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For Yarn 2+ docs and migration guide, see yarnpkg.com.

Package detail

fast-xml-parser

NaturalIntelligence81.3mMIT4.5.1TypeScript support: included

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

fast, xml, json, parser, xml2js, x2js, xml2json, js, cli, validator, validate, transformer, assert, js2xml, json2xml, html

readme

fast-xml-parser

[![NPM quality][quality-image]][quality-url] Coverage Status Try me NPM total downloads

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


ads-thePowerGlassesBook I had recently published a book, The Power Glasses. Please have a look. Your feedback would be helpful. You can mail me for a free copy.

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fxp_sponsors Hiroki Kokubun

Users

more

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


Main Features

FXP logo
  • Validate XML data syntactically
  • Parse XML to JS Object
  • Build XML from JS Object
  • Compatible to node js packages, in browser, and in CLI (click try me button above for demo)
  • Faster than any other pure JS implementation.
  • It can handle big files (tested up to 100mb).
  • Controlled parsing using various options
  • XML Entities, HTML entities, and DOCTYPE entites are supported.
  • unpaired tags (Eg <br> in HTML), stop nodes (Eg <script> in HTML) are supported.
  • You can restore almost same XML from JSON
  • Supports comments
  • It can preserve Order of tags in JS object
  • You can control if a single tag should be parsed into array.
  • Supports parsing of PI (Processing Instruction) tags with XML declaration tags
  • And many more other features.

v5

I developed v5 in Apr 2023. And I didn't get the chance to complete all the features. I've ensured that new features don't impact performance. With v5, you have more control on parsing output. Check docs for syntax help and basic understanding.

Please leave a comment in discussion forum for your suggestions and if you really need v5.

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

Example

As CLI command

$ fxparser some.xml

In a node js project

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

<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

v3v4v5
documents
  1. Getting Started
  2. XML Parser
  3. XML Builder
  4. XML Validator
  5. Entities
  6. HTML Document Parsing
  7. PI Tag processing
  1. Getting Started
  2. Features
  3. Options
  4. Output Builders
  5. Value Parsers

note: version 5 is released with version 4 tfor experimental use. Based on it's demand, it'll be developed and the features can be different in final release.

Performance

negative means error

XML Parser

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

XML Builder

* Y-axis: requests per second

Usage Trend

Usage Trend of fast-xml-parser

NPM Usage Trend of fast-xml-parser

Supporters

Contributors

This project exists thanks to all the people who contribute. [Contribute].

Backers

Thank you to all our backers! 🙏 [Become a backer]

License

  • MIT License

Donate $5

changelog

Note: If you find missing information about particular minor version, that version must have been changed without any functional change in this library.

4.5.1 / 2024-12-15

  • Fix empty tag key name for v5 (#697). no impact on v4
  • Fixes entity parsing when used in strict mode (#699)

4.5.0 / 2024-09-03

  • feat #666: ignoreAttributes support function, and array of string or regex (By ArtemM)

4.4.1 / 2024-07-28

  • v5 fix: maximum length limit to currency value
  • fix #634: build attributes with oneListGroup and attributesGroupName (#653)(By Andreas Naziris)
  • fix: get oneListGroup to work as expected for array of strings (#662)(By Andreas Naziris)

4.4.0 / 2024-05-18

  • fix #654: parse attribute list correctly for self closing stop node.
  • fix: validator bug when closing tag is not opened. (#647) (By Ryosuke Fukatani)
  • fix #581: typings; return type of tagValueProcessor & attributeValueProcessor (#582) (By monholm)

4.3.6 / 2024-03-16

  • Add support for parsing HTML numeric entities (#645) (By Jonas Schade )

4.3.5 / 2024-02-24

  • code for v5 is added for experimental use

4.3.4 / 2024-01-10

  • fix: Don't escape entities in CDATA sections (#633) (By wackbyte)

4.3.3 / 2024-01-10

  • Remove unnecessary regex

4.3.2 / 2023-10-02

4.3.1 / 2023-09-24

  • revert back "Fix typings for builder and parser to make return type generic" to avoid failure of existing projects. Need to decide a common approach.

