MiniCPM5 (1B and 2B)

MiniCPM5 (1B and 2B)

by OpenBMB (with Modelbest, THUNLP and RUC Gaoling School of AI)

Small open-weight LLMs for local and on-device use. Apache 2.0.

Lineage (then → 2026 now)

Earlier MiniCPM generations (2025 and before; not re-verified here) → MiniCPM5-1B (2026-05-19) → MiniCPM5-2B (2026-09-07, current top of the series). Related OpenBMB multimodal models listed on Hugging Face: MiniCPM-V 4.5 / 4.6 and MiniCPM-o 4.5 (full-duplex omni-modal).

Facts (Hugging Face cards, GitHub README)

• MiniCPM5-1B: 1.08B parameters (0.68B non-embedding), 24 layers, GQA (16 Q / 2 KV heads), 131,072-token context, Apache-2.0, standard LlamaForCausalLM. One checkpoint does fast answers and reasoning via enable_thinking. Post-trained with SFT + RL + on-policy distillation (OPD); base and SFT-only checkpoints also published. Released 2026-05-19 (per search summary of the GitHub README).
• MiniCPM5-2B: 2.5B parameters (1.98B non-embedding), 42 layers, 131K context, Apache-2.0, released 2026-09-07 (GitHub README). Card claims “2B-class open-source SOTA” with a 53.9 average over 40+ benchmarks (vendor comparison); a trade press report says it tops the Artificial Analysis index among models under 4B (secondary, unchecked). OpenBMB also released training data (UltraX web data, UltraData-Code, ~500K agent samples, 80K+ RL samples) per the card.
• Serving: vLLM, SGLang, llama.cpp, Transformers; the 2B also lists Ollama; GGUF, GPTQ and MLX builds exist.
• Both cards carry a tech-report reference dated 2025 (arXiv 2506.07900), which is the earlier MiniCPM report, not a MiniCPM5 paper.

Pricing

Open weights, free.

What changed in 2026

The earlier note covered only the 1B. The 2B arrived 2026-09-07 and is now the headline model. Informal observations carried over earlier (VRAM around 2 GB, Gradio demo, weak non-English output) were user remarks, not card claims, and are dropped.

Sources

• https://huggingface.co/openbmb/MiniCPM5-1B (accessed 2026-10-01)
• https://huggingface.co/openbmb/MiniCPM5-2B (accessed 2026-10-01)
• https://huggingface.co/openbmb (accessed 2026-10-01)
• https://github.com/openbmb/minicpm (accessed 2026-10-01)