mmux vs Zellij

What is Zellij?

Zellij describes itself as "a terminal workspace with batteries included" [1]. It is an MIT-licensed multiplexer written in Rust with its own client and server, so sessions keep running when you detach and you attach to them again later. On top of tiled panes and tabs it offers floating, stacked and pinned panes, command panes that show an exit code and re-run on Enter, KDL layout files, a session manager with session resurrection, and a WebAssembly plugin system that also implements parts of its own interface [2].

Recent releases widened its reach. 0.43.0 added a built-in web client for opening sessions in a browser [3]. 0.44.0 (March 2026) brought native Windows support, terminal-to-terminal attach over HTTPS, read-only sharing tokens and a much larger automation CLI [4]. 0.45.0 (August 2026) added first-class nested sessions, the Kitty graphics protocol, OSC 133 shell integration, desktop notification forwarding and a mobile web UI [5]. The maintainers also run Zellij.online, a paid hosted sharing service with a free tier that is in closed beta, and state that Zellij itself stays free and open source [6].

Where Zellij is better

• Pane layouts. Zellij tiles, floats, stacks and pins panes across tabs, and a KDL layout file can describe a whole environment with commands and plugins [2] [7]. mmux shows one program at a time in its main pane.
• Extensibility. Third-party WebAssembly plugins can read pane scrollback, highlight text and drive the session through a permissioned API [4]. mmux has no plugin system.
• Browser and shared sessions. The built-in web client serves sessions over HTTPS with authentication, other terminals can attach over HTTPS, and read-only tokens let someone watch without typing [3] [4]. 0.45 adds a touch interface for phones [5]. mmux works only in a terminal, with a single-column layout for narrow screens such as SSH from a phone.
• Platforms and dependencies. Zellij ships prebuilt binaries for Linux, macOS on Intel and Apple Silicon, and Windows [8] [9], and needs nothing else. mmux needs tmux on your PATH, has no Windows build, and covers Intel Macs only through Homebrew or a source build.
• Terminal features. Sixel and Kitty graphics, jumping between shell prompts, copying a command together with its output, and opening scrollback in your $EDITOR [2] [5]. mmux copy is drag-select only; there is no keyboard copy mode yet.

Where mmux is better

• Built for agents. Agents, terminals and processes each get a sidebar section, and you start an agent from your configured list with one keypress. A busy agent shows a gray spinner, a finished one turns green, and one blocked on a question shows a yellow ?, so the colored rows are the ones that need you. Zellij panes have no notion of an agent's state.
• Conversations come back. After a quit, a crash or a restart to update, reopening the directory restores your agents, and Claude, Codex, Pi and Grok agents resume their conversation. Zellij resurrection restores the layout and the pane commands, which wait for Enter before they run again [10].
• Native git panel. Changes, branches and recent commits sit in the right column. You stage, commit (with an AI-suggested message), branch and push without another tool, and clicking a file shows its diff in the main pane.
• Worktrees as projects. w cuts a git worktree that opens as its own project box with its own agents, terminals, processes and git panel. Only one checkout of a repository runs a given process at a time, so every branch reuses the same dev server ports. M merges it back, and finished worktrees clean themselves up.
• Agents can drive it. Zellij's CLI controls panes [12]. mmux's CLI also knows agent states: mmux wait returns when an agent is done or needs input, mmux answer picks an option on its prompt, and mmux ask hands a prompt to a new agent and prints its reply.
• One session per directory. Running mmux in a project attaches to the session that already exists there. mmux attach lists running and recent sessions, and a workspace manifest puts several projects in one sidebar.

When to use which

Using Zellij and mmux together

If Zellij is already your terminal workspace, keep it and run mmux in one of its panes for the agent work.

1. In a Zellij pane, set up the project once and open mmux:

   cd ~/some/project
   mmux init
   mmux

2. Zellij's default config binds Ctrl b to its tmux mode [11], and mmux uses Ctrl-b as its leader in a focused pane. Press Ctrl g to lock Zellij while you work in mmux, and again to unlock it.
3. Closing the Zellij pane only detaches mmux. Its tmux session keeps running, and mmux attach from any shell brings it back.

Commands you used to start from a Zellij layout, such as a dev server, become processes in mmux.yaml:

processes:
  - name: Dev server
    cmd: npm
    args: ["run", "dev"]
    autostart: false