4.3.0 / 2023-09-20

  • Fix stopNodes to work with removeNSPrefix (#607) (#608) (By [Craig Andrews]https://github.com/candrews))
  • Fix #610 ignore properties set to Object.prototype
  • Fix typings for builder and parser to make return type generic (By Sarah Dayan)

4.2.7 / 2023-07-30

  • Fix: builder should set text node correctly when only textnode is present (#589) (By qianqing)
  • Fix: Fix for null and undefined attributes when building xml (#585) (#598). A null or undefined value should be ignored. (By Eugenio Ceschia)

4.2.6 / 2023-07-17

  • Fix: Remove trailing slash from jPath for self-closing tags (#595) (By Maciej Radzikowski)

4.2.5 / 2023-06-22

  • change code implementation

4.2.4 / 2023-06-06

  • fix security bug

4.2.3 / 2023-06-05

  • fix security bug

4.2.2 / 2023-04-18

  • fix #562: fix unpaired tag when it comes in last of a nested tag. Also throw error when unpaired tag is used as closing tag

4.2.1 / 2023-04-18

  • fix: jpath after unpaired tags

4.2.0 / 2023-04-09

  • support updateTag parser property

4.1.4 / 2023-04-08

  • update typings to let user create XMLBuilder instance without options (#556) (By Patrick)
  • fix: IsArray option isn't parsing tags with 0 as value correctly #490 (#557) (By Aleksandr Murashkin)
  • feature: support oneListGroup to group repeated children tags udder single group

4.1.3 / 2023-02-26

  • fix #546: Support complex entity value

4.1.2 / 2023-02-12

  • Security Fix

4.1.1 / 2023-02-03

  • Fix #540: ignoreAttributes breaks unpairedTags
  • Refactor XML builder code

4.1.0 / 2023-02-02

  • Fix '<' or '>' in DTD comment throwing an error. (#533) (By Adam Baker)
  • Set "eNotation" to 'true' as default

4.0.15 / 2023-01-25

  • make "eNotation" optional

4.0.14 / 2023-01-22

  • fixed: add missed typing "eNotation" to parse values

4.0.13 / 2023-01-07

4.0.12 / 2022-11-19

  • fix typescript

4.0.11 / 2022-10-05

  • fix #501: parse for entities only once

4.0.10 / 2022-09-14

4.0.9 / 2022-07-10

  • fix #470: stop-tag can have self-closing tag with same name
  • fix #472: stopNode can have any special tag inside
  • Allow !ATTLIST and !NOTATION with DOCTYPE
  • Add transformTagName option to transform tag names when parsing (#469) (By Erik Rothoff Andersson)

4.0.8 / 2022-05-28

  • Fix CDATA parsing returning empty string when value = 0 (#451) (By ndelanou)
  • Fix stopNodes when same tag appears inside node (#456) (By patrickshipe)
  • fix #468: prettify own properties only

4.0.7 / 2022-03-18

  • support CDATA even if tag order is not preserved
  • support Comments even if tag order is not preserved
  • fix #446: XMLbuilder should not indent XML declaration

4.0.6 / 2022-03-08

  • fix: call tagValueProcessor only once for array items
  • fix: missing changed for #437

4.0.5 / 2022-03-06

  • fix #437: call tagValueProcessor from XML builder

4.0.4 / 2022-03-03

  • fix #435: should skip unpaired and self-closing nodes when set as stopnodes

4.0.3 / 2022-02-15

4.0.2 / 2022-02-04

  • builder supports suppressUnpairedNode
  • parser supports ignoreDeclaration and ignorePiTags
  • fix: when comment is parsed as text value if given as <!--> ... #423
  • builder supports decoding &

4.0.1 / 2022-01-08

  • fix builder for pi tag
  • fix: support suppressBooleanAttrs by builder

4.0.0 / 2022-01-06

  • Generating different combined, parser only, builder only, validator only browser bundles
  • Keeping cjs modules as they can be imported in cjs and esm modules both. Otherwise refer esm branch.

