v143 · javascript

ICU version 77 (supporting Unicode 16)

The Unicode support library, International Components for Unicode (ICU), is upgraded from version 74.2 to version 77.1, adding support for Unicode 16 and updating locale data. Two changes could pose some risk for web applications that assume a specific format from the [Intl](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Internationalization)

concepts

  1. Unicode 16

    Live probes: render new Unicode 16 codepoints, segment text with Intl.Segmenter, and test regex Script_Extensions for the new scripts — all in your browser.

  2. Format drift

    The risk the change call-out: number, date, and relative-time formatters can shift across ICU upgrades. Side-by-side preview of Intl.NumberFormat, DateTimeFormat, and RelativeTimeFormat output for any locale.

  3. Emoji segmenter

    An interactive playground for the new ICU 77 grapheme cluster tables. Paste any text with mixed scripts, ZWJ joiners, skin-tone modifiers, and Unicode 16 newcomers and watch Intl.Segmenter split it into the right user-visible characters.

  4. Unicode 16 Explorer

    A code point lookup (hex or decimal) showing character, block, script, category, Unicode version, and UTF-16/UTF-8 encodings. A "Notable new in Unicode 16" panel with 15 entries (new emoji, Garay, Sunuwar, Todhri scripts) is each clickable. An Intl.Segmenter tester with grapheme/word/sentence tabs highlights Unicode 16 segments in green, and a version comparison table tracks segmentation changes across U14, U15, and U16.

why it shipped

The Unicode support library, International Components for Unicode (ICU), is upgraded from version 74.2 to version 77.1, adding support for Unicode 16 and updating locale data. Two changes could pose some risk for web applications that assume a specific format from the [Intl](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Internationalization)

references