I built a live diff monitor for the terminal in Rust

Antonin Nvh — Sun, 14 Jun 2026 20:29:10 +0000

I built a live diff monitor for the terminal in Rust

I often want to see what changes while a tool is running, not only after the fact.

git diff is great when you decide to inspect the current state. It is less convenient when a formatter, generator, script, or refactor is changing files and you want a live view beside your editor.

That is the workflow Livediff is built for.

GitHub: https://github.com/SoCkEt7/Livediff

Demo: https://socket7.github.io/Livediff/

What Livediff does

Livediff watches a directory and displays file changes in an interactive terminal UI.

cargo install livediff
livediff

You can point it at a specific folder:

livediff ./src

Or ignore noisy paths:

livediff ./src --ignore "*.tmp" --ignore "target/"

Why a terminal UI?

I wanted something that could stay open next to an editor or test runner.

A terminal UI fits that workflow well:

no context switch to a separate desktop app;
low resource usage;
fast startup;
works naturally over SSH or inside terminal-heavy setups;
easy to keep open while scripts run.

The core design

Livediff combines a few pieces:

filesystem notifications for real-time updates;
diff computation to show what changed;
ignore handling for .gitignore and custom patterns;
a Rust TUI built with ratatui and crossterm;
syntax highlighting for a more readable diff view.

The goal is not to replace Git.

The goal is to give you a live “what is changing right now?” pane while you work.

Where it helps

The tool is useful when you are:

tweaking a code generator;
editing templates that produce files elsewhere;
watching a refactor touch multiple files;
comparing formatter output while tuning configuration;
monitoring docs or config changes during a script run.

What I learned building it

The interesting part was not only computing diffs. It was making the interface quiet enough to leave open.

A watcher can become noisy quickly. The UI has to answer a simple question: what changed, and where should I look first?

That pushed the project toward:

smart filtering;
compact file lists;
readable visual hierarchy;
event-driven redraws instead of constant polling.

Try it

cargo install livediff
livediff

Repository: https://github.com/SoCkEt7/Livediff

Browser demo: https://socket7.github.io/Livediff/

If you work in terminal-heavy environments and often need to watch generated or changing files, I would like to know what workflow you would test it on first.

DEV Community: Antonin Nvh

I built a live diff monitor for the terminal in Rust

I built a live diff monitor for the terminal in Rust

What Livediff does

Why a terminal UI?

The core design

Where it helps

What I learned building it

Try it