OpenAI COBOL Migration: leaderboard
Migrate COBOL to C++, Java, Kotlin, Python or Rust; success requires byte-for-byte output parity on all hidden tests. Every published effort retained. The migration task is distinct from MultiLangBench; access to its exact input programs is not established by the hidden-grader description. All-Tests Pass Rate (%); higher is better.
Metric: All-Tests Pass Rate (%). Source: openai.com. Saturation forecast: Around January 2027. 20 models tracked.
Top models
| # | Model | Score | Overall rank |
|---|---|---|---|
| 1 | GPT-6.1 Sol (Max) | 97.9 | #7 (GPT-6.1 Sol) |
| 2 | GPT-6.1 Sol (xHigh) | 97.9 | #7 (GPT-6.1 Sol) |
| 3 | GPT-6.1 Sol (Medium) | 96.9 | #7 (GPT-6.1 Sol) |
| 4 | GPT-6 Astra (Max) | 96.8 | #6 (GPT-6 Astra) |
| 5 | GPT-6 Astra (xHigh) | 96.8 | #6 (GPT-6 Astra) |
| 6 | GPT-6.1 Sol (High) | 95.9 | #7 (GPT-6.1 Sol) |
| 7 | GPT-6 Sol (Max) | 95.8 | #14 (GPT-6 Sol) |
| 8 | GPT-6 Astra (Medium) | 95.8 | #6 (GPT-6 Astra) |
| 9 | GPT-6 Astra (High) | 95.7 | #6 (GPT-6 Astra) |
| 10 | GPT-6.1 Sol (Low) | 86.6 | #7 (GPT-6.1 Sol) |
| 11 | GPT-6 Astra (Low) | 86.3 | #6 (GPT-6 Astra) |
| 12 | GPT-6 Sol (xHigh) | 80.2 | #14 (GPT-6 Sol) |
| 13 | GPT-6 Sol (High) | 75.3 | #14 (GPT-6 Sol) |
| 14 | GPT-5.6 Sol (Max) | 65.2 | #19 (GPT-5.6 Sol) |
| 15 | GPT-5.6 Sol (xHigh) | 54.7 | #19 (GPT-5.6 Sol) |
No result here: #3 Claude Opus 5.5, #8 Gemini 4 Argon, #9 Claude Fable 5.1.
Interactive version: theaggregate.ai/benchmark?slug=openai-cobol-migration · How It Works · Data refreshed daily, snapshot 2026-10-20.