Moire shows what changed.

curl -fsSL https://sherin.dev/moire/install.sh | bash

Side by side or unified.

Changed lines sit next to their new version, with the changed words marked.

Copy changes across.

Take a change from either side; saving keeps the file's own encoding and line endings.

Jump between changes

with the keyboard, or click a mark in the change map beside the scroll bar.

Paste or type.

No files needed: paste two snippets and the comparison updates as you type.

Compare folders.

Every file in both folders is compared by its contents; double-click one to see what changed.

Fast on big files.

Myers' algorithm in linear space, the idea behind git diff, off the main thread.