Release Notes

tmux 3.6b

Latest

May 20, 2026

GitHub

Highlights

Bug Fix Release

Maintenance release for tmux 3.6 with additional stability fixes.

Changes

Bug fixes on top of 3.6a
Stability improvements

tmux 3.6a

December 5, 2025

GitHub

Highlights

Bug Fix Release

Stability and correctness fixes for tmux 3.6.

Changes

Fix a buffer overread and an infinite loop in format processing
Allow drag in alternate screen again
Fix y offset of the mouse when the status line is at the top
Fix horizontal mouse resizing when pane status lines are enabled
Allow characters to be combined in either order; add a missing skin tone

tmux 3.6

November 26, 2025

GitHub

Highlights

Scrollbars Support

New pane-scrollbars option enables visual scrollbars in panes for easier navigation through long output.

Mode 2031 Theme Support

Enhanced theming capabilities with Mode 2031 support for more consistent terminal colors.

Improved Format Operators

Boolean expressions, #? operator, and sorting for loop operators provide more powerful formatting options.

Pixel Size Queries

Ability to send pixel size queries for better integration with graphical terminal features.

Clipboard Support Querying

New capability to query clipboard support from terminals for improved copy/paste workflows.

State Reporting

Support for reporting cursor, mouse, paste, and focus state for enhanced terminal awareness.

Changes

New pane-scrollbars option (with -position and -style) for per-pane scrollbars
codepoint-widths option to override the width of individual Unicode codepoints
copy-mode-selection-style and copy-mode-position-style for copy mode
tiled-layout-max-columns to cap columns in the tiled layout
no-detach-on-destroy client option and a new selection-mode command
OSC 4 palette queries are now forwarded to applications
Prompt cursor colour/style options; COLORTERM used as an RGB hint

⚠️ Upgrade Notes

• Important: Restart tmux entirely after upgrading (kill all sessions)
• If you see "open terminal failed: not a terminal" when attaching, restart tmux completely
• The sixel library protocol has changed, requiring a full restart

tmux 3.5a

October 5, 2024

GitHub

Highlights

Bug Fix Release

Stability improvements and bug fixes for tmux 3.5.

Changes

Represent Shift correctly with extended keys; stop translating BSpace as Unicode
Revert to /bin/sh for #(), run-shell and if-shell (default-shell now only affects popups)
Fix grey colour without a number suffix in styles

tmux 3.5

September 27, 2024

GitHub

Highlights

Extended Keys Overhaul

Extended (CSI u) key support was revamped to match xterm, with a new extended-keys-format option.

Copy-Mode Hyperlinks

OSC 8 hyperlinks are shown in copy mode, with a copy_cursor_hyperlink format for the link under the cursor.

Mirrored Layouts

New mirrored main-horizontal and main-vertical layouts put the main pane at the bottom or right.

Changes

Default escape-time reduced to 10 milliseconds
New prefix-timeout option cancels a half-entered prefix
search_count and search_count_partial formats in copy mode
display-menu -M to always enable the mouse in a menu
New command-error hook and allow-set-title option

tmux 3.4

February 13, 2024

GitHub

Highlights

SIXEL Images

Basic SIXEL graphics support (build with --enable-sixel) lets panes display images.

Shell Prompt Marking

OSC 133 support marks shell prompts; jump between them with next-prompt and previous-prompt.

Styled Menus

menu-style and menu-border-style bring popup-style theming to menus.

Changes

OSC 8 hyperlink support
allow-passthrough gained an "all" state for invisible panes
send-keys -K, scroll-top/scroll-bottom, and capture-pane -T
message-line option to control where messages and prompts appear
pane_unseen_changes format for unseen output while in a mode