// HACKER NEWS — CYBERSECURITY
Bun 1.4
Bun is the complete toolkit for building and testing full-stack JavaScript and TypeScript applications. If you're new to Bun, you can learn more from the Bun 1.0 blog post.
Bun 1.4 adds +1,517 tests from the Node.js test suite - our biggest jump in Node.js compatibility since Bun 1.0. Bun v1.4 also fixes over 2,900 issues. It reduces idle CPU usage by 5x, reduces memory usage by up to 35%, and starts 50% faster on Linux. It adds Bun.Image, Bun.WebView, Bun.markdown, Bun.cron(), Bun.Terminal, bun run --parallel, bun test --parallel, bun audit fix, bun dedupe, and bun prune. And it rewrites Bun from Zig to Rust.
This post covers everything we've shipped since Bun 1.3.0 (with new to Bun v1.4 tagged).
Bun is designed to be a drop-in replacement for Node.js. We've added +1,517 tests from the Node.js test suite to run on every commit of Bun.
node:http, node:fs, node:cluster, node:timers, node:zlib, node:vm, and node:stream pass 97% of Node's own tests; node:quic 99%; node:events, node:trace_events, and node:sqlite 100%.
Bun is not 100% compatible with Node.js yet. In practice, much of the existing JavaScript ecosystem just works. You can more closely track Bun's Node.js test suite progress here.
Playwright now runs on Bun: drive a browser with connectOverCDP(), run your suite with playwright test and a playwright.config.ts, open --ui, and launch Chromium on Windows.
bun --bun next build works on Next.js 16.3 with Turbopack and the React Compiler.
vitest runs under Bun, including --coverage, with the threads and forks pools.
OpenTelemetry's http and fs instrumentation export spans, and shimmer and require-in-the-middle patch bundled code.