Running Arch Linux in your browser

A real Arch install with pacman, gcc and python, starting in seconds — how the 9p filesystem trick makes that possible, and what it cannot do.

6 min readUpdated 2026-08-06

Arch Linux is the most capable system in this catalog by a wide margin — a real distribution with a real package manager, a compiler and an interpreter, on a machine that starts in about the time it takes to read this sentence. Both of those facts need explaining, because they should not be compatible.

There is no disk image

Every other machine here boots from a disk image — a file of raw sectors. Arch does not have one. Instead it uses 9p, a network filesystem protocol from Plan 9 that the Linux kernel speaks natively. The guest mounts its root filesystem over 9p, and the emulator answers those requests by fetching individual files over HTTP.

The difference matters. A disk image forces a decision about size up front, and reading a file means reading whatever blocks happen to hold it. Over 9p the guest asks for /usr/bin/python and gets exactly that file. Nothing you never open is ever transferred.

And it does not boot

Booting Arch properly under emulation — firmware, bootloader, kernel, systemd bringing up services one by one — takes minutes. So this machine skips it. It restores a snapshot taken after a previous boot had already finished, resuming a machine that was mid-run when it was frozen. What you see is not a fast boot; it is the absence of one.

What you can do with it

  • A real bash shell with coreutils — the actual GNU tools, not busybox approximations.
  • Write and compile C with gcc, then run the binary.
  • Run Python scripts.
  • Explore a normal Linux filesystem hierarchy, with man pages.
  • Use pacman to inspect the package database.

What you cannot

Installing packages needs a working network, and the guest can only reach the internet through a WebSocket relay — which is off by default and not something to rely on. Treat pacman as a way to look at what is installed, not a way to install more.

Nothing survives a reload, either. Anything you want to keep should be copied out, or captured as an exported state file.

Expectations

It is a real Arch Linux and it is genuinely slow — you are running a JIT-compiled emulator inside a browser tab. Compiling a small C file takes seconds rather than milliseconds. That is the honest trade: a complete Linux userland, available instantly, at a fraction of native speed.