Preflight In Ruby

The PDF spec is a beast. Amongst a long list of features it allows transparencies, embedding of flash, video and javascript, content encryption and multiple colour spaces.

Such features have their place, but sometimes you just need to say no. Standards like PDF/A and PDF/X are subsets of the full PDF spec that target particular use cases like archiving or printing.

To check a given PDF conforms to a required standard you run a preflight check. There are expensive programs that can preflight, but they’re ….. expensive, and generally hard to script.

I recently released the preflight rubygem for performing preflight checks from ruby. It’s not as full featured as the commercial options, but it’s free and may solve 80% of your problem.

Start by installing the gem

    gem install preflight

To check a file passes a PDF/X-1a preflight it’s just three lines.

    require 'preflight'

    preflight =

    puts preflight.check("somefile.pdf").inspect

If you need more control over the profile, you can build your own profile.

    require "preflight"

    class MyPreflight
      include Preflight::Profile

      rule Preflight::Rules::MaxVersion, 1.4
      rule Preflight::Rules::DocumentId
      rule Preflight::Rules::OnlyEmbeddedFonts
      rule Preflight::Rules::MinPpi, 300

    preflight =

    puts preflight.check("somefile.pdf").inspect

For a list of available rules, check out the classes in the Preflight::Rules namespace - each class has documentation describing how to use it in a profile.

If the provided rules don’t cover everything you need, you can also write your own.

For more details and examples, check out project on github.