#performance

Oxlint apps_v1.72.0 and oxfmt apps_v0.57.0, both published on 2026-06-29, close out the v0.138 crates cycle predicted in the [v1.71 release notes](/articles/2026-06-23--oxlint-v1-71-oxfmt-v0-56). The crates release (crates_v0.138.0, also 2026-06-29) unifies the old and new AstBuilder APIs (#23876, #23834, #23831, with legacy methods marked `#[deprecated]`), renames `AllocatorAccessor` to `GetAllocator` and switches its `allocator` method to take `&self` (#23675, #23676), makes `Str` and `Ident` methods take `&GetAllocator` (#23781), adds `transformer_plugins: Support typeof define keys` for vue-i18n and similar macros (#23605, Alexander Lichter), and ships the headline perf entry of the cycle: `minifier: memoize value_type to remove its O(n^2) re-walk on long binary chains` (#23929, Dunqing), which turns a 20k-term arithmetic-addition chain from 6,118 ms to 4.7 ms (~1300x) and a real-world antd.js bundle from 78.1 ms to 65.4 ms. Oxlint v1.72.0 ships 3 features (React `no-unknown-property` suggestion #23936, AstBuilder unification #23875, `eslint/no-restricted-import` schema #23642), 18 bug fixes, and 23 performance entries. Oxfmt v0.57.0 carries two BREAKING changes that retire the Prettier fallback for CSS/LESS/SCSS and GraphQL files: `Format parser:css,less,scss files + css-in-js by oxc_formatter_css` (#23321, leaysgur) and `Support draft syntax with removing prettier fallback` (#23326, leaysgur), both landing on top of the new `oxc_formatter_css` (#23320) and `oxc_formatter_graphql` (#23317) crates.

Deno 2.9 (Bartek Iwańczuk, published 2026-06-25 on deno.com/blog/v2.9) is the largest Deno release of the cycle. Cold start drops from 34.2 ms to 17.3 ms (1.98x), peak RSS on the Deno.serve realworld workload drops 2.2x (142 MB → 64 MB) and 3.1x on 1 MiB bodies (197 MB → 63 MB), and Deno.serve throughput climbs 1.27x realworld (56.8k → 72.4k req/s), 1.11x plaintext, and 1.18x on 1 MiB bodies. Supply chain hardening: npm minimum-release-age is enabled by default with a 24h window (PR #35458), and a new opt-in no-downgrade trust policy (PR #34927) refuses to resolve any version whose trust evidence (staged publish, trusted publishing, provenance attestation) is weaker than the strongest evidence on any earlier-published version of the same package. Test runner parity: built-in t.assertSnapshot() (#35139), Deno.test.each (#34938), --shard for CI fan-out (#35057), retry and repeats (#35053), change-aware --changed and --related (#35199), and coverage thresholds (#35056). Lockfile interop: deno install seeds deno.lock from package-lock.json, pnpm-lock.yaml, yarn.lock, or bun.lock (#34296, #35330, #35346, #35350, #35394), pnpm-workspace.yaml auto-migrates to deno.json / package.json (#34993), and git merge conflict markers in deno.lock auto-resolve (#34726). Plus: deno desktop graduates from experimental (the June 16 PR #33441), deno link / deno unlink / deno list / deno watch subcommands, stable --unsafe-proto (#34738), Web Locks API (#31166), Happy Eyeballs v2 (RFC 8305) (#31726), navigator.userAgentData (#34743), the WebCrypto Modern Algorithms proposal (ML-KEM, ML-DSA, SLH-DSA, ChaCha20-Poly1305, SHA-3 family, KMAC, Argon2) (#34447, #34448, #34914, #35223), Node 26.3.0 compat (#34746, #34747), Node-API v10 (#35270), and CSS module imports under --unstable-raw-imports (#35093). 165+ PRs land in this cycle.