4.0.0-beta.8 / 2021-12-13

  • call tagValueProcessor for stop nodes

4.0.0-beta.7 / 2021-12-09

  • fix Validator bug when an attribute has no value but '=' only
  • XML Builder should suppress unpaired tags by default.
  • documents update for missing features
  • refactoring to use Object.assign
  • refactoring to remove repeated code

4.0.0-beta.6 / 2021-12-05

  • Support PI Tags processing
  • Support suppressBooleanAttributes by XML Builder for attributes with value true.

4.0.0-beta.5 / 2021-12-04

  • fix: when a tag with name "attributes"

4.0.0-beta.4 / 2021-12-02

  • Support HTML document parsing
  • skip stop nodes parsing when building the XML from JS object
  • Support external entites without DOCTYPE
  • update dev dependency: strnum v1.0.5 to fix long number issue

4.0.0-beta.3 / 2021-11-30

  • support global stopNodes expression like "*.stop"
  • support self-closing and paired unpaired tags
  • fix: CDATA should not be parsed.
  • Fix typings for XMLBuilder (#396)(By Anders Emil Salvesen)
  • supports XML entities, HTML entities, DOCTYPE entities

⚠️ 4.0.0-beta.2 / 2021-11-19

  • rename attrMap to attibutes in parser output when preserveOrder:true
  • supports unpairedTags

⚠️ 4.0.0-beta.1 / 2021-11-18

  • Parser returns an array now
    • to make the structure common
    • and to return root level detail
  • renamed cdataTagName to cdataPropName
  • Added commentPropName
  • fix typings

⚠️ 4.0.0-beta.0 / 2021-11-16

  • Name change of many configuration properties.
    • attrNodeName to attributesGroupName
    • attrValueProcessor to attributeValueProcessor
    • parseNodeValue to parseTagValue
    • ignoreNameSpace to removeNSPrefix
    • numParseOptions to numberParseOptions
    • spelling correction for suppressEmptyNode
  • Name change of cli and browser bundle to fxparser
  • isArray option is added to parse a tag into array
  • preserveOrder option is added to render XML in such a way that the result js Object maintains the order of properties same as in XML.
  • Processing behaviour of tagValueProcessor and attributeValueProcessor are changes with extra input parameters
  • j2xparser is renamed to XMLBuilder.
  • You need to build XML parser instance for given options first before parsing XML.
  • fix #327, #336: throw error when extra text after XML content
  • fix #330: attribute value can have '\n',
  • fix #350: attrbiutes can be separated by '\n' from tagname

3.21.1 / 2021-10-31

  • Correctly format JSON elements with a text prop but no attribute props ( By haddadnj )

3.21.0 / 2021-10-25

  • feat: added option rootNodeName to set tag name for array input when converting js object to XML.
  • feat: added option alwaysCreateTextNode to force text node creation (by: @massimo-ua)
  • ⚠️ feat: Better error location for unclosed tags. (by @Gei0r)
    • Some error messages would be changed when validating XML. Eg
      • { InvalidXml: "Invalid '[ \"rootNode\"]' found." }{InvalidTag: "Unclosed tag 'rootNode'."}
      • { InvalidTag: "Closing tag 'rootNode' is expected inplace of 'rootnode'." }{ InvalidTag: "Expected closing tag 'rootNode' (opened in line 1) instead of closing tag 'rootnode'."}
  • ⚠️ feat: Column in error response when validating XML
    {
    "code": "InvalidAttr",
    "msg":  "Attribute 'abc' is repeated.",
    "line": 1,
    "col": 22
    }

3.20.1 / 2021-09-25

  • update strnum package

3.20.0 / 2021-09-10

  • Use strnum npm package to parse string to number
    • breaking change: long number will be parsed to scientific notation.

