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2023-06-15: ICU 73.2 is now available. Maintenance release with changes for GB18030 compliance, English AM/PM spaces, word segmentation around @ sign, etc. See Downloading ICU > ICU 73.

2023-04-13: ICU 73 is now available. It updates to CLDR 43 locale data with various additions and corrections.

ICU 73 improves Japanese and Korean short-text line breaking, reduces C++ memory use in date formatting, and promotes the Java person name formatter from tech preview to draft.

For details, see Downloading ICU > ICU 73.

2022-10-20: ICU 72 is now available. It updates to Unicode 15, including new characters, scripts, emoji, and corresponding API constants. It also updates to CLDR 42 locale data with various additions and corrections. ICU 72 adds technology preview implementations for person name formatting, as well as for a new version of message formatting based on a proposed draft Unicode specification. For details, see Downloading ICU > ICU 72.

🔴 Do you need ICU to work on EBCDIC platforms? 🔴

Special Notice About Branch Renaming: On 2021-March-24 we renamed the master branch to main branch (

If you have a local git clone of the repo, you need to rename your default branch:

$ git branch -m master main

$ git fetch origin

$ git branch -u origin/main main

If you use the master branch in your personal fork on GitHub, rename that branch to main as well. (If you go to your fork, GitHub should show you a pop-up dialog with a link to the settings.)

2021-03-18: ICU 69.1 released. It updates to CLDR 39. This release includes significant improvements for measurement unit formatting and number formatting in general.

2020-12-17: ICU 68.2 released. It updates to CLDR 38. New features including locale-dependent smart unit preferences (road distance, temperature, etc.) and locale ID canonicalization conformant with CLDR. (ICU 68 was released on 2020-10-28. Maintenance release 68.2 includes some bug fixes.)

What is ICU?

ICU is a mature, widely used set of C/C++ and Java libraries providing Unicode and Globalization support for software applications. ICU is widely portable and gives applications the same results on all platforms and between C/C++ and Java software. ICU is released under a nonrestrictive open source license that is suitable for use with both commercial software and with other open source or free software.

Here are a few highlights of the services provided by ICU:

And much more. Refer to the ICU User Guide for details.

Why Unicode?

Unicode (and the parallel ISO 10646 standard) defines the character set necessary for efficiently processing text in any language and for maintaining text data integrity. In addition to global character coverage, the Unicode standard is unique among character set standards because it also defines data and algorithms for efficient and consistent text processing. This simplifies high-level processing and ensures that all conformant software produces the same results. The widespread adoption of Unicode over the last decade made text data truly portable and formed a cornerstone of the Internet.

Globalized software, based on Unicode, maximizes market reach and minimizes cost. Globalized software is built and installed once and yet handles text for and from users worldwide and accomodates their cultural conventions. It minimizes cost by eliminating per-language builds, installations, and maintenance updates.

Why ICU4C?

The C and C++ languages and many operating system environments do not provide full support for Unicode and standards-compliant text handling services. Even though some platforms do provide good Unicode text handling services, portable application code can not make use of them. The ICU4C libraries fills in this gap. ICU4C provides an open, flexible, portable foundation for applications to use for their software globalization requirements. ICU4C closely tracks industry standards, including Unicode and CLDR (Common Locale Data Repository).

Why ICU4J?

Java provides a very strong foundation for global programs, and IBM and the ICU team played a key role in providing globalization technology into Sun's Java. But because of its long release schedule, Java cannot always keep up-to-date with evolving standards. The ICU team continues to extend Java's Unicode and internationalization support, focusing on improving performance, keeping current with the Unicode standard, and providing richer APIs, while remaining as compatible as possible with the original Java text and internationalization API design.

See Why Use ICU4J?


New versions of ICU4JNI are no longer being created. If you need the functionality of ICU4JNI, you should consider migrating to ICU4J.

Who Uses ICU?

The following is a list of products, companies and organizations reported to be using ICU. If you have any feedback on this list (corrections, additions, or details), please contact us (on icu-support).

Companies and Organizations using ICU

ABAS Software, Adobe, Amazon (Kindle), Amdocs, Apache, Appian, Apple, Argonne National Laboratory, Avaya, BAE Systems Geospatial eXploitation Products, BEA, BluePhoenix Solutions, BMC Software, Boost, BroadJump, Business Objects, caris, CERN, CouchDB, Debian Linux, Dell, Eclipse, eBay, EMC Corporation, ESRI, Facebook (HHVM), Firebird RDBMS, FreeBSD, Gentoo Linux, Google, GroundWork Open Source, GTK+, Harman/Becker Automotive Systems GmbH, HP, Hyperion, IBM, Inktomi, Innodata Isogen, Informatica, Intel, Interlogics, IONA, IXOS, Jikes, Library of Congress, LibreOffice, Mathworks, Microsoft, Mozilla, Netezza, Node.js, Oracle (Solaris, Java), Lawson Software, Leica Geosystems GIS & Mapping LLC, Mandrake Linux, OCLC, Progress Software, Python, QNX, Rogue Wave, SAP, SIL, SPSS, Software AG, SuSE, Sybase, Symantec, Teradata (NCR), ToolAware, Trend Micro, Virage, webMethods, Wikimedia Foundation [Wikipedia] MediaWiki application servers, Wine, WMS Gaming, XyEnterprise, Yahoo!, Vuo, and many others.

Apache Projects

Harmony, Lucene search library, OpenOffice, PDFBox library, Solr search engine server, Tika metadata toolkits, Xalan XSLT, Xerces XML

Products from IBM

DB2, Lotus, Websphere, Tivoli, Rational, AIX, i/OS, z/OS

Ascential Software, Cloudant, Cognos, PSD Print Architecture, COBOL, Host Access Client, InfoPrint Manager, Informix GLS, Language Analysis Systems, Lotus Notes, Lotus Extended Search, Lotus Workplace, WebSphere Message Broker, NUMA-Q, OTI, OmniFind, Pervasive Computing WECMS, Rational Business Developer and Rational Application Developer, SS&S Websphere Banking Solutions, Tivoli Presentation Services, Tivoli Identity Manager, WBI Adapter/ Connect/Modeler and Monitor/ Solution Technology Development/WBI-Financial TePI, Websphere Application Server/ Studio Workload Simulator/Transcoding Publisher, XML Parser.

Products from Google

Web Search, Google+, Chrome/Chrome OS, Android, Adwords, Google Finance, Google Maps, Blogger, Google Analytics, Google Groups, and others.

Products from Apple

macOS (OS & applications), iOS (iPhone, iPad, iPod touch), watchOS & tvOS, Safari for Windows & other Windows applications and related support, Apple Mobile Device Support in iTunes for Windows.

Products from Microsoft

Windows Bridge for iOS (link), Windows 10 - Creators Update, Visual Studio 2017 [Electron], Visual Studio Code [Electron], ChakraCore

Products from Harman/Becker

The following car brands are using ICU via the Harman/Becker automotive software: Alfa Romeo, Audi, Bentley, BMW, Buick, more...

Products from Adobe

Creative Cloud apps and Document Cloud

Related Projects

There are also some related projects that wrap the existing functionality of ICU.