We are pleased to announce the release candidate for Unicode® ICU 79. It updates to Unicode 18 (blog), including new characters and scripts, emoji, collation & IDNA changes, and corresponding APIs and implementations.
It also updates to CLDR 49 (beta blog) locale data with many additions and corrections.
Line break backwards-iteration performance has been significantly improved, fixing a long-standing regression.
C++ and Java implementations of the CLDR MessageFormat 2.0 specification have been updated to CLDR 49. Some of the API remains in technology preview.
ICU 79 and CLDR 49 are major releases, including a new version of Unicode and major locale data improvements.
- Details: ICU 79
- Download: releases/tag/release-79.1rc
- API docs (preliminary): follow the “Dev” links on unicode-org.github.io/icu-docs/
Please test this release candidate on your platforms and report bugs and regressions by Monday, 2026-oct-19, via the icu-support mailing list, and/or please find/submit error reports.
Please do not use this release candidate in production.
Attention: Future Changes
- We will phase out cross-version Java serialization compatibility guarantees for ICU4J starting with the ICU 80 release.
- Follow the link for details and other planned changes.