3.19.0 / 2021-03-14

  • License changed to MIT original
  • Fix #321 : namespace tag parsing

3.18.0 / 2021-02-05

  • Support RegEx and function in arrayMode option
  • Fix #317 : validate nested PI tags

3.17.4 / 2020-06-07

  • Refactor some code to support IE11
  • Fix: <tag > space as attribute string

3.17.3 / 2020-05-23

  • Fix: tag name separated by \n \t
  • Fix: throw error for unclosed tags

3.17.2 / 2020-05-23

  • Fixed an issue in processing doctype tag
  • Fixed tagName where it should not have whitespace chars

3.17.1 / 2020-05-19

  • Fixed an issue in checking opening tag

3.17.0 / 2020-05-18

  • parser: fix '<' issue when it comes in aatr value
  • parser: refactoring to remove dependency from regex
  • validator: fix IE 11 issue for error messages
  • updated dev dependencies
  • separated benchmark module to sub-module
  • breaking change: comments will not be removed from CDATA data

3.16.0 / 2020-01-12

  • validaor: fix for ampersand characters (#215)
  • refactoring to support unicode chars in tag name
  • update typing for validator error

3.15.1 / 2019-12-09

  • validaor: fix multiple roots are not allowed

3.15.0 / 2019-11-23

  • validaor: improve error messaging
  • validator: add line number in case of error
  • validator: add more error scenarios to make it more descriptive

3.14.0 / 2019-10-25

  • arrayMode for XML to JS obj parsing

3.13.0 / 2019-10-02

  • pass tag/attr name to tag/attr value processor
  • inbuilt optional validation with XML parser

3.12.21 / 2019-10-02

  • Fix validator for unclosed XMLs
  • move nimnjs dependency to dev dependency
  • update dependencies

3.12.20 / 2019-08-16

  • Revert: Fix #167: '>' in attribute value as it is causing high performance degrade.

3.12.19 / 2019-07-28

  • Fix js to xml parser should work for date values. (broken: tagValueProcessor will receive the original value instead of string always) (breaking change)

3.12.18 / 2019-07-27

  • remove configstore dependency

3.12.17 / 2019-07-14

  • Fix #167: '>' in attribute value

3.12.16 / 2019-03-23

  • Support a new option "stopNodes". (#150) Accept the list of tags which are not required to be parsed. Instead, all the nested tag and data will be assigned as string.
  • Don't show post-install message

3.12.12 / 2019-01-11

  • fix : IE parseInt, parseFloat error

3.12.11 / 2018-12-24

  • fix #132: "/" should not be parsed as boolean attr in case of self closing tags

3.12.9 / 2018-11-23

  • fix #129 : validator should not fail when an atrribute name is 'length'

3.12.8 / 2018-11-22

  • fix #128 : use 'attrValueProcessor' to process attribute value in json2xml parser

3.12.6 / 2018-11-10

  • Fix #126: check for type

3.12.4 / 2018-09-12

  • Fix: include tasks in npm package

3.12.3 / 2018-09-12

  • Fix CLI issue raised in last PR

3.12.2 / 2018-09-11

  • Fix formatting for JSON to XML output
  • Migrate to webpack (PR merged)
  • fix cli (PR merged)

3.12.0 / 2018-08-06

  • Support hexadecimal values
  • Support true number parsing

3.11.2 / 2018-07-23

  • Update Demo for more options
  • Update license information
  • Update readme for formatting, users, and spelling mistakes
  • Add missing typescript definition for j2xParser
  • refactoring: change filenames

3.11.1 / 2018-06-05

  • fix #93: read the text after self closing tag

3.11.0 / 2018-05-20

  • return defaultOptions if there are not options in buildOptions function
  • added localeRange declaration in parser.d.ts
  • Added support of cyrillic characters in validator XML
  • fixed bug in validator work when XML data with byte order marker

