Tune vim startup time

My vim has been quite slow on startup and I really want to make it faster, otherwise it would be a pain to use vim, which should not be the case!

There are multiple ways to profile the startup time of vim:

• The native profiler vim provides, see this stackoverflow question
• vim-startuptime-benchmark
• vim-plugins-profile

The tool I chose to use is: vim-plugins-profile, which I found is much easier to use. It provides scripts in different languages for use. The bash script seems requiring the R to be installed. The one I chose to use is the python script, which is really use to use. Since I use neovim, here is the command I use:

python vim-plugins-profile.py nvim

The scripts gives you the top ten most time-consuming plugins. And that’s what you should look into to improve the startup time. For me, the following plugins took long time to load:

• vimwiki
• vim-prettier

Since I don’t use them on all scenarios, the strategy I use is to lazy load them, i.e. only load them when needed. Fortunately the plugin manager vim-plug has already provided the on-demand loading mechanism for this. Checkout the Plug options for the on-demand loading. There are two different options:

• on on On-demand loading: Commands or <Plug>-mappings
• for On-demand loading: File types

Since vim-prettier is primarily for front-end development and its author actually provides an example of how to lazy load the plugin, which is exactly what I need (not sure why I didn’t use it at the beginning.):

Plug 'prettier/vim-prettier', {
  \ 'do': 'yarn install',
  \ 'for': ['javascript', 'typescript', 'css', 'less', 'scss', 'json', 'graphql', 'markdown', 'vue', 'yaml', 'html'] }

For vim-wiki, as it’s only used for editing my personal wiki, I don’t need it to be loaded all the time. To lazy load it, there are two different options:

• to enable it for some particular file types - for, which is how it’s done for vim-prettier.
• to enable it for some particular command, which is the on command in vim-plug

As I don’t need to enable vimwiki most of the time, I decided to load it via a command. i.e. to enable it, :VimwikiUISelect has to be typed.

Using this technique, I also converted couple of the other slow plugins to be loaded on-demand. After doing these, now my vim starts super-fast! And I am very happy with the result!