Identikal

A no frills tiny gem that does one thing and only one thing. It compares two unencrypted PDF files and returns true if they are identical and false otherwise. PDF comparison is done in pure Ruby with the help of HexaPDF and PDF::Reader.

Add this line to your application's Gemfile:

gem 'identikal'

And then execute:

$ bundle

Or install it yourself as:

$ gem install identikal

Comparing two PDFs from command line can be done by running the below command:

$ identikal file_a.pdf file_b.pdf
true

Text Only

If you would like to compare only the "text" content of the PDFs add the -t flag:

$ identikal -t file_a.pdf file_c.pdf
false

Besides the command line tool Identikal can also be used in a Ruby application. Identikal supports the following compare_method:

• :all compare text along with formatting
• :text compare only text content

:all is the default comparison method.

Text with formatting

require 'identikal'

base_path = File.expand_path(File.join(__dir__) + '/pdfs')
pdf_a = File.join(base_path, 'report_a.pdf')
pdf_b = File.join(base_path, 'report_b.pdf')

if Identikal.files_same?(pdf_a, pdf_b)
  # some action when files are identical
else
  # another action when files are different
end

Text Only

require 'identikal'

base_path = File.expand_path(File.join(__dir__) + '/pdfs')
pdf_a = File.join(base_path, 'report_a.pdf')
pdf_b = File.join(base_path, 'report_b.pdf')

if Identikal.files_same?(pdf_a, pdf_b, compare_method: :text)
  # some action when files are identical
else
  # another action when files are different
end

The gem is available as open source under the terms of the MIT License.