What’s New in Deno 1.26? Key Features, Node.js Compatibility, and Performance Boosts

Deno 1.26 was officially released on September 29.

According to the release notes, the update adds several previously unsupported Node.js compatibility layer APIs.

The compatibility layer test suite has been updated to align with Node.js v18.8.0, preparing for Node.js 18 LTS next month.

Deno 1.26 also updates the Node.js character stream implementation to use the [email protected] NPM module, introducing new APIs such as Writable.toWeb() and Readable.toWeb() for converting Node.js streams to Web streams, and improves fs.ReadStream and fs.WriteStream compatibility.

Developers can upgrade with the following command: deno upgrade Major updates include:

Fixes related to NPM specifiers; NPM module support remains experimental and requires the –unstable flag.

Fixes false hanging errors on Windows; Deno.serve() provides a fast small HTTP server.

Adds CacheWeb API support for caching request/response objects, useful for dynamic responses.

New permission flag –allow-sys protects access to APIs that expose operating system information.

Bundled TypeScript 4.8.

The Deno team reports ongoing performance improvements aimed at reducing latency and processing overhead.

Developer experience enhancements include a comprehensive overhaul of search on deno.land, improving symbol lookup across built-in APIs, the standard library, and third‑party modules, as well as automatic linking of symbols in documentation.