Read this in X minutes Liquid Filter Plugin (for Jekyll)

reading_time.rb

# Outputs the reading time

# Read this in “about 4 minutes”
# Put into your _plugins dir in your Jekyll site
# Usage: Read this in about {{ page.content | reading_time }}

module ReadingTimeFilter
	def reading_time( input )
		words_per_minute = 180

		words = input.split.size;
		minutes = ( words / words_per_minute ).floor
		minutes_label = minutes === 1 ? " minute" : " minutes"
		minutes > 0 ? "about #{minutes} #{minutes_label}" : "less than 1 minute"
	end
end

Liquid::Template.register_filter(ReadingTimeFilter)

Thank you, it works like a charm!

Works perfect. Cheers.

Very nice, thanks for providing this.

I've forked this script to remove the dependence on the surrounding text (i.e. "about...") and remove all the text, so it now returns only an integer. This should make it more useful for multi-language implementations. There's already plenty of capability in Liquid's conditionals to handle proper pluralization. Optionally, one could leverage the Jekyll "pluralize" plugin to assist with this.

This is a rather opinionated set of changes, so I've gone so far as to change the Filter name as well, to avoid confusion with your work. However, if you'd like to take on or collaborate on these changes, we can certainly come up with a reasonable fusion, or you may of course simply use them how you wish. Thanks again for this work.

A sample implementation of these edits is here.