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This is a comparison of data serialization formats, different ways to convert complex objects to sequences of bits. It does not include markup languages used exclusively as document file formats.

The links to the original specifications are referenced in the table column Specification.

[edit]Overview

Name	Creator/Maintainer	Based on	Standardized?	Specification	Binary?	Human-readable?	Includesreferencesupport?e	Schema/IDL?	Standard APIs
ASN.1	ISO, IEC, ITU-T	N/A	Yes	ISO/IEC 8824; X.680 series of ITU-T Recommendations	Yes (BER, PER, or custom via ECN)	Yes (XER, or custom viaECN)	Partial f	Yes (built-in)	N/A
BSON	MongoDB	JSON	Yes	BSON Specification	Yes	No	No	No	No
Comma-separated values (CSV)	RFC author: Yakov Shafranovich	N/A	Partial (myriad informal variants used)	RFC 4180 (among others)	No	Yes	No	No	No
D-Bus Message Protocol	freedesktop.org	N/A	Yes	D-Bus Specification	Yes	Yes (Type Signatures)	No	No	Yes (see D-Bus)
JSON	Douglas Crockford	JavaScript syntax	Yes	RFC 4627	No, but seeBSON	Yes	No	Partial (Kwalify,Rx, JSON Schema Proposal)	No
Netstrings	Dan Bernstein	N/A	Yes	netstrings.txt	Yes	Yes	No	No	No
OGDL	Rolf Veen	?	Yes	1.0 Working draft	Yes (Binary 1.0 Working draft)	Yes	Yes (Path 1.0 Working draft)	Yes (Schema WD)
Property list	NeXT (creator) Apple (maintainer)	?	Partial	Public DTD for XML format	Yesa	Yesb	No	?	Cocoa,CoreFoundation,OpenStep,GnuStep
Protocol Buffers	Google	N/A	Partial	Developer Guide: Encoding	Yes	Partiald	No	Yes (built-in)
S-expressions	Internet Draft author: Ron Rivest	Lisp,Netstrings	Partial (largely de facto)	"S-Expressions"Internet Draft	No	Yes	No	No
Structured Data eXchange Formats	IETF	N/A	Yes	RFC 3072	Yes	No	No	No
Thrift	Facebook (creator) Apache (maintainer)	N/A	No	Original whitepaper	Yes	Partialc	No	Yes (built-in)
eXternal Data Representation	IETF	N/A	Yes	RFC 4506	Yes	No	Yes	Yes	?
XML	W3C	SGML	Yes	W3C Recommendations: 1.0 (Fifth Edition) 1.1 (Second Edition)	Partial (Binary XML)	Yes	Yes (XPointer,XPath)	Yes (XML schema)	DOM, SAX,XQuery, XPath
YAML	Clark Evans, Ingy döt Net, and Oren Ben-Kiki	XML, C,Python,Perl,Email	Yes	Version 1.2	No	Yes	Yes	Partial (Kwalify,Rx, built-in language type-defs)	No

• a. ^ The current default format is binary.
• b. ^ The "classic" format is plain text, and an XML format is also supported.
• c. ^ Theoretically possible due to abstraction, but no implementation is included.
• d. ^ The primary format is binary but a text format is available.^[1]
• e. ^ Means that generic tools/libraries know how to encode, decode, and dereference a reference to another piece of data in the same document. A tool may require the IDL file, but no more. Excludes custom, non-standardized referencing techniques.
• f. ^ ASN.1 does offer OIDs, a standard format for globally-unique identifiers. However, there is no standard for "marking"/"tagging" an arbitrary piece of data in a document with an OID. There is also no standard format for locally-unique identifiers within a document. Therefore, a generic ASN.1 tool/library can not automatically encode/decode/resolve references within a document without help from custom-written program code.

[edit]Syntax comparison of human-readable formats

<SeqOfUnrelatedDatatypes>
    <isMarried>true</isMarried>
    <hobby />
    <velocity>-42.1e7</velocity>
    <bookname>A to Z</bookname>
    <bookname>We said, "no".</bookname>
</SeqOfUnrelatedDatatypes>

<person>
    <isMarried>true</isMarried>
    <hobby />
    <height>1.85</height>
    <name>Bob Peterson</name>
</person>

<competition>
    <measurement>
        <name>John</name>
        <height>3.14</height>
    </measurement>
    <measurement>
        <name>Jane</name>
        <height>2.718</height>
    </measurement>
</competition>

42,1
A to Z,1,2,3

true
null
-42.1e7
"A to Z"

42
  true
"A to Z"
  1
  2
  3

42
  true
"A to Z", (1, 2, 3)

{
    "42" = <*BY>;
    "A to Z" = ( <*I1>, <*I2>, <*I3> );
}

<array>
    <true />
    <real>-42.1e7</real>
    <string>A to Z</string>
</array>

<dict>
    <key>42</key>
    <true />
    <key>A to Z</key>
    <array>
        <integer>1</integer>
        <integer>2</integer>
        <integer>3</integer>
    </array>
</dict>

- y
-
- -42.1e7
- A to Z

42: y
A to Z: [1, 2, 3]

<array>
  <element type="boolean">true</element>
  <element type="null"/>
  <element type="float">-42.1e7</element>
  <element type="string">A to Z</element>
</array>

<associative-array>
  <entry>
    <key type="integer">42</key>
    <value type="boolean">true</value>
  </entry>
  <entry>
    <key type="string">A to Z</key>
    <value>
      <array>
        <element type="integer" val="1"/>
        <element type="integer" val="2"/>
        <element type="integer" val="3"/>
      <array>
    </value>
  </entry>
</associative-array>

• a. ^ One possible encoding; the specification document does not specifically give an encoding for this datatype.
• b. ^ The RFC CSV specification only deals with delimiters, newlines, and quote characters; it does not directly deal with serializing programming data structures.
• c. ^ The netstrings specification only deals with nested byte strings; anything else is outside the scope of the specification.
• d. ^ XML in and of itself is not a data serialization language, but many data serialization formats have been derived from it; as such, there are many different ways, in addition to those shown, to serialize programming data structures into XML.
• e. ^ This syntax is not compatible with the Internet-Draft, but is used by some dialects of Lisp.

[edit]Comparison of binary formats

[edit]See also

• Comparison of document markup languages

[edit]Notes

[edit]External links

• XML-QL Proposal discussing XML benefits
• When to use XML
• "XML Sucks" on c2.com
• Daring to Do Less with XML