Node.js 24.18.0 'Krypton' (LTS), published 2026-06-23, ships the Buffer.poolSize 64 KiB default that landed on Current in 26.3.0, adds RFC 9861's TurboSHAKE and KangarooTwelve to Web Cryptography (PR #62183, 1,521 additions, 13 files), adds http.writeInformation for arbitrary 1xx status codes (PR #63155, 306 additions, 7 files), exposes V8 precise coverage start to the JS inspector runtime (commit 8c989ec4a3), adds JWK import-export for the ML-KEM and SLH-DSA post-quantum key types (PR #62706, 842 additions, 39 files), lands the BoringSSL-side wiring of ML-DSA, ML-KEM, ChaCha20-Poly1305, and AES-KW for Web Crypto (PR #63255), hardens WebCrypto against prototype pollution (PR #63363), aligns crypto.diffieHellman key argument names and accepts key data inputs (PR #62527), reverts the 24.16.0 'noop pause/resume on destroyed streams' behavior (PR #63834), and ships a single-line hotfix on 22.23.1 that backs out an http agent change from the 06-18 security release that triggered an unexpected re-stream.

Vite 8.1.0 stable, published 2026-06-23 by the Vite Team (announcing-vite8-1), graduates Bundled Dev Mode from an experimental flag into a documented --experimental-bundle entry point (15x faster cold start on a 10k React-component app, 10x faster full reloads, 3x faster cold-start rendering and 40% faster full reloads reported by Linear), stabilises the WASM ESM Integration direct .wasm imports and build.chunkImportMap that shipped in 8.1-beta on 2026-06-15, brings Lightning CSS one step closer to default by adding external-CSS-in-CSS and plugin file dependencies, bumps Rolldown to 1.1.2 (1.1.3 follows the same day), pins rolldown with a tilde range so patch releases flow through without a Vite PR, extends server.fs.deny with .npmrc, .yarnrc.yml, and *.{key,p12,pfx,cer,der}, and emits a runtime warning when envFile: false is used (the deprecation is already documented in the types).

Oxlint apps_v1.71.0 and oxfmt apps_v0.56.0, both published on 2026-06-22, close out the v0.137 crates cycle. Oxlint v1.71 picks up the new treeshaking pure typed arrays minifier pass (#23469), the prefer-query-selector compound selector fix, 28 lint bug fixes (most of them Yunfei He's fixer-rewrite work), 13 performance entries anchored on a bucketed rule dispatch refactor (#23450, #23452, #23482-#23486, #23489, #23492), and the oxlint Tokio-on-LSP-only startup (#23447). Oxfmt v0.56.0 ships 9 bug fixes (CRLF normalization for `// @ts-ignore` suppressed text in #23701 and #23702, the member-chain panic fix #23698, the default-export-with-type-cast preservation #23697) and 3 formatter performance entries that remove arena copies on bigint, numeric-literal, and string-literal text. v1.71 is the first apps release since v1.70.0 on 2026-06-15, and the last one before the v0.138 crates release that will land on Monday 2026-06-29.

SWC v1.15.43, published on 2026-06-22 with swc_core v71.0.3, ships the experimental Rust React Compiler as a configurable SWC transform via .swcrc jsc.transform.reactCompiler (PR #11917, 54 files, 12,986 additions); fixes a silent template literal minifier bug where `compress` dropped text after the left template's last interpolation when concatenating two template literals (#11939); gates Number(x) -> +x on both `unsafe: true` AND `unsafe_math: true` to match terser v4.3.11+ (#11944, #11949); corrects scope for ES2022 private property brand checks (#11953); and lands seven internal React Compiler fixes (#11940, #11943, #11946, #11950, #11951, #11952, #11957) plus a parser fix that allows no-default builds (#11956) and a docs entry on the untrusted input security scope (#11937).

Oxc release crates_v0.137.0, published on 2026-06-18, ships two new minifier passes (treeshake pure typed arrays and Set/Map array literals via #23469, and inline const values for read-only vars via #22593), a long-running incremental scoping refresh that retires the LiveUsageCollector collector entirely (#23197), a friendly parser error for adjacent JSX elements (#23378), a React Compiler bug fix for computed-key imports (#23586), and two breaking changes to the ESTree config API (#23573, #23574). The minifier pass list also gets a Proxy-aware object-introspection fix (#23483) and a new Map/WeakSet/WeakMap preservation rule for string arguments (#23470). v0.137 is the first crates release since v0.135 on 2026-06-08 and the second since Bun's native React Compiler integration landed on 2026-06-20.

