--- title: Next.js 16.3 previews instant navigations, Deno 2.9... description: A developer news roundup covering several major releases. Next.js 16.3 preview introduces instant navigations and partial prefetching behind feature flags.... canonical: https://daily.dev/posts/next-js-16-3-previews-instant-navigations-deno-2-9-ships-desktop-apps-i0yfnaka3 twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Next.js 16.3 previews instant navigations, Deno 2.9 ships desktop apps | daily.dev og:description: A developer news roundup covering several major releases. Next.js 16.3 preview introduces instant navigations and partial prefetching behind feature flags.... og:url: https://daily.dev/posts/next-js-16-3-previews-instant-navigations-deno-2-9-ships-desktop-apps-i0yfnaka3 og:image: https://api.daily.dev/og/posts/i0YFNaKa3.png og:image:alt: Next.js 16.3 previews instant navigations, Deno 2.9 ships desktop apps og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Next.js 16.3 previews instant navigations, Deno 2.9 ships desktop apps **[Web Digest](https://daily.dev/sources/webdev_digest)** · 4 min read · 1 upvotes · 0 comments ## Summary A developer news roundup covering several major releases. Next.js 16.3 preview introduces instant navigations and partial prefetching behind feature flags. Deno 2.9 ships desktop app support via WebView/CEF, 2x faster cold startup, post-quantum crypto primitives, and npm lockfile migration. Vercel AI SDK 7 adds resumable WorkflowAgents, MCP sandboxing, and a v6 codemod. The jshttp/cookie library v2.0.0 breaks CommonJS support and renames core methods, potentially affecting Express and Fastify users. Also covered: ECMAScript 2026 feature set, v0 design system support, and a camaro XML-to-JSON performance benchmark. ## Content **TLDR:** Next.js 16.3 preview lands with a new partial prefetching system and SPA-like instant navigations, still behind feature flags. Deno 2.9 is a big release: desktop app support, 2x faster cold startup, post-quantum crypto, and first-class npm lockfile migration. Vercel's AI SDK 7 ships with resumable agents, MCP sandboxing, and a codemod for v6 migration. jshttp/cookie v2 goes ESM-only and renames its core methods, which will quietly break things. --- ## Next.js 16.3 preview: instant navigations and partial prefetching Next.js 16.3 is available now via npm install next@preview and introduces Instant Navigations — a system where routes either stream a loading shell via Suspense, serve cached UI via 'use cache', or block as before. The big architectural change is partial prefetching: instead of per-link prefetching, a single reusable shell per route is fetched once, cutting unnecessary network requests. Developer tooling includes slow-navigation dev errors (Instant Insights), a Navigation Inspector in DevTools, and an instant() helper for Playwright. Both cacheComponents and partialPrefetching flags must be enabled to try any of this. [Read more](https://daily.dev/posts/80NCBhRrp) ## Deno 2.9: desktop apps, 2x faster startup, post-quantum crypto Deno 2.9 is a substantial release. deno desktop lets you ship native desktop apps as single binaries using WebView (~68.5MB) or CEF (~309MB) backends, with support for Next.js, Astro, and Vite SSR. Cold startup drops from 34ms to 17ms, memory under load is 3x lower, and deno compile gains --bundle for smaller outputs. The test runner gets snapshot testing, parameterized tests via Deno.test.each, CI sharding, and coverage thresholds. Supply chain security adds a 24-hour minimum dependency age by default. Web Crypto expands with ML-KEM, ML-DSA, SLH-DSA, ChaCha20-Poly1305, and SHA-3. First-class migration from npm/pnpm/yarn/Bun lockfiles is also included. [Read more](https://daily.dev/feed-by-ids?id=8IwOPlspK&id=uT9HAOtcE) ## Vercel AI SDK 7: resumable agents, MCP sandboxing, v6 codemod AI SDK 7 is a major version with a lot of surface area. The headliners are WorkflowAgent (durable, resumable agents), HarnessAgent for integrating Claude Code and Codex, and MCP Apps support with sandboxed iframes. Provider-agnostic realtime WebSocket support and experimental video generation are also in. Telemetry gets a full rework with single-registration OpenTelemetry and per-step performance stats. Migration from v6 is automated via a codemod, which is the right call given the scope of changes. [Read more](https://daily.dev/posts/iz9c3resL) ## jshttp/cookie v2.0.0 goes ESM-only and renames parse/stringify The jshttp/cookie library — used under the hood in Express, Fastify, and a lot of middleware — just shipped v2.0.0 as ESM-only. Node.js 22+ can still require() ESM, but anything older loses CommonJS support. The rename is the other breaking change: parse becomes parseCookie and stringify becomes stringifySetCookie, with stringifySetCookie now only accepting object mode. If you're not on Node 22 yet and you depend on this package directly or transitively, this is worth checking before it bites you in a dependency update. [Read more](https://daily.dev/posts/ylIrT8pL0) --- ## Also notable - **ECMAScript 2026: seven features landing now, Temporal still ES2027:** ES2026 brings Map.prototype.getOrInsert(), Iterator.concat(), Array.fromAsync(), Math.sumPrecise(), Error.isError(), native Base64 on Uint8Array, and JSON.parse source text access — Temporal hits Stage 4 but is pushed to ES2027. [Read more](https://daily.dev/posts/1g1Ih5vO8) - **v0 now supports production design systems including Fluent, Polaris, and Carbon:** Vercel's v0 can now generate UI using the exact component libraries your product ships — Microsoft Fluent, Shopify Polaris, IBM Carbon, Palantir Blueprint, and Vercel Geist are confirmed working. [Read more](https://daily.dev/posts/E9iiLe0ki) - **Netlify bandwidth: a 4.5MB RSS feed fetched 2,700 times burned 50% of monthly quota in two days:** A developer traced half their monthly Netlify bandwidth to an RSS feed serving 20 years of full post bodies at 4.5MB raw; switching to summaries-only and capping at 25 entries dropped it to 25KB. [Read more](https://daily.dev/posts/PtB85XS1Z) - **Google's Modern Web Guidance injects up-to-date browser API context into coding agents:** Google's open-source Modern Web Guidance project ships a SKILL.md for Claude Code, Cursor, and GitHub Copilot that steers agents toward current APIs like the Popover API and CSS @starting-style instead of legacy JavaScript workarounds. [Read more](https://daily.dev/feed-by-ids?id=GcZ6rkQln&id=4Aikfv1hu) - **camaro XML-to-JSON library benchmarks at up to 14.5x faster than xml2js for large payloads:** camaro v2 binds to the C++ pugixml parser via WebAssembly, benchmarks at nearly 2x faster than txml and 14.5x faster than xml2js on large XML strings, and supports worker_threads for multi-core scaling. [Read more](https://daily.dev/posts/Y0aZVA0Te) --- Tags: [#webdev](https://daily.dev/tags/webdev), [#javascript](https://daily.dev/tags/javascript), [#nextjs](https://daily.dev/tags/nextjs), [#deno](https://daily.dev/tags/deno) [View this post on daily.dev](https://daily.dev/posts/next-js-16-3-previews-instant-navigations-deno-2-9-ships-desktop-apps-i0yfnaka3) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"DiscussionForumPosting","mainEntityOfPage":"https://daily.dev/posts/next-js-16-3-previews-instant-navigations-deno-2-9-ships-desktop-apps-i0yfnaka3","headline":"Next.js 16.3 previews instant navigations, Deno 2.9 ships desktop apps","text":"A developer news roundup covering several major releases. 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