NaturalCodeBench
Models solve 402 Python and Java problems taken from real user queries to online coding services in 6 domains. Semi-automatically built tests check each solution.
Prompts come in Chinese and English versions. Labs report a total over both.
In the authors’ words
Large language models (LLMs) have manifested strong ability to generate codes for productive activities. However, current benchmarks for code synthesis, such as HumanEval, MBPP, and DS-1000, are predominantly oriented towards introductory tasks on algorithm and data science, insufficiently satisfying challenging requirements prevalent in real-world coding. To fill this gap, we propose NaturalCodeBench (NCB), a challenging code benchmark designed to mirror the complexity and variety of scenarios in real coding tasks. NCB comprises 402 high-quality problems in Python and Java, meticulously selected from natural user queries from online coding services, covering 6 different domains. Noting the extraordinary difficulty in creating testing cases for real-world queries, we also introduce a semi-automated pipeline to enhance the efficiency of test case construction. Comparing with manual solutions, it achieves an efficiency increase of more than 4 times. Our systematic experiments on 39 LLMs find that performance gaps on NCB between models with close HumanEval scores could still be significant, indicating a lack of focus on practical code synthesis scenarios or over-specified optimization on HumanEval. On the other hand, even the best-performing GPT-4 is still far from satisfying on NCB. The evaluation toolkit and development set are available at https://github.com/THUDM/NaturalCodeBench.
- Level
- University Undergraduates and entry-level professionals
- Scored
- Checked automatically A program checks the result against an answer key, unit tests or the expected final state.
- Answers
- Code A program or patch run against tests.
Seed-Coder-8B-Instruct leads with 49.6%
Best score per model as labs report them in their own cards. Labs pick their own settings, so these compare less cleanly than independent runs.
- 1
Seed-Coder-8B-Instruct 49.6%
- 2
Seed Diffusion Preview 42.2%
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | | 49.6% | Jun 2025 | Model card | |
| 2 | | 42.2% | Jul 2025 | Model card |
Number one over time
Lab claims count from the day the card came out, independent runs from the model’s release.
Scores over time
All the scores we have, one dot each, so a model tested at several settings appears more than once.
No launch post has listed it since Jul 2025
Launch posts from every lab that has listed it, one tick per post. Tall colored ticks include it, and short gray ones leave it out.
| Date | Launch post | Score | As the post writes it |
|---|---|---|---|
| 31 Jul 2025 | 42.2 | NaturalCodeBench Total |
2 system cards report it, from 1 lab
Besides launch posts, we read the system cards, model cards and technical reports labs publish with a release. They report far more, including safety and frontier-risk tests.
| Date | Document | Score | As the document writes it | Section |
|---|---|---|---|---|
| 4 Aug 2025 | | 42.2 | NaturalCodeBench Total, NCB (zh) 45.8, NCB (en) 38.6 (Table 3) | Capabilities |
| 4 Jun 2025 | | 49.6 | NaturalCodeBench Total (Table 9). NCB (zh) 50.7, NCB (en) 48.6 | Capabilities |
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