Neovim slow to launch and preview files due to treesitter?

[laurensdc]

Running stock Lazyvim. I disabled half the plugins, to no effect. Finally, I disabled treesitter and noticed a difference of almost 100ms startup time when opening a file nvim somefile.ts

Even then, when opening a file, I first see a black screen and only after that see the file contents popping up. It's visually noticable, that's how slow it is.

And still, even without treesitter, the Snacks picker file previews lag when scrolling to the list. They also take ~100ms to load.

I have installed the Helix editor and both opening files (with treesitter) and browsing the picker previews are very snappy and responsive.

I have the exact same issues on both my m-series macbook and my beefy Linux gaming PC. Same problem in iterm2, konsole, ghostty.

I've been troubleshooting and trying random optimization fixes for 10-15 hours in the last few weeks. It's very disappointing for an editor that is supposed to be "blazingly fast" to feel this sluggish, and to only get reasonable launch times disabling treesitter and basically all syntax highlighting.

What can I do? Is this a me problem or is neovim just... not that fast as people say?

My full config:
https://github.com/laurensdc/dotfiles/tree/main/.config/nvim

Edit: some more information from Lazy Profiler.

Launching a file with treesitter enabled:

   Home (H)   Install (I)   Update (U)   Sync (S)   Clean (X)   Check (C)   Log (L)   Restore (R)   Profile (P)   Debug (D)   Help (?) 

  Startuptime: 209.26ms

  Based on the actual CPU time of the Neovim process till UIEnter.
  This is more accurate than `nvim --startuptime`.
    LazyStart 14.13ms
    LazyDone  34.13ms (+20.01ms)
    UIEnter   209.26ms (+175.12ms)

  Profile

  You can press <C-s> to change sorting between chronological order & time taken.
  Press <C-f> to filter profiling entries that took more time than a given threshold

    ●  startuptime 209.26ms
    ●  BufReadPre 37.68ms
      ➜  nvim-lspconfig 37.63ms
        ★  mason.nvim 21.42ms
        ★  nvim-lspconfig/plugin/lspconfig.lua 0.3ms
        ★  mason-lspconfig.nvim 0.09ms
    ●  lazy.nvim 22.43ms
      ➜  spec 16.44ms
        ★  lazyvim.plugins 7.87ms
        ★  lazyvim.plugins.xtras 1.98ms
          ‒  lazyvim.plugins.extras.editor.snacks_picker 0.47ms
          ‒  lazyvim.plugins.extras.editor.navic 0.33ms
          ‒  lazyvim.plugins.extras.formatting.prettier 0.28ms
          ‒  lazyvim.plugins.extras.coding.mini-surround 0.18ms
          ‒  lazyvim.plugins.extras.editor.snacks_explorer 0.15ms
          ‒  lazyvim.plugins.extras.coding.blink 0.15ms
        ★  resolve plugins 0.77ms
        ★  plugins.colorscheme 0.51ms
        ★  lazyvim.plugins.lsp 0.35ms
        ★  plugins.extra-plugins 0.34ms
        ★  lazyvim.plugins.ui 0.3ms
        ★  lazyvim.plugins.colorscheme 0.29ms
        ★  lazyvim.plugins.linting 0.25ms
        ★  lazyvim.plugins.coding 0.25ms
        ★  lazyvim.plugins.editor 0.22ms
        ★  plugins.disabled 0.18ms
        ★  lazyvim.plugins.formatting 0.18ms
        ★  pkg 0.17ms
        ★  lazyvim.plugins.util 0.17ms
        ★  lazyvim.plugins.treesitter 0.16ms
        ★  plugins.plugin-settings 0.16ms
      ➜  module 3.38ms
      ➜  handlers 1.62ms
      ➜  state 0.26ms
      ➜  config 0.16ms
      ➜  install 0ms
    ●  VeryLazy 17.49ms
      ➜  lualine.nvim 10.12ms
        ★  nvim-navic 0.85ms
      ➜  which-key.nvim 0.89ms
        ★  which-key.nvim/plugin/which-key.lua 0.14ms
    ●  CmdlineEnter 13.01ms
      ➜  blink.cmp 12.99ms
        ★  blink.cmp/plugin/blink-cmp.lua 7.73ms
        ★  friendly-snippets 0.29ms
    ●  startup 12.59ms
      ➜  start 8.58ms
        ★  start  LazyVim 6.29ms
          ‒  colorscheme 5.41ms
            ●  koda.nvim 0.14ms
        ★  start  snacks.nvim 2.27ms
          ‒  snacks.nvim/plugin/snacks.lua 1.12ms
      ➜  rtp plugins 3.64ms
        ★  runtime/plugin/matchit.vim 0.9ms
        ★  runtime/plugin/netrwPlugin.vim 0.8ms
        ★  runtime/plugin/matchparen.vim 0.28ms
        ★  runtime/plugin/rplugin.vim 0.25ms
        ★  runtime/plugin/editorconfig.lua 0.22ms
        ★  runtime/plugin/shada.lua 0.2ms
        ★  runtime/plugin/net.lua 0.19ms
        ★  runtime/plugin/osc52.lua 0.18ms
        ★  runtime/plugin/man.lua 0.18ms
        ★  runtime/plugin/spellfile.lua 0.18ms
      ➜  runtime/filetype.lua 0.32ms
      ➜  init 0.02ms
        ★  init  lualine.nvim 0.01ms
        ★  init  conform.nvim 0ms
        ★  init  mini.icons 0ms
        ★  init  nvim-navic 0ms
      ➜  after 0.01ms
    ●  LazyFile 5.89ms
      ➜  nvim-treesitter 5.38ms
        ★  nvim-treesitter/plugin/filetypes.lua 2.4ms
        ★  nvim-treesitter/plugin/nvim-treesitter.lua 0.25ms
        ★  nvim-treesitter/plugin/query_predicates.lua 0.16ms
      ➜  nvim-lint 0.48ms
      ➜  nvim-lint 0.01ms

