Cloudflare Acquires Deno and Ends Future Runtime Development
Cloudflare is acquiring Deno and will stop developing the Deno runtime after supporting it for one more year with updates. Creator Ryan Dahl stated the project did not solve big enough problems and got pulled into Node compatibility.
In short: Cloudflare is acquiring Deno and will stop developing the Deno runtime after supporting it for one more year with updates. Creator Ryan Dahl stated the project did not solve big enough problems and got pulled into Node compatibility.
Big changes are coming to the software development world as Cloudflare takes over a well-known project and plans to wind down its core runtime.
What happened, in plain words
On October 9th, 2026, it was announced that Cloudflare is acquiring Deno outright. Cloudflare plans to build upon celld, which is an open source version of a pattern from Cloudflare Workers. While the Deno runtime will receive bug fixes and security updates through monthly releases for another year, Cloudflare will stop developing it after that time, though it will stay open source. Ryan Dahl, who created both Deno and Node.js, explained in a comment that the project was pulled into the gravity well of Node compatibility and ultimately failed to solve big problems.
Key points
- Cloudflare acquisition: Cloudflare is acquiring Deno outright to build on celld and support self-hosting for apps using the Workers programming model.
- Runtime support timeline: Cloudflare will support the Deno runtime for one more year with monthly bug fixes and security updates before ending development.
- Creator reasoning: Ryan Dahl noted that Deno became too focused on behaving like Node.js instead of solving big problems and creating new abstractions.
- Permissions system history: Deno featured a permissions system to restrict file and network access, while Node.js later added a similar model in version 20.0.0 and stable version 22.13.0.
Terms explained
- Open source — Software where the code is publicly shared so anyone can view, use, and help improve it. Example: A recipe that is published online so any baker in the world can cook it and suggest improvements.
- API — A set of rules that lets different software programs talk to each other and share information. Example: A restaurant menu that tells you what you can order and how to ask the kitchen for it.
- Runtime — The environment or program that actually executes computer code on a machine. Example: A media player application that takes a digital video file and actually plays the moving pictures on your screen.
Why it matters
Developers who rely on the Deno runtime will need to plan for changes since official development will end after a year, though the open source project can still be picked up by others.
What we still don't know
The source notes future development by Cloudflare stops after one year and only mentions that others are welcome to continue developing Deno as an open source project.
Based on reporting from Simon Willison. This is an independent explainer, written in our own words with AI assistance; Simon Willison has not reviewed or endorsed it. Read the original for the full details.