# Next.js v16.3.0 — Release & Upgrade Intelligence
- **Product:** Next.js (https://nextjs.org)
- **Version:** v16.3.0
- **Released:** Aug 03, 2026
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/nextjs/updates/v16.3.0/

## Executive Summary (TL;DR)
Next.js v16.3.0. Source highlight: Check out the 16.3 announcement post to get an overview of the changes.

## New Features
- Turbopack: Add importModule() support to webpack loaders: #89630
- feat(node-streams): add config flag, define-env, and env precedence test: #90427
- Add per-slot error attribution for instant validation using slot markers and config depth preference: #91610
- Add module count field to module graph tracing spans: #91697
- turbopack-cli: add --persistent-caching flag for filesystem-backed cache: #91657
- Add `next internal post-build` CLI command for Turbopack database compaction: #91336

## Improvements
- [turbopack] Improve regressed build speed on cross-compiled MUSL: #91477
- turbo-tasks-backend: improve print_cache_item_size instrumentation: #91742
- Improve error message for deprecated `experimental.dynamicIO` config: #92081
- Improve revalidateTag JSDoc to include guidance about required second parameter: #92176
- Improve existing dev server error message to suggest using it: #92317
- use sorted inserts to improve builder performance: #91553

## Bug Fixes
- Update vendored lodash to 4.17.23 to fix CVE-2025-13465: #91558
- Fix invalid HTML response for route-level RSC requests in deployment adapter: #91541
- Fix(pages-router): restore Content-Length and ETag for /_next/data/ JSON responses: #90304
- turbo-persistence: fix mmap page alignment and improve error context in MetaFile::open_internal: #91640
- Fix missing route in otel spans without base-server: #91665
- Fix layout segment optimization: move app-page imports to server-utility transition: #91701

## Upgrade Command
```bash
npm install --save-exact next@16.3.0
```