3.10.0 / 2018-05-13

  • Added support of cyrillic characters in parsing XML to JSON

3.9.11 / 2018-05-09

3.3.10 / 2018-04-23

  • fix #77 : parse even if closing tag has space before '>'
  • include all css & js lib in demo app
  • remove babel dependencies until needed

3.3.9 / 2018-04-18

  • fix #74 : TS2314 TypeScript compiler error

3.3.8 / 2018-04-17

  • fix #73 : IE doesn't support Object.assign

3.3.7 / 2018-04-14

3.3.6 / 2018-03-21

  • change arrow functions to full notation for IE compatibility

3.3.5 / 2018-03-15

3.3.4 / 2018-03-14

  • remove dependency on "he" package
  • refactor code to separate methods in separate files.
  • draft code for transforming XML to json string. It is not officially documented due to performance issue.

3.3.0 / 2018-03-05

  • use common default options for XML parsing for consistency. And add parseToNimn method.
  • update nexttodo
  • update README about XML to Nimn transformation and remove special notes about 3.x release
  • update CONTRIBUTING.ms mentioning nexttodo
  • add negative case for XML PIs
  • validate xml processing instruction tags https://github.com/NaturalIntelligence/fast-xml-parser/issues/62
  • nimndata: handle array with object
  • nimndata: node with nested node and text node
  • nimndata: handle attributes and text node
  • nimndata: add options, handle array
  • add xml to nimn data converter
  • x2j: direct access property with tagname
  • update changelog
  • fix validator when single quote presents in value enclosed with double quotes or vice versa
  • Revert "remove unneded nimnjs dependency, move opencollective to devDependencies and replace it with more light opencollective-postinstall" This reverts commit d47aa7181075d82db4fee97fd8ea32b056fe3f46.
  • Merge pull request: https://github.com/NaturalIntelligence/fast-xml-parser/issues/63 from HaroldPutman/suppress-undefined Keep undefined nodes out of the XML output : This is useful when you are deleting nodes from the JSON and rewriting XML.

3.2.4 / 2018-03-01

  • fix #59 fix in validator when open quote presents in attribute value
  • Create nexttodo.md
  • exclude static from bitHound tests
  • add package lock

3.2.3 / 2018-02-28

  • Merge pull request from Delagen/master: fix namespaces can contain the same characters as xml names

3.2.2 / 2018-02-22

  • fix: attribute xmlns should not be removed if ignoreNameSpace is false
  • create CONTRIBUTING.md

3.2.1 / 2018-02-17

  • fix: empty attribute should be parsed

3.2.0 / 2018-02-16

  • Merge pull request : Dev to Master
  • Update README and version
  • j2x:add performance test
  • j2x: Remove extra empty line before closing tag
  • j2x: suppress empty nodes to self closing node if configured
  • j2x: provide option to give indentation depth
  • j2x: make optional formatting
  • j2x: encodeHTMLchat
  • j2x: handle cdata tag
  • j2x: handle grouped attributes
  • convert json to xml
    • nested object
    • array
    • attributes
    • text value
  • small refactoring
  • Merge pull request: Update cli.js to let user validate XML file or data
  • Add option for rendering CDATA as separate property

3.0.1 / 2018-02-09

  • fix CRLF: replace it with single space in attributes value only.

3.0.0 / 2018-02-08

  • change online tool with new changes
  • update info about new options
  • separate tag value processing to separate function
  • make HTML decoding optional
  • give an option to allow boolean attributes
  • change cli options as per v3
  • Correct comparison table format on README
  • update v3 information
  • some performance improvement changes
  • Make regex object local to the method and move some common methods to util
  • Change parser to
    • handle multiple instances of CDATA
    • make triming of value optionals
    • HTML decode attribute and text value
    • refactor code to separate files
  • Ignore newline chars without RE (in validator)
  • validate for XML prolog
  • Validate DOCTYPE without RE
  • Update validator to return error response
  • Update README to add detail about V3
  • Separate xmlNode model class
  • include vscode debug config
  • fix for repeated object
  • fix attribute regex for boolean attributes
  • Fix validator for invalid attributes 2.9.4 / 2018-02-02
  • Merge pull request: Decode HTML characters
  • refactor source folder name
  • ignore bundle / browser js to be published to npm 2.9.3 / 2018-01-26
  • Merge pull request: Correctly remove CRLF line breaks
  • Enable to parse attribute in online editor
  • Fix testing demo app test
  • Describe parsing options
  • Add options for online demo 2.9.2 / 2018-01-18
  • Remove check if tag starting with "XML"
  • Fix: when there are spaces before / after CDATA