Launching the same file with treesitter disabled, nothing else modified, only adding this line in plugins/disabled.lua:
{ "nvim-treesitter/nvim-treesitter", enabled = false },

   Home (H)   Install (I)   Update (U)   Sync (S)   Clean (X)   Check (C)   Log (L)   Restore (R)   Profile (P)   Debug (D)   Help (?) 

  Startuptime: 76.17ms

  Based on the actual CPU time of the Neovim process till UIEnter.
  This is more accurate than `nvim --startuptime`.
    LazyStart 15.61ms
    LazyDone  36.96ms (+21.36ms)
    UIEnter   76.17ms (+39.21ms)

  Profile

  You can press <C-s> to change sorting between chronological order & time taken.
  Press <C-f> to filter profiling entries that took more time than a given threshold

    ●  startuptime 76.17ms
    ●  BufReadPre 31.7ms
      ➜  nvim-lspconfig 31.69ms
        ★  mason.nvim 19.2ms
        ★  nvim-lspconfig/plugin/lspconfig.lua 0.34ms
        ★  mason-lspconfig.nvim 0.1ms
    ●  lazy.nvim 21.72ms
      ➜  spec 16.32ms
        ★  lazyvim.plugins 8.28ms
        ★  lazyvim.plugins.xtras 1.91ms
          ‒  lazyvim.plugins.extras.editor.snacks_picker 0.46ms
          ‒  lazyvim.plugins.extras.coding.mini-surround 0.19ms
          ‒  lazyvim.plugins.extras.coding.blink 0.18ms
          ‒  lazyvim.plugins.extras.formatting.prettier 0.17ms
          ‒  lazyvim.plugins.extras.editor.navic 0.17ms
          ‒  lazyvim.plugins.extras.editor.snacks_explorer 0.14ms
        ★  resolve plugins 0.92ms
        ★  lazyvim.plugins.lsp 0.42ms
        ★  plugins.disabled 0.31ms
        ★  lazyvim.plugins.editor 0.26ms
        ★  lazyvim.plugins.treesitter 0.24ms
        ★  lazyvim.plugins.linting 0.24ms
        ★  pkg 0.22ms
        ★  lazyvim.plugins.ui 0.21ms
        ★  lazyvim.plugins.coding 0.2ms
        ★  plugins.colorscheme 0.2ms
        ★  lazyvim.plugins.util 0.19ms
        ★  lazyvim.plugins.colorscheme 0.18ms
        ★  lazyvim.plugins.formatting 0.18ms
        ★  plugins.extra-plugins 0.17ms
        ★  plugins.plugin-settings 0.15ms
      ➜  module 2.9ms
      ➜  handlers 1.56ms
      ➜  config 0.19ms
      ➜  state 0.11ms
      ➜  install 0.02ms
    ●  VeryLazy 15.54ms
      ➜  lualine.nvim 9.8ms
        ★  nvim-navic 0.82ms
      ➜  which-key.nvim 0.68ms
        ★  which-key.nvim/plugin/which-key.lua 0.14ms
    ●  startup 9.59ms
      ➜  start 6.25ms
        ★  start  LazyVim 4.82ms
          ‒  colorscheme 4.09ms
            ●  koda.nvim 0.12ms
        ★  start  snacks.nvim 1.42ms
          ‒  snacks.nvim/plugin/snacks.lua 0.67ms
      ➜  rtp plugins 3.11ms
        ★  runtime/plugin/matchit.vim 0.8ms
        ★  runtime/plugin/netrwPlugin.vim 0.6ms
        ★  runtime/plugin/matchparen.vim 0.27ms
        ★  runtime/plugin/rplugin.vim 0.24ms
        ★  runtime/plugin/editorconfig.lua 0.21ms
        ★  runtime/plugin/man.lua 0.2ms
        ★  runtime/plugin/net.lua 0.2ms
        ★  runtime/plugin/osc52.lua 0.18ms
        ★  runtime/plugin/spellfile.lua 0.17ms
        ★  runtime/plugin/shada.lua 0.16ms
      ➜  runtime/filetype.lua 0.18ms
      ➜  init 0.02ms
        ★  init  lualine.nvim 0.01ms
        ★  init  conform.nvim 0ms
        ★  init  nvim-navic 0ms
        ★  init  mini.icons 0ms
      ➜  after 0.01ms
    ●  CmdlineEnter 6.62ms
      ➜  blink.cmp 6.6ms
        ★  blink.cmp/plugin/blink-cmp.lua 2.75ms
        ★  friendly-snippets 0.33ms
    ●  LazyFile 0.49ms
      ➜  nvim-lint 0.46ms
      ➜  nvim-lint 0.01ms

Edit 2: I've updated treesitter-cli from latest version, updated all plugins to latest version, did TSUpdate, tried loading Treesitter more lazily, tried disabling Treesitter in Snacks preview window, etc.