preferably is an accessible template for pkgdown documentation websites. It uses a light and a dark theme and utilizes the prefers-color-scheme CSS variable to automatically serve either of the two based on users’ operating system setting, or allowing them to manually toggle between them.

Besides offering light and dark mode, I spent some time making the overall reading experience of ‘pkgdown’ documentations just a bit nicer, by using richer fonts, adopting a better color scheme for codes, etc.

Please let me know if you happen to use my template in your project. I’d like to keep a list of websites that are using ‘preferably’, see here: In the Wild!


install.packages("devtools"); library(devtools)


After the package is available on CRAN, you can install it like any other R package.


After the successful installation, if you already have your pkgdown setup ready, you only need to specify the template parameter as follow. Then, as before, you can build your site using build_site() and deploy it manually using deploy_on_branch().

  package: preferably

⚠️ Keep in mind that you should NOT use default_assets: false when you change the default template. ‘preferably’ relies on some of the ‘pkgdown’ assets and templates.


In the case that you are using CI systems to build and deploy your website, you need to make sure that ‘preferably’ is available on the environment. For GitHub Action, add the following line to the “Install dependencies” section of your .github/workflows/pkgdown.yaml file:

- name: Install dependencies
  run: |
    # ⚠️ leave other commands intact, 
    # and add the following command to the end of the list 👇🏼
    remotes::install_github("amirmasoudabdol/preferably", type = "source")

If you are using Travis-CI, add the following line to your .travis.yml file:

  - amirmasoudabdol/preferably


In addition of pkgdown customization, Preferably offers a few more options as listed here.

Custom Analytic

Preferably allows for adding a custom analytics (in addition to ganalytics) to your website via the canalytic option.

  package: preferably

Setting these command will generate the following line in the HTML:

<script async defer data-domain="" src=""></script>

In case this setting does not satisfy your need or you have a better idea on how to implement this, please reach out on GitHub.

Manual Light/Dark Toggle

In addition to the automatic color scheme switching, you can add a switch to the menu bar, e.g, , to allow for manual selection between light and dark themes. This can be done by setting the toggle option to manual.

  package: preferably
    toggle: manual

Unfortunately, it is not possible to have both the automatic and manual mode at the same time. There is an user experience issue here, and it is almost impossible to deliver a seamless experience without involving the server-side, here, and here. So, you need to choose whether you like to give your users a manual toggle, or let your website adapts to their system preference.

⚠️ In order to remove the toggle button, remove the toggle parameters.



The goal of preferably is to improve the accessibility and readability of your documentation websites.

Future Plan

My main focus is to keep preferably light and compatible with pkgdown. Besides, I have a short list of features that I would like to add to template files, and pkgdown package. For those, I prefer to prepare a few pull requests and add them to pkgdown instead of diverging the preferably from its core. Let’s see when I get to them! Here is a few:

  • Adding support for responsive text sizing
  • Improving the appearance of argument lists
  • Minimizing the size of default pkgdown templates and assets


If you found any bugs, or have any suggestions, please feel free to reach out to me, either by opening an issue or a pull request, or dropping an email.


You can support my projects by either sponsoring me on GitHub or buying me a few cups of coffee!