| Name | Lines of code | Maintainability | Test coverage |
| lib/image_optim/worker/pngcrush.rb | 43 | A 0 mins | A 100% |
| lib/image_optim/worker/pngout.rb | 35 | A 1 hr | B 81% |
| lib/image_optim/worker/pngquant.rb | 57 | A 0 mins | A 100% |
| lib/image_optim/worker/svgo.rb | 28 | A 0 mins | B 86% |