | 5.11.1 |
| Published | 2026-08-27 |
| First published | 2017-01-28 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | ESM + CommonJS |
| Dependencies | 6 |
| Unpacked size | 1.3 MB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| Provenance | attested (GitHub Actions) |
| GitHub stars | 3139 |
| Author | Amit Gupta |
| Maintainers | amitgupta |
| Keywords | fast, xml, json, parser, xml2js, x2js, xml2json, js, validator, validate, transformer, assert, js2xml, json2xml, html |

## Links

- npm: https://www.npmjs.com/package/fast-xml-parser
- Repository: https://github.com/NaturalIntelligence/fast-xml-parser
- Homepage: https://github.com/NaturalIntelligence/fast-xml-parser#readme
- Issues: https://github.com/NaturalIntelligence/fast-xml-parser/issues
- Funding: https://github.com/sponsors/NaturalIntelligence
- npm.io page: https://npm.io/package/fast-xml-parser

## Dependencies (6)

- [strnum](https://npm.io/package/strnum.md) ^2.4.2
- [is-unsafe](https://npm.io/package/is-unsafe.md) ^2.0.0
- [xml-naming](https://npm.io/package/xml-naming.md) ^0.3.0
- [fast-xml-builder](https://npm.io/package/fast-xml-builder.md) ^1.2.0
- [@nodable/entities](https://npm.io/package/@nodable/entities.md) ^3.0.0
- [path-expression-matcher](https://npm.io/package/path-expression-matcher.md) ^1.6.2

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## Recent versions

- 5.11.1 (latest) — 2026-08-27
- 4.5.7 (legacy) — 2026-07-02
- 5.11.0 — 2026-08-16
- 5.10.1 — 2026-07-16
- 5.10.0 — 2026-07-11
- 5.9.3 — 2026-06-19
- 5.9.2 — 2026-06-17
- 5.9.1 — 2026-06-17
- 5.9.0 — 2026-06-15
- 5.8.0 — 2026-05-12
- 5.7.3 — 2026-05-05
- 5.7.2 — 2026-04-24
- 5.7.1 — 2026-04-17
- 5.7.0 — 2026-04-17
- 5.6.0 — 2026-04-15
- … 185 more at https://npm.io/package/fast-xml-parser/versions

## README

# [fast-xml-parser](https://www.npmjs.com/package/fast-xml-parser)

[![NPM total downloads](https://img.shields.io/npm/dt/fast-xml-parser.svg)](https://npm.im/fast-xml-parser)

Validate XML, Parse XML to JS Object, or Build XML from JS Object without C/C++ based libraries and no callback.

<img align="right" src="static/img/fxp_logo.png" width="180px" alt="FXP logo"/>

* Validate XML data syntactically. Use [detailed-xml-validator](https://github.com/NaturalIntelligence/detailed-xml-validator/) to verify business rules.
* Parse XML to JS Objects and vice versa
* Common JS, ESM, and browser compatible
* Faster than any other pure JS implementation.

It can handle big files (tested up to 100mb). XML Entities, HTML entities, and DOCTYPE entites are supported. Unpaired tags (Eg `<br>` in HTML), stop nodes (Eg `<script>` in HTML) are supported. It can also preserve Order of tags in JS object

> **IMPORTANT**: It is recommended to use [fast-xml-validator](https://github.com/NaturalIntelligence/fast-xml-validator) instead of inbuilt validator.

# Before using this library

- [Flexible-XML-Parser](https://github.com/nodable/flexible-xml-parser) is 1.25 times faster than this library when not preserving order of tags. Takes less memory when processing big files. Supports incomplete XML/HTML. And output is highly customizable. Build whatever you want. So if you're fine with some extra configuration then try it out.
- [@nodable/sax](https://github.com/nodable/sax) is a SAX parser based on [Flexible-XML-Parser](https://github.com/nodable/flexible-xml-parser). 3-4 times faster than `sax`  and support all features of base package like incomplete input, streams, skipping certain tags from processing etc.
- [fast-xml-validator](https://github.com/NaturalIntelligence/fast-xml-validator) is separated from this package. Has many features. Faster. You can exvlude particular tag from validation. And much more.
- [fast-xml-builder](https://github.com/NaturalIntelligence/fast-xml-builder) is a XML to JS Object builder used in this package in past. Now, it supports more features, and faster. So, recommend to use it directly.


