Docker’s First Wasm Preview: Is WebAssembly the Next Container Revolution?

Although Docker has long been eclipsed by the Kubernetes ecosystem, the company is still surviving and even showing signs of a financial turnaround.

This week Docker unveiled the first technical preview of its WebAssembly (Wasm) support tools.

Wasm originally gained traction among browser developers for running web applications at near‑native speed, with code compiled from languages such as C, C++, and Rust executing safely in a sandbox. Today about 40 languages can target Wasm, and, similar to how Node.js brought JavaScript to the server, Wasm is now moving to the backend; Cloudflare already runs Wasm at the edge.

Venture capitalists are eager to back this potential, with recent funding rounds such as Cosmonic’s $8.5 million for a Wasm PaaS and Fermyon’s $20 million Series A. Docker aims to join this wave.

Docker emphasizes that the announcement is only a technical preview and may not become a final product. In the proposed design, Docker Engine will continue using the containerd runtime but will replace the runC component with the WasmEdge runtime.

According to Docker, WasmEdge promises faster startup times than Linux containers and produces significantly smaller, faster‑running binaries.

Docker founder Michael Irwin wrote, “We view Wasm as a complementary technology to Linux containers; developers can choose the best solution for their use case—or even combine both. As the community explores Wasm’s possibilities, we hope you’ll use familiar tools to make Wasm applications easier to develop, build, and run.”

Docker also joined the Bytecode Alliance as a voting member, supporting the nonprofit organization that governs WebAssembly and its ecosystem, including the WebAssembly System Interface.