# OpenAI Says GPT-6 Astra Passes 87.4% of MultiLangBench Tests Across 20 Languages Including COBOL and Fortran

Times of AI Desk · 2026-10-20 · Research

[https://timesof.ai/2026/10/openai-multilangbench-cobol-fortran-low-resource](https://timesof.ai/2026/10/openai-multilangbench-cobol-fortran-low-resource)

> OpenAI reported on Oct. 19 that GPT-6 Astra averages 87.4% on MultiLangBench, a new GitHub benchmark that builds a SQLite-compatible engine across 20 low-resource languages, up from 26.8% for GPT-5.6 Sol. COBOL rises from 10.9 to 72.1 and Fortran from 21.4 to 83.5, OpenAI says. All figures are OpenAI's own.

Legacy-code migration is one of the few enterprise AI markets with clear budgets, and OpenAI is pitching straight at it — on a benchmark it built. In a **Monday, October 19** post, **OpenAI** said **GPT-6 Astra** averages **87.4%** across 20 low-resource languages on **MultiLangBench**, which asks models to build a SQLite-compatible database engine, up from **26.8%** for GPT-5.6 Sol. COBOL rises from 10.9 to **72.1** and Fortran from 21.4 to **83.5**, OpenAI reports. GPT-6 Luna averages 40.3% at an estimated **$0.77** per sample against **$3.48** for GPT-5.6 Sol.

On a COBOL-to-C++/Java/Kotlin/Python/Rust migration test scored on byte-for-byte output parity, **GPT-6.1 Sol** reaches **86.6%** at low reasoning effort against 5.4% for GPT-5.6 Sol, at **61%** of the API cost, and **97.9%** at higher effort, OpenAI says. It released MultiLangBench on GitHub and says expert review is still needed. We covered [Astra's launch](https://timesof.ai/2026/09/openai-gpt-6-astra) separately.

## Limits

- Every number is OpenAI's, on a benchmark it built.

## Sources

- [OpenAI: Advancing coding in low-resource programming languages (October 19, 2026)](https://openai.com/index/low-resource-programming-languages/)
- [Times of AI: GPT-6 Astra launch (September 3, 2026)](https://timesof.ai/2026/09/openai-gpt-6-astra)