---
# Your Support, Our Motivation

Please join [Discord community](https://discord.gg/X4Qp9u6Vz) for pre release announcements and discussions.

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- [Text2Chart](https://solothought.com/text2chart/flow): interactive flow chart out of simple text. -->

## Financial Support

Sponsor this project

<a href="https://github.com/sponsors/NaturalIntelligence"> 
  <img src="https://raw.githubusercontent.com/NaturalIntelligence/ThankYouBackers/main/github_sponsor.png" width="180" />
</a>
<a href="https://opencollective.com/fast-xml-parser/donate" target="_blank">
  <img src="https://opencollective.com/fast-xml-parser/donate/button@2x.png?color=blue" width=180 />
</a>
<br>
<br>
<br>

> This is a donation. No goods or services are expected in return. Any requests for refunds for those purposes will be rejected.

## Users

<a href="https://github.com/renovatebot/renovate" title="renovate" ><img src="https://avatars1.githubusercontent.com/u/38656520" width="60px" ></a>
<a href="https://vmware.com/" title="vmware" > <img src="https://avatars0.githubusercontent.com/u/473334" width="60px" ></a>
<a href="https://opensource.microsoft.com/" title="microsoft" > <img src="https://avatars0.githubusercontent.com/u/6154722" width="60px" ></a>
<a href="http://ibm.github.io/" title="IBM" > <img src="https://avatars2.githubusercontent.com/u/1459110" width="60px" ></a>
<a href="http://www.smartbear.com" title="SmartBear Software" > <img src="https://avatars2.githubusercontent.com/u/1644671" width="60px" ></a>
<a href="http://nasa.github.io/" title="NASA" > <img src="https://avatars0.githubusercontent.com/u/848102" width="60px" ></a>
<a href="https://github.com/prettier" title="Prettier" > <img src="https://avatars0.githubusercontent.com/u/25822731" width="60px" ></a>
<a href="http://brain.js.org/" title="brain.js" > <img src="https://avatars2.githubusercontent.com/u/23732838" width="60px" ></a>
<a href="https://github.com/aws" title="AWS SDK" > <img src="https://avatars.githubusercontent.com/u/2232217" width="60px" ></a>
<a href="http://www.fda.gov/" title="Food and Drug Administration " > <img src="https://avatars2.githubusercontent.com/u/6471964" width="60px" ></a>
<a href="http://www.magento.com/" title="Magento" > <img src="https://avatars2.githubusercontent.com/u/168457" width="60px" ></a>
<a href="https://github.com/SAP" title="SAP" > <img src="https://user-images.githubusercontent.com/7692328/204835214-d9d25b58-e3df-408d-87a3-c7d36b578ee4.png" width="60px" ></a>
<a href="https://github.com/postmanlabs" title="postman" > <img src="https://user-images.githubusercontent.com/7692328/204835529-e9e290ad-696a-49ad-9d34-08e955704715.png" width="60px" ></a>
<a href="https://github.com/react-native-community" title="React Native Community" > <img src="https://avatars.githubusercontent.com/u/20269980?v=4" width="60px" ></a>
<a href="https://github.com/googleapis" title="Google APIs" > <img src="https://avatars.githubusercontent.com/u/16785467?v=4" width="60px" ></a>
<a href="https://github.com/langchain-ai" title="Langchain AI" > <img src="https://avatars.githubusercontent.com/u/126733545?v=4" width="60px" ></a>
<a href="https://github.com/withastro" title="Astro websie builder" > <img src="https://avatars.githubusercontent.com/u/44914786?v=4" width="60px" ></a>
<a href="https://github.com/baidu" title="Baidu" > <img src="https://avatars.githubusercontent.com/u/13245940?v=4" width="60px" ></a>
[more](./USERs.md)

<small>The list of users are mostly published by Github or communicated directly. Feel free to contact if you find any information wrong.</small>