2.9.1 / 2018-01-16

  • Fix: newline should be replaced with single space
  • Fix: for single and multiline comments
  • validate xml with CDATA
  • Fix: the issue when there is no space between 2 attributes
  • Fix: https://github.com/NaturalIntelligence/fast-xml-parser/issues/33: when there is newline char in attr val, it doesn't parse
  • Merge pull request: fix ignoreNamespace
    • fix: don't wrap attributes if only namespace attrs
    • fix: use portfinder for run tests, update deps
    • fix: don't treat namespaces as attributes when ignoreNamespace enabled

2.9.0 / 2018-01-10

  • Rewrite the validator to handle large files. Ignore DOCTYPE validation.
  • Fix: When attribute value has equal sign

2.8.3 / 2017-12-15

  • Fix: when a tag has value along with subtags

2.8.2 / 2017-12-04

  • Fix value parsing for IE

2.8.1 / 2017-12-01

  • fix: validator should return false instead of err when invalid XML

2.8.0 / 2017-11-29

  • Add CLI option to ignore value conversion
  • Fix variable name when filename is given on CLI
  • Update CLI help text
  • Merge pull request: xml2js: Accept standard input
  • Test Node 8
  • Update dependencies
  • Bundle readToEnd
  • Add ability to read from standard input

2.7.4 / 2017-09-22

  • Merge pull request: Allow wrap attributes with subobject to compatible with other parsers output

2.7.3 / 2017-08-02

  • fix: handle CDATA with regx

2.7.2 / 2017-07-30

  • Change travis config for yarn caching
  • fix validator: when tag property is same as array property
  • Merge pull request: Failing test case in validator for valid SVG

2.7.1 / 2017-07-26

  • Fix: Handle val 0

2.7.0 / 2017-07-25

  • Fix test for arrayMode
  • Merge pull request: Add arrayMode option to parse any nodes as arrays

2.6.0 / 2017-07-14

  • code improvement
  • Add unit tests for value conversion for attr
  • Merge pull request: option of an attribute value conversion to a number (textAttrConversion) the same way as the textNodeConversion option does. Default value is false.

2.5.1 / 2017-07-01

  • Fix XML element name pattern
  • Fix XML element name pattern while parsing
  • Fix validation for xml tag element

2.5.0 / 2017-06-25

  • Improve Validator performance
  • update attr matching regex
  • Add perf tests
  • Improve atrr regex to handle all cases

2.4.4 / 2017-06-08

  • Bug fix: when an attribute has single or double quote in value

2.4.3 / 2017-06-05

  • Bug fix: when multiple CDATA tags are given
  • Merge pull request: add option "textNodeConversion"
  • add option "textNodeConversion"

2.4.1 / 2017-04-14

  • fix tests
  • Bug fix: preserve initial space of node value
  • Handle CDATA

2.3.1 / 2017-03-15

  • Bug fix: when single self closing tag
  • Merge pull request: fix .codeclimate.yml
  • Update .codeclimate.yml - Fixed config so it does not error anymore.
  • Update .codeclimate.yml

2.3.0 / 2017-02-26

  • Code improvement
  • add bithound config
  • Update usage
  • Update travis to generate bundle js before running tests
  • 1.Browserify, 2. add more tests for validator
  • Add validator
  • Fix CLI default parameter bug

2.2.1 / 2017-02-05

  • Bug fix: CLI default option