# Apache Arrow JS v21.2.0-rc1 — Apache Arrow JS 21.2.0 RC1

- Product: Apache Arrow JS (https://whatsnew.fyi/product/apache-arrow-js)
- Vendor: Apache
- Date: 2026-07-17
- Version: v21.2.0-rc1
- Original notes: https://github.com/apache/arrow-js/releases/tag/v21.2.0-rc1
- Permalink: https://whatsnew.fyi/product/apache-arrow-js/releases/v21.2.0-rc1
- Labels: Pre-release

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **added** — Add support for BinaryView and Utf8View types
- **fixed** — Fix precision loss in IntervalMonthDayNano nanosecond
- **fixed** — Resolve TS2352 type error in MapBuilder for TypeScript 5.6+

##### What's Changed
* chore: bump memfs from 4.39.0 to 4.48.1 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/301
* chore: bump @types/node from 24.5.2 to 24.7.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/304
* chore: bump google-closure-compiler from 20250903.0.0 to 20251001.0.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/303
* chore: bump typescript-eslint from 8.45.0 to 8.46.1 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/306
* chore: bump del from 8.0.0 to 8.0.1 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/307
* chore: bump @rollup/plugin-node-resolve from 16.0.1 to 16.0.3 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/312
* chore: bump webpack from 5.102.0 to 5.102.1 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/313
* chore: bump actions/setup-node from 5.0.0 to 6.0.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/314
* chore: bump actions/download-artifact from 5.0.0 to 6.0.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/316
* chore: bump actions/upload-artifact from 4.6.2 to 5.0.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/317
* chore: bump @types/node from 24.7.0 to 24.9.1 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/318
* chore: bump memfs from 4.48.1 to 4.49.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/319
* fix: Fix precision loss in IntervalMonthDayNano nanosecond by @GeorgeLeePatterson in https://github.com/apache/arrow-js/pull/321
* chore: bump del-cli from 6.0.0 to 7.0.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/328
* chore: bump eslint from 9.36.0 to 9.39.1 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/331
* chore: bump actions/checkout from 5.0.0 to 5.0.1 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/338
* chore: bump glob from 11.0.3 to 12.0.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/335
* chore: Use relative link for LICENSE.txt by @Divyanshu-s13 in https://github.com/apache/arrow-js/pull/339
* feat: Add support for BinaryView and Utf8View types by @GeorgeLeePatterson in https://github.com/apache/arrow-js/pull/320
* chore: bump actions/checkout from 5.0.1 to 6.0.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/343
* chore: bump webpack-bundle-analyzer from 4.10.2 to 5.0.1 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/342
* chore: bump webpack from 5.102.1 to 5.103.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/345
* chore: bump esbuild from 0.25.10 to 0.27.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/332
* chore: bump actions/setup-python from 6.0.0 to 6.1.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/347
* chore: bump actions/setup-node from 6.0.0 to 6.1.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/348
* chore: bump glob from 12.0.0 to 13.0.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/350
* chore: bump typescript-eslint from 8.46.1 to 8.49.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/351
* chore: bump actions/checkout from 6.0.0 to 6.0.1 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/349
* chore: bump actions/cache from 4.3.0 to 5.0.1 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/352
* chore: bump actions/upload-artifact from 5.0.0 to 6.0.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/353
* chore: bump actions/download-artifact from 6.0.0 to 7.0.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/354
* chore: bump typescript-eslint from 8.49.0 to 8.50.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/355
* chore: bump @rollup/plugin-alias from 5.1.1 to 6.0.0 by @dependabot[bot] in https://github.com/apache/arrow-js/pull/356
* chore: bump eslint-plugin-jest from 29.0.1 to 29.9.0 by @dependabot[bot]

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