PR #32504, merged into oven-sh/bun on June 20, 2026, turns the upstream React Compiler Rust port into a built-in `bun build` transform behind `--react-compiler` and `Bun.build({ reactCompiler: true })`. Bun ports the upstream `facebook/react` `compiler/crates/` workspace directly into a single `src/react_compiler/` crate (~62k LOC) instead of going through Babel, SWC, or Oxc, and on a large React codebase (around 860 components, 1400 memo slots) the compiler pass runs in 465 ms versus 9.15 s for the Babel plugin. The feature is experimental, off by default, and ships with `reactCompilerOutputMode` (client or ssr) and a `scripts/sync-react-compiler.sh` re-sync helper.

Astro 7.0.0-beta.6 (June 19, 2026) promotes the experimental route caching API to top-level stable, dropping the experimental.cache and experimental.routeRules flags in favor of a new top-level cache config and a cache helper. Beta.5 (June 18) made 'jsx' the default compressHTML mode, changing the rendered output of every site that relied on the legacy whitespace preservation. Beta.6 also pulls in @astrojs/markdown-satteri 0.3.1-beta.2.

pnpm 11.7.0 (June 15, 2026) ships four headline changes: a `--frozen-store` install mode for Nix stores, OCI layers, and other read-only mounts; delegation of dependency resolution to the pacquet Rust port (not just materialization); an opt-in `--batch` flag for `pnpm publish --recursive`; and a security fix that rejects path-traversal and reserved aliases (`.bin`, `.pnpm`, `node_modules`, `../../escape`) in lockfile-sourced dependencies.

Astro 7.0.0-beta.4 (June 15, 2026) flips the Sätteri Rust-based Markdown pipeline on by default, removes the experimental flag from advanced routing, the custom logger, and the new rendering engine, deletes the deprecated astro db/login/logout/link/init CLI commands, and folds the dev-server background mode added in alpha.2 into the default CLI.

Moonshot AI released Kimi K2.7-Code, a 1T-parameter MoE coding model with 32B activated and a 30% drop in thinking tokens versus K2.6. Xiaomi followed with MiMo Code, another open-weights coding model. Here is what is actually on the model card.

Oxc 0.135 integrates the React Compiler Rust port, marks AST nodes as #[non_exhaustive] (a breaking change for downstream Rust crates), adds two new template-escape AstBuilder methods, and brings dozens of parser strictness and codegen whitespace fixes.

The May 22 Nitro v3 beta ships build-time route handler tracing, a VFS-backed dynamic code cache for faster dev-server restarts, and Vercel queue support accessible in local development, alongside the security patches from the prior beta.

Vue 3.6 has entered beta with the completion of Vapor Mode, a virtual-DOM-free compilation path, and a major reactivity system overhaul based on alien-signals, promising significant performance gains.

WebKit, Google, and Mozilla just released JetStream 3, the first major overhaul of the benchmark suite since 2019. It drops microbenchmarks in favor of realistic workloads, rewrites WebAssembly scoring, and introduces Dart, Kotlin, and Rust compiled to Wasm.

TypeScript 6.0 is out, and the Microsoft team is clear: it's a bridge release. The real story is what comes next: TypeScript 7, written in Go and already available as a preview, promises a 10x speedup.

While ESLint v10 was wrestling with legacy cleanup, the Oxc project shipped a linter 100x faster, a formatter 30x faster than Prettier, and a parser that leaves SWC in the dust. Here's what the JavaScript oxidation compiler actually is.

The popular dependency and unused-code scanner for JavaScript and TypeScript gets a major overhaul, replacing its TypeScript backend with the Rust-based oxc-parser, and the results are dramatic.

The pure TypeScript NumPy implementation reaches a correctness milestone: random number generation now matches NumPy bit for bit, Float16 lands as a first-class dtype, and the package no longer needs per-runtime entry points.

Cheng Lou just released Pretext, a pure JavaScript library that measures and lays out multiline text without touching the DOM. Here's why that matters for virtualization, layout control, and AI agents that write UI code.

Three JavaScript runtimes. Three different philosophies. Independent benchmarks across HTTP throughput, cold starts, and async performance tell a clearer story than marketing ever could. Here's the brutally honest breakdown for developers choosing their next server-side JS platform.

Vue 3.5 arrived with no breaking changes and a set of internals improvements that should make any developer pay attention, 56% less memory usage, lazy hydration, and a stabilized reactive props API.