polydiff

One git config. Every file type gets a real diff.

Git is excellent at diffing text/code, and useless at diffing anything else. Run git diff on a changed PNG, PDF, or XLSX file and you get:

Binary files a/logo.png and b/logo.png differ

That's it. No visual, no summary, nothing actionable.

polydiff fixes that in one command.

Quick Start

pip install polydiff

# In your git repo:
polydiff install

# Now git diff works on binary files:
git diff  # Shows real visual/cell/text diffs for images, PDFs, Excel files

# Or use standalone (no git required):
polydiff diff old.png new.png
polydiff diff old.pdf new.pdf
polydiff diff old.xlsx new.xlsx

What It Does

Format	What you get
Images (PNG, JPG, WebP, BMP)	Visual side-by-side diff with changed regions highlighted, similarity score
PDFs	Per-page visual diff + text-layer diff, page additions/removals detected
XLSX	Cell-level changes, rows/columns added/removed, formula changes, sheet changes

Delegation to Existing Tools

polydiff doesn't reinvent wheels that already roll well:

• Jupyter notebooks (.ipynb) → delegates to nbdime
• CSV/TSV → delegates to daff

When you run polydiff install, it detects these tools and wires them in automatically.

Plugin System

Support new formats by installing plugins:

pip install polydiff-plugin-cad  # hypothetical community plugin

Or write your own plugin in 30 minutes.

Commands

Command	Purpose
polydiff diff <a> <b>	Compare two files directly
polydiff install	Auto-configure git integration
polydiff plugins list	Show installed plugins
polydiff doctor	Check environment health

License

MIT — free for personal and commercial use.