JetBrains Mellum2.1 Card - LiveCodeBench v6: leaderboard

LiveCodeBench v6 competitive-programming problems. JetBrains evaluated Mellum2.1 Thinking, Mellum2 Thinking, Gemma 4 E4B and Qwen3.5 9B with the same pipeline in thinking mode (greedy decoding) and reported the results on the Mellum2.1 model card (October 2026). Vendor-reported. Metric: Pass@1 (%). Higher is better. Source: https://huggingface.co/JetBrains/Mellum2.1-12B-A2.5B-Thinking/raw/92ddae9fc7665e9f801d141d2e5a6b2caf2460c4/README.md

Metric: Pass@1 (%). Source: huggingface.co. Saturation forecast: Around January 2027. 4 models tracked.

Top models

#ModelScoreOverall rank
1Qwen 3.5 9B (Thinking)75.4#377 (Qwen 3.5 9B)
2Gemma 4 E4B (IT) (Thinking)69.4

No result here: #3 Claude Opus 5.5, #6 GPT-6 Astra, #7 GPT-6.1 Sol.

Interactive version: theaggregate.ai/benchmark?slug=jetbrains-mellum2-1-card-livecodebench-v6 · How It Works · Data refreshed daily, snapshot 2026-10-19.