Existing benchmarks measure solve rate and token output/cost, but don't punish excess code, which makes a codebase harder to work with in the long term. I wanted to measure this since it matters most for long-term projects.Method: it takes the patches that benchmarks already publish (DeepSWE, SWE-bench Verified, SWE-bench Live) and counts "coding units": syntax elements like statements, calls, names and literals. I didn't use lines of code, so cramming code isn't rewarded. Deleted code is subtracted, so it measures net units.GPT-6 and Claude 5.5 have no public patches yet, so I ran them myself on 3–10 tasks on my own subscriptions (shown as faded circles, not ranked).Any feedback or model contributions are welcome, especially public patch exports for newer models.GitHub: https://github.com/La5u/ParsimonyNot affiliated with any of the benchmarks.
Show HN: Parsimony – an open-source benchmark for how much code AI models add
An open-source benchmark of how much code AI models add.

Key takeaways
Parsimony is an open-source benchmark that measures how much code AI models add, focusing on code efficiency.
- It counts coding units like statements and calls, not lines of code.
- Models are ranked by the net units of code they add.
- Users can input their own code-size numbers to generate charts and tables.
Summarised automatically by AI from the original article by Hacker News. AI can make mistakes, so check the original for details.
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