Node.js 26 Arrives: Temporal API On by Default, V8 14.6, and the End of Biannual Releases

Node.js 26 is the first major release under the project’s new annual cadence — and it ships with the change JavaScript developers have been waiting years for: the Temporal API enabled by default.

Temporal: no more flags

The --harmony-temporal flag is gone. Temporal is on. The API provides timezone-aware, immutable date and time primitives that make working with dates in JavaScript finally sane — no DST edge cases silently swallowing your logic, no UTC arithmetic that forgets about the user’s actual location, no millisecond timestamp arithmetic as a fallback for every real-world scheduling task.

Temporal has been a TC39 Stage 3 proposal for years. The flag-gated preview has been in Node since version 21. Making it default in Node 26 means it will hit LTS this October and start appearing in production Node deployments without any opt-in. If you’ve been waiting for permission to start using it, this is it.

V8 14.6 and Undici 8.0

Node 26 ships with V8 14.6, tracking the Chromium 134 lineage — a significant bump from Node 24. The engine update brings performance improvements to object property access patterns and better JIT hints for numeric code. Undici 8.0 replaces the previous built-in HTTP client; it improves connection pooling, adds native support for the Fetch API’s keepalive behavior, and tightens the spec-compliance of the built-in fetch() implementation.

Annual release cadence — a real change

Node.js has historically shipped two major versions per year on an even/odd cycle, with even-numbered versions promoted to Long Term Support. That model is retired. Starting with Node 26, the project ships one major version per year, every April, with LTS promotion each October.

This matters for planning. You now have a full year on a major version before the next one arrives, and a predictable October window to upgrade to a stable LTS. Node 26’s LTS promotion is set for October 2026.

The breaking change that will catch people

The --experimental-transform-types flag is removed in Node 26. This flag enabled runtime stripping of TypeScript syntax — including enums and namespaces — without a build step. Projects that relied on it (often via ts-node or similar tools in non-compiled environments) will need to either add a build step or migrate to esbuild/swc for TypeScript enum support.

Notably, TypeScript enums and namespaces are the specific constructs this affects. If your TypeScript codebase only uses type annotations, interfaces, and generic syntax — which tsc --strip-types or the new TypeScript flag-stripping mode handles natively — you are unaffected. The flag removal targets the transform layer, not the type-stripping layer.

Build requirements

The minimum GCC version for building Node.js from source is now 13.2. This was a non-issue for most managed environments but will affect teams building custom Node distributions or maintaining Linux packages on older toolchain versions. The release itself was delayed from its April 22 target to early May due to a reproducibility failure in macOS ARM release builds triggered by the Temporal subsystem — a good sign that the team takes build determinism seriously.

Node 26 is available now. LTS lands in October. Start updating your Docker base images.