Yazi image preview shows up super slow with kitty + tmux

[onion108]

What system are you running Yazi on?

Linux Wayland

What terminal are you running Yazi in?

kitty v0.42.2

yazi --debug output

Yazi
    Version: 25.5.31 (Arch Linux 2025-07-23)
    Debug  : false
    Triple : x86_64-unknown-linux-gnu (linux-x86_64)
    Rustc  : 1.88.0 (6b00bc38 2025-06-23)

Ya
    Version: 25.5.31 (Arch Linux 2025-07-23)

Emulator
    TERM                : Some("tmux-256color")
    TERM_PROGRAM        : Some("tmux")
    TERM_PROGRAM_VERSION: Some("3.5a")
    Brand.from_env      : Some(Kitty)
    Emulator.detect     : Emulator { kind: Left(Kitty), light: false, csi_16t: (11, 24), force_16t: false }

Adapter
    Adapter.matches    : Kgp
    Dimension.available: Dimension { rows: 39, columns: 172, width: 1892, height: 936 }

Desktop
    XDG_SESSION_TYPE           : Some("wayland")
    WAYLAND_DISPLAY            : Some("wayland-1")
    DISPLAY                    : Some(":1")
    SWAYSOCK                   : None
    HYPRLAND_INSTANCE_SIGNATURE: Some("4e242d086e20b32951fdc0ebcbfb4d41b5be8dcc_1755865753_1295101128")
    WAYFIRE_SOCKET             : None

SSH
    shared.in_ssh_connection: false

WSL
    WSL: false

Variables
    SHELL           : Some("/bin/zsh")
    EDITOR          : Some("nvim")
    VISUAL          : None
    YAZI_FILE_ONE   : None
    YAZI_CONFIG_HOME: None
    YAZI_ZOXIDE_OPTS: None
    FZF_DEFAULT_OPTS: None

Text Opener
    default     : Some(OpenerRule { run: "${EDITOR:-vi} \"$@\"", block: true, orphan: false, desc: "$EDITOR", for: None, spread: true })
    block-create: Some(OpenerRule { run: "${EDITOR:-vi} \"$@\"", block: true, orphan: false, desc: "$EDITOR", for: None, spread: true })
    block-rename: Some(OpenerRule { run: "${EDITOR:-vi} \"$@\"", block: true, orphan: false, desc: "$EDITOR", for: None, spread: true })

Multiplexers
    TMUX               : true
    tmux version       : tmux 3.5a
    tmux build flags   : enable-sixel=Unknown
    ZELLIJ_SESSION_NAME: None
    Zellij version     : 0.43.1

Dependencies
    file          : 5.46
    ueberzugpp    : No such file or directory (os error 2)
    ffmpeg/ffprobe: 7.1.1 / 7.1.1
    pdftoppm      : 25.08.0
    magick        : 7.1.2-1
    fzf           : 0.65.1
    fd/fdfind     : 10.2.0 / No such file or directory (os error 2)
    rg            : 14.1.1
    chafa         : No such file or directory (os error 2)
    zoxide        : No such file or directory (os error 2)
    7zz/7z        : No such file or directory (os error 2) / 25.01
    resvg         : No such file or directory (os error 2)
    jq            : 1.8.1

Clipboard
    wl-copy/paste: 2.2.1 / 2.2.1
    xclip        : No such file or directory (os error 2)
    xsel         : No such file or directory (os error 2)

Routine
    `file -bL --mime-type`: text/plain


See https://yazi-rs.github.io/docs/plugins/overview#debugging on how to enable logging or debug runtime errors.

Describe the question

The image shows up in yazi only after about 15-20 seconds. It also super slow without tmux somehow (but sometimes not that slow), and for whatever reason if you attempt to move the window you can see it actually is displayed but somehow not drawn. But there no problem with timg.

yazi_example.mp4

I'm wondering what's different between yazi and timg rendering images.

