The Ship of Theseus
Track how much of your codebase's original code still survives over time.
What is the Ship of Theseus Code Visualizer? Ship of Theseus is an open-source tool that analyzes Git histories to show how quickly software evolves and how much of its original foundation remains.
Insights
How much foundation remains?
--
of current codebase is foundation code
How old is the code?
--
Repository birth year
--
Earliest code still here
When was the biggest rewrite?
--
Biggest rewrite date
Which year's code survives most?
--
Year with most surviving code
What's the average code age?
--
Average code age
Request a repository
Don't see your favourite open source repository? Drop the URL below.
Submitted via Web3Forms. Just the URL, nothing else.
Ancient Code Fragments
Click the file path below to view on GitHub
Loading...
The oldest line ever written in this repo's history, even if deleted long ago.
Loading...
The oldest line that is still alive in the codebase today.
Where did this all come from?
Built by Asif Sayyed, a data scientist wondering if the Ship of Theseus paradox applies to codebases, if you replace every line over time, is it still the same repo? This tool tracks how much original code survives as projects evolve.
Data Scientist who also happens to read far too much philosophy
Frequently Asked Questions
What is the Ship of Theseus Code Visualizer?
The Ship of Theseus Code Visualizer is an open-source tool that analyzes Git repository histories to show how much of a codebase's original code still survives over time.
Why is codebase entropy important?
Codebase entropy shows how quickly software is changing. A stable architecture holds onto old code, while frequent rewrites result in high entropy and rapid loss of original lines.
How does the visualizer calculate codebase survival?
It uses Git history to track each line of code from its creation commit. By comparing historical snapshots, it calculates the exact percentage of original lines still present today.
What programming languages does the visualizer support?
The Ship of Theseus tool analyzes Git commits directly, meaning it is entirely language-agnostic. It works out-of-the-box with Python, JavaScript, HTML, CSS, C++, Rust, and any other text-based language.
Is this tool free to use?
Yes, the Ship of Theseus Code Visualizer is completely free and open-source. You can access the source code on GitHub and use it to analyze your own repositories.
How do I interpret the visualizer graphs?
The chronological mode shows code loss over time, while the identity mode groups remaining code by its original commit. A steep drop indicates major rewrites, while a flat line suggests stable architecture.
What is a 'fossil' in this context?
A fossil is a specific line of code that has survived unchanged over a long period. We track two types: the Historical Fossil (from the repository's origin), and the Living Fossil (the absolute oldest line of code still present in the codebase today).