---

# More about this library

## How to use

To use as package dependency
`$ npm install fast-xml-parser` 
or 
`$ yarn add fast-xml-parser`

To use as system command
`$ npm install fast-xml-parser -g` 

To use it on a **webpage** include it from a [CDN](https://cdnjs.com/libraries/fast-xml-parser)

**Example**

As CLI command
```bash
$ fxparser some.xml
```

In a node js project
```js
const { XMLParser, XMLBuilder, XMLValidator} = require("fast-xml-parser");

const parser = new XMLParser();
let jObj = parser.parse(XMLdata);

const builder = new XMLBuilder();
const xmlContent = builder.build(jObj);
```

In a HTML page
```html
<script src="path/to/fxp.min.js"></script>
:
<script>
  const parser = new fxparser.XMLParser();
  parser.parse(xmlContent);
</script>
```

Bundle size

| Bundle Name        | Size |
| ------------------ | ---- |
| fxbuilder.min.js   | 6.5K |
| fxparser.min.js    | 20K  |
| fxp.min.js         | 26K  |
| fxvalidator.min.js | 5.7K |

## Documents
<table>
  <tr><td>v3</td><td>v4 and v5</td><td>v6</td></tr>
  <tr>
    <td>
      <a href="./docs/v3/docs.md">documents</a>
    </td>
    <td><ol>
      <li><a href="./docs/v4,v5/1.GettingStarted.md">Getting Started</a></li>
      <li><a href="./docs/v4,v5/2.XMLparseOptions.md">XML Parser</a></li>
      <li><a href="./docs/v4,v5/3.XMLBuilder.md">XML Builder</a></li>
      <li><a href="./docs/v4,v5/4.XMLValidator.md">XML Validator</a></li>
      <li><a href="./docs/v4,v5/5.Entities.md">Entities</a></li>
      <li><a href="./docs/v4,v5/6.HTMLParsing.md">HTML Document Parsing</a></li>
      <li><a href="./docs/v4,v5/7.PITags.md">PI Tag processing</a></li>
      <li><a href="./docs/v4,v5/8.PathExpression.md">Path Expression</a></li>
    </ol></td>
    <td><ol>
      <li></li><a href="./docs/v6/1.GettingStarted.md">Getting Started</a></li>
    </ol></td>
  </tr>
</table>

**note**: 
- Version 6 is released with version 4 for experimental use. Based on its demand, it'll be developed and the features can be different in final release.
- Version 5 has the same functionalities as version 4.

## Performance
<small>negative means error</small>

### XML Parser

<img align="left" src="./docs/imgs/XMLParser_v4.png" width="45%" />
<img src="./docs/imgs/XMLParser_large_v4.png" width="47%" />

* Y-axis: requests per second
* X-axis: File size

### XML Builder

<img src="./docs/imgs/XMLBuilder_v4.png" width="50%" />
* Y-axis: requests per second

<!-- [![](static/img/ni_ads_ads.gif)](https://github.com/NaturalIntelligence/ads/) -->

---

## Usage Trend

[Usage Trend of fast-xml-parser](https://npm-compare.com/fast-xml-parser#timeRange=THREE_YEARS)
  
<a href="https://npm-compare.com/fast-xml-parser#timeRange=THREE_YEARS" target="_blank">
  <img src="https://npm-compare.com/img/npm-trend/THREE_YEARS/fast-xml-parser.png" width="50%" alt="NPM Usage Trend of fast-xml-parser" />
</a>

# Supporters
#### Contributors

This project exists thanks to [all](graphs/contributors) the people who contribute. [[Contribute](docs/CONTRIBUTING.md)].

<a href="graphs/contributors"><img src="https://opencollective.com/fast-xml-parser/contributors.svg?width=890&button=false" /></a>


#### Backers from Open collective

Thank you to all our backers! 🙏 [[Become a backer](https://opencollective.com/fast-xml-parser#backer)]

<a href="https://opencollective.com/fast-xml-parser#backers" target="_blank"><img src="https://opencollective.com/fast-xml-parser/backers.svg?width=890"></a>



# License
* MIT License

![Donate $5](static/img/donation_quote.png)

---
_Source: https://npm.io/package/fast-xml-parser · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._