pdf-diff-screenshots

What problem does it solve?

Reviewing visual changes to documentation built from Markdown sources is tedious and error-prone when done manually. This Skill eliminates the need to build before and after PDFs yourself, hunt for the right pages, and manually crop screenshots by automating the entire workflow from git analysis to side-by-side comparison images.

Core Features & Use Cases

• Parallel Worktree Builds: Spins up isolated git worktrees to build before and after diff PDFs simultaneously, ensuring clean state and fast turnaround.
• Semantic Page Targeting: Reads PDF text to locate the exact pages affected by the branch, avoiding wasteful pixel-diffing of unchanged pages.
• Intelligent Region Cropping: Crops screenshots to pertinent sections using semantic understanding of diff substitution units and content reflow, not just raw pixel differences.
• Use Case: A technical writer modifies a specification section and needs to show the reviewer exactly how the rendered PDF changed, including figure captions and surrounding context.

Quick Start

Use the pdf-diff-screenshots skill to generate focused before and after screenshot pairs for the changes introduced by the current git branch.