Anything else?

No response

Checklist

• I have read all the documentation
• I have searched the existing discussions/issues

[sxyazi]

That's weird, I haven't seen this issue before, nor can I reproduce it on my side, but here are some checks I can think of that may help:

• Can the issue be reproduced in the latest nightly version of Yazi?
• Does the issue still if both kitty and tmux are started with their default configurations?
• Does the problem occur in other terminals (such as WezTerm, Ghostty), with or without tmux?
• If you launch kitty from the command line, does kitty output any errors when previewing images?

[onion108]

Tried in order and here are results.

Can the issue be reproduced in the latest nightly version of Yazi?

No. (as for c27ef58116794de7f559bca74e60e6e13ae92051; the following tests are all using this version from now; as for kitty, my kitty is always nightly)

Does the issue still if both kitty and tmux are started with their default configurations?

No. The image still shows up super slow.

Does the problem occur in other terminals (such as WezTerm, Ghostty), with or without tmux?

	Wezterm	Ghostty
without tmux	no problem	no problem
with tmux	no problem	no problem

Great. It might probably be a kitty problem then.

If you launch kitty from the command line, does kitty output any errors when previewing images?

Without tmux, no.
With tmux, I got this:

[52.391] Application escape mode is not supported, the extended keyboard protocol should be used instead
[52.391] Application escape mode is not supported, the extended keyboard protocol should be used instead
[52.391] Application escape mode is not supported, the extended keyboard protocol should be used instead

Doesn't seem much related to the problem.

New discoveries during tests:

1. Picture shows up immediately as I switch to another workspace and back. (maybe some refreshing issue?)
2. Without wf-recorder kitty (without tmux) works normal. But it behaves like in tmux when I trying to record that (so you can see I was surprised when trying to use without tmux with screen recording)

[onion108]

Tried in order and here are results.

Can the issue be reproduced in the latest nightly version of Yazi?

No. (as for c27ef58116794de7f559bca74e60e6e13ae92051; the following tests are all using this version from now; as for kitty, my kitty is always nightly)

Does the issue still if both kitty and tmux are started with their default configurations?

No. The image still shows up super slow.

Does the problem occur in other terminals (such as WezTerm, Ghostty), with or without tmux?

Wezterm Ghostty
without tmux no problem no problem
with tmux no problem no problem

Great. It might probably be a kitty problem then.

If you launch kitty from the command line, does kitty output any errors when previewing images?

Without tmux, no. With tmux, I got this:

[52.391] Application escape mode is not supported, the extended keyboard protocol should be used instead
[52.391] Application escape mode is not supported, the extended keyboard protocol should be used instead
[52.391] Application escape mode is not supported, the extended keyboard protocol should be used instead

Doesn't seem much related to the problem.

New discoveries during tests:

1. Picture shows up immediately as I switch to another workspace and back. (maybe some refreshing issue?)

2. Without `wf-recorder` kitty (without tmux) works normal. But it behaves like in tmux when I trying to record that (so you can see I was surprised when trying to use without tmux with screen recording)

It's probably a kitty problem. I'm going to report that to kitty's repository as well.

[sxyazi]

Thank you for your update!

as for kitty, my kitty is always nightly

Have you tried the stable version of kitty to see if the issue still?

It might probably be a kitty problem then

For Ghostty, Yazi uses the same image protocol as kitty - Kitty unicode placeholders, so if Ghostty can preview images, then that should rule out the problem with the protocol implementation within Yazi.

For WezTerm, Yazi uses the Inline images protocol, since WezTerm also works here, this further rules out issues with Yazi decoding the image and sending it to the terminal.

Doesn't seem much related to the problem

Yeah, that log is related to the keyboard protocol and has nothing to do with the image, just ignore it.

Picture shows up immediately as I switch to another workspace and back. (maybe some refreshing issue?)

