Releases: unicode-org/icu
Release list
icu4x/2026-07-01/79.x
Tag for updated ICU4X data
ICU 78.3
Unicode® ICU 78.3 is a maintenance update on top of ICU 78 and 78.2, mostly for the CLDR 48.2 bug fixes. In addition, it fixes a C++ code point iterator bug, and updates to timezone data 2026a.
Details: ICU 78
Download: releases/tag/release-78.3
Maven: com.ibm.icu / icu4j / version 78.3
The next major release of ICU will be ICU 79, planned for October. It will update to CLDR 49 and Unicode 18.
ICU 78.2
We are pleased to announce the release of Unicode® ICU 78.2. It updates to CLDR 48.1. These are maintenance releases for ICU 78 and CLDR 48, with limited sets of bug fixes and no API or structural changes.
ICU 78.2 also includes a small number of bug fixes, as well as a minor update for time zone data (tzdata) version 2025c (2025-dec) ICU-23296.
Changes in ICU 78.2:
- C++
ucasemap_setLocale()better handles errors in reading uninitialized memory from a bogus locale ID - Java & C++ yield the correct long time zone name for Europe/Dublin
- C++ fixes a build issue on the clang-cl compiler related to the 'dllexport' attribute
- C++ fixes a build issue when operator+ on UnicodeString is used with non-ICU code when ICU headers are included
- List of all tickets fixed in ICU 78.2
For details, please see https://unicode-org.github.io/icu/download/78.html.
ICU 78.1
We are pleased to announce the release of Unicode® ICU 78. It updates to Unicode 17 (blog), including new characters and scripts, emoji, collation & IDNA changes, and corresponding APIs and implementations.
It also updates to CLDR 48 (beta blog) locale data with new locales, and various additions and corrections.
- Details: ICU 78.
- Download: releases/tag/release-78.1
- Maven: com.ibm.icu / icu4j / version 78.1
In Java, there is a draft new Segmenter API which is easier and safer to use than BreakIterator.
In C++, there is a new set of APIs for Unicode string (UTF-8/16/32) code point iteration that works seamlessly with modern C++ iterators and ranges.
The Java implementation of the CLDR MessageFormat 2.0 specification has been updated to CLDR 48. The core API has been upgraded to “draft”, while the Data Model API remains in technology preview.
The C++ implementation of MessageFormat 2.0 is at CLDR 47 level and remains in technology preview.
ICU 78 and CLDR 48 are major releases, including a new version of Unicode and major locale data improvements.
ICU 78 RC
We are pleased to announce the release candidate for Unicode® ICU 78. It updates to Unicode 17 (blog), including new characters and scripts, emoji, collation & IDNA changes, and corresponding APIs and implementations.
It also updates to CLDR 48 (beta blog) locale data with new locales, and various additions and corrections.
In Java, there is a draft new Segmenter API which is easier and safer to use than BreakIterator.
In C++, there is a new set of APIs for Unicode string (UTF-8/16/32) code point iteration that works seamlessly with modern C++ iterators and ranges.
The Java implementation of the CLDR MessageFormat 2.0 specification has been updated to CLDR 48. The core API has been upgraded to “draft”, while the Data Model API remains in technology preview.
The C++ implementation of MessageFormat 2.0 is at CLDR 47 level and remains in technology preview.
ICU 78 and CLDR 48 are major releases, including a new version of Unicode and major locale data improvements.
For details, please see https://unicode-org.github.io/icu/download/78.html.
Please test this release candidate on your platforms and report bugs and regressions by Monday, 2025-oct-27, via the icu-support mailing list, and/or please find/submit error reports.
Please do not use this release candidate in production.
The preliminary API reference documents are published on unicode-org.github.io/icu-docs/ – follow the “Dev” links there.
icu4x/2025-05-21/77.x
Tag for updated ICU4X data
icu4x/2025-05-01/77.x
ICU-23054 Bump the github-actions group with 2 updates See #3490
ICU 77.1
We are pleased to announce the release of Unicode® ICU 77. It updates to CLDR 47 (beta blog) locale data with new locales, and various additions and corrections.
ICU 77 is mostly focused on bug fixes, segmentation conformance, and other refinements.
The Java technology preview implementation of the CLDR MessageFormat 2.0 specification has been updated to incorporate the CLDR 46.1 spec plus most but not all of the CLDR 47 changes.
The C++ technology preview implementation of MessageFormat 2.0 is not yet quite up to date with CLDR 46.1.
Please note that for ICU 78 (2025-oct) we are planning to (a) upgrade from Java 8 to Java 11, and (b) remove the ICU4J Locale Service Provider. See the ICU 77 page for details.
ICU 77 RC
We are pleased to announce the release candidate for Unicode® ICU 77. It updates to CLDR 47 (alpha blog) locale data with new locales, and various additions and corrections.
ICU 77 is mostly focused on bug fixes, segmentation conformance, and other refinements.
The Java technology preview implementation of the CLDR MessageFormat 2.0 specification has been updated to incorporate the CLDR 46.1 spec plus most but not all of the CLDR 47 changes.
The C++ technology preview implementation of MessageFormat 2.0 is not yet quite up to date with CLDR 46.1.
For details, please see https://unicode-org.github.io/icu/download/77.html.
Please test this release candidate on your platforms and report bugs and regressions by Monday, 2025-mar-10, via the icu-support mailing list, and/or please find/submit error reports.
Please do not use this release candidate in production.
The preliminary API reference documents are published on unicode-org.github.io/icu-docs/ – follow the “Dev” links there.
icu4x/2024-12-16/76.x
ICU-22920 Fix raw type warnings in icu4j core tests