Zellij vs tmux for AI Agents (2026)

tmux is nineteen years old and it shows, in both directions. It is everywhere, it is stable, it is on every server you will ever touch. It also has a config file that reads like a dialect and a discoverability story of "read the man page."

Zellij is the Rust challenger that ships with the keybindings printed on screen. Since 2021 it has matured into something with a stable feature set, and two of its features are directly relevant to running coding agents.

Having run both under agent workloads, here is the honest split.

The single biggest difference

Zellij tells you what you can do. tmux does not.

Zellij's default UI has a status bar listing the available actions for the current mode, updating live. New pane, new tab, resize, detach — all visible, all the time. You do not memorize a prefix key and then a second key.

That sounds like a beginner concern. It is not, quite. The real effect is that you use more of the tool. Most long-time tmux users I know use maybe eight commands, because those are the eight they learned in their first week and there was never a moment where the interface suggested a ninth. Zellij surfaces the rest.

The cost is screen space — a permanent status bar and pane borders. On a 13-inch laptop that is a real fraction of your terminal, and it is why some people bounce off it immediately. You can turn it off, at which point you have removed the main reason to prefer it.

Session resurrection is the feature that matters for agents

This is Zellij's actual differentiator and it is worth understanding precisely.

Zellij can bring back a closed session with its full pane structure and the commands that were running, including across a reboot. tmux can do session persistence, but it takes tmux-resurrect plus tmux-continuum plus configuration, and restoring running processes is a best-effort thing you have to opt each command into.

For agent work this matters more than it used to. A workspace where pane one is an agent in ~/code/api, pane two is the dev server, and pane three is a log tail is a thing you rebuild several times a week. Zellij treats that arrangement as data.

The caveat: it restores the layout and commands, not the state inside them. Your agent comes back as a freshly started agent in the right directory, not mid-conversation with its context intact. Nothing can give you the latter — that is the agent's own session management, not the multiplexer's.

Floating panes solve a specific, real annoyance

Zellij's floating panes are first-class: Alt f toggles them, they persist, and a command left running in a hidden floating pane keeps running.

The use case that sold me: you are watching an agent work in a full-width pane and you need to run git status or check a log. In tmux you split, which reflows the agent's pane and makes its TUI redraw at a new width — sometimes badly, since a lot of agent TUIs handle resize by repainting the whole screen and eating your scroll position.

With a floating pane, the layout underneath does not move. You pop the float, run the thing, dismiss it, and the agent never noticed. On a terminal where you have carefully arranged three sessions, that is worth real money.

Where tmux still wins

Remote. This is not close. tmux is on every machine, or one apt install away, and it has lower baseline memory and CPU. Zellij is not lighter than tmux, and on a small VPS with several sessions that shows up. If your target is a $5 box, use tmux.

Ubiquity. You SSH into a client's server, a CI runner, a container. tmux is there. Zellij is a thing you have to install, and sometimes cannot.

Ecosystem. Two decades of plugins, and every terminal-adjacent tool has thought about tmux specifically. Zellij's plugin system is WASM-based and genuinely interesting, but the library is a fraction of the size.

Muscle memory. If prefix-c is wired into your hands, that is an asset. Zellij's defaults collide with common terminal and editor bindings — Ctrl-o, Ctrl-n, Ctrl-t — and its lock mode exists specifically because of this. You will spend a week remapping.

It is finished. tmux does not change under you. Zellij is at 0.4x and still moving; that is exciting for features and occasionally annoying for config stability.

Config, side by side

The same basic setup in both. tmux:

# ~/.tmux.conf
set -g mouse on
set -g base-index 1
set -g default-terminal "tmux-256color"
set -ga terminal-overrides ",*256col*:Tc"
set -g history-limit 50000
bind | split-window -h
bind - split-window -v

Zellij:

// ~/.config/zellij/config.kdl
theme "catppuccin-mocha"
default_shell "zsh"
pane_frames false
scroll_buffer_size 50000

keybinds {
    normal {
        bind "Alt f" { ToggleFloatingPanes; }
    }
}

KDL is more readable than tmux's command language, and it is also another format to learn. pane_frames false is the setting most people want early — it reclaims the borders while keeping the status bar.

scroll_buffer_size and history-limit are the ones to actually raise in both. Agent transcripts are long, and the default in each will lose the beginning of a session you wanted to re-read.

The layout thing, which is the real day-to-day difference

Zellij layouts are declarative files. This is the feature I would miss most going back.

// ~/.config/zellij/layouts/agent.kdl
layout {
    pane split_direction="vertical" {
        pane size="60%" {
            command "claude"
        }
        pane {
            pane
            pane command="npm" { args "run" "dev"; }
        }
    }
}

zellij --layout agent

One command, full workspace, agent already running. The tmux equivalent is a shell script of send-keys calls or a tmuxinator YAML file, and both work, and neither is as pleasant to write or read.

If you run multiple agents at once, having the arrangement be a file you edit rather than a script you debug is a meaningful upgrade — and it pairs well with git worktrees, since each worktree can get its own layout.

The problem both of them share

A multiplexer sits between your terminal and your agent, and both of those want the mouse and both want to own scrollback.

Mouse mode on in either one means your drag-to-select belongs to the multiplexer, not your terminal and not the agent's TUI. Scrollback becomes the multiplexer's copy mode, so your terminal's search, its selection behavior, and its click-to-open-path all stop applying to the thing you most want to search.

That is fine on a remote box, where there is no alternative. Locally it is worth asking whether you need it at all — a terminal with real session management gives you most of the layout benefit without inserting a layer. MOLTamp's ⌘P session manager searches every open session by name or folder and the tab lights up amber when a session needs input, which covers the two things people actually reach for tmux locally to get. The rest is in the 3.2 tab system.

Pick one

Zellij if you are local, you want layouts as files, and floating panes plus session resurrection sound like they solve problems you actually have. Budget a week for keybindings.

tmux if you SSH anywhere, if you run on constrained hardware, or if you already know it. Learning Zellij to replace a working tmux setup is a hobby, not an upgrade.

Neither, locally, if your terminal already does session management well and your work is on one machine. The layer costs you scrollback and mouse behavior, and locally you can often get the benefit without the cost.

MOLTamp is a skinnable terminal shell for agent work — up to 50 sessions, ⌘P search, per-session monitoring, and a community skin marketplace. Download it.