If the image shows up after a while, it means the image was correctly sent to kitty and kitty can understand it, since Yazi only does that once with no delay, but kitty just can't render the image in time.

I feel this could be an issue specific to the kitty + Wayland (compositor) combination, or possibly a graphics driver issue. Maybe it's worth trying kitty + X11 combination to see if we can further rule the issue out

[onion108]

Thank you for your update!

as for kitty, my kitty is always nightly

Have you tried the stable version of kitty to see if the issue still?

It might probably be a kitty problem then

For Ghostty, Yazi uses the same image protocol as kitty - Kitty unicode placeholders, so if Ghostty can preview images, then that should rule out the problem with the protocol implementation within Yazi.

For WezTerm, Yazi uses the Inline images protocol, since WezTerm also works here, this further rules out issues with Yazi decoding the image and sending it to the terminal.

Doesn't seem much related to the problem

Yeah, that log is related to the keyboard protocol and has nothing to do with the image, just ignore it.

Picture shows up immediately as I switch to another workspace and back. (maybe some refreshing issue?)

If the image shows up after a while, it means the image was correctly sent to kitty and kitty can understand it, since Yazi only does that once with no delay, but kitty just can't render the image in time.

I feel this could be an issue specific to the kitty + Wayland (compositor) combination, or possibly a graphics driver issue. Maybe it's worth trying kitty + X11 combination to see if we can further rule the issue out

Nothing to do with kitty. kitty refreshes images when the program
running in it tells it to. Report the issue to yazi. Or if I had to
guess remove the open tmux line in your reproducer.

Reported to kitty and kitty's author says it's not kitty's problem (?)
Originally posted by @kovidgoyal in #8924

I may try X11 later and reply if there's anything different!

[onion108]

Thank you for your update!

as for kitty, my kitty is always nightly

Have you tried the stable version of kitty to see if the issue still?

It might probably be a kitty problem then

For Ghostty, Yazi uses the same image protocol as kitty - Kitty unicode placeholders, so if Ghostty can preview images, then that should rule out the problem with the protocol implementation within Yazi.

For WezTerm, Yazi uses the Inline images protocol, since WezTerm also works here, this further rules out issues with Yazi decoding the image and sending it to the terminal.

Doesn't seem much related to the problem

Yeah, that log is related to the keyboard protocol and has nothing to do with the image, just ignore it.

Picture shows up immediately as I switch to another workspace and back. (maybe some refreshing issue?)

If the image shows up after a while, it means the image was correctly sent to kitty and kitty can understand it, since Yazi only does that once with no delay, but kitty just can't render the image in time.

I feel this could be an issue specific to the kitty + Wayland (compositor) combination, or possibly a graphics driver issue. Maybe it's worth trying kitty + X11 combination to see if we can further rule the issue out

quickly tested under X11 and the issue still exists though. Gonna reboot because my sessions are in a mess now.

[onion108]

Thank you for your update!

as for kitty, my kitty is always nightly

Have you tried the stable version of kitty to see if the issue still?

It might probably be a kitty problem then

For Ghostty, Yazi uses the same image protocol as kitty - Kitty unicode placeholders, so if Ghostty can preview images, then that should rule out the problem with the protocol implementation within Yazi.

For WezTerm, Yazi uses the Inline images protocol, since WezTerm also works here, this further rules out issues with Yazi decoding the image and sending it to the terminal.

Doesn't seem much related to the problem

Yeah, that log is related to the keyboard protocol and has nothing to do with the image, just ignore it.

Picture shows up immediately as I switch to another workspace and back. (maybe some refreshing issue?)

If the image shows up after a while, it means the image was correctly sent to kitty and kitty can understand it, since Yazi only does that once with no delay, but kitty just can't render the image in time.

I feel this could be an issue specific to the kitty + Wayland (compositor) combination, or possibly a graphics driver issue. Maybe it's worth trying kitty + X11 combination to see if we can further rule the issue out

the stable version works! seems really just a nightly problem.