We’re introducing gpt-oss RL support and the fastest RL inference and lowest VRAM use vs. any implementation. Blog: https://docs.unsloth.ai/new/gpt-oss-reinforcement-learning

• Unsloth now offers the fastest inference (~3x faster), lowest VRAM (50% less) and most context (8x longer) for gpt-oss RL vs. any implementation - with no accuracy loss.
• Since RL on gpt-oss isn't yet vLLM compatible, we rewrote Transformers inference code to enable faster inference
• gpt-oss-20b GSPO free Colab notebook
• This notebook automatically creates faster matrix multiplication kernels and uses a new Unsloth reward function. We also show how to counteract reward-hacking which is one of RL's biggest challenges.

• We previously released Vision RL with GSPO support
• ⚠️ Reminder to NOT use Flash Attention 3 for gpt-oss as it'll make your training loss wrong.
• DeepSeek-V3.1-Terminus is here and you can run locally via our GGUF Read how our 3-bit GGUF beats Claude-4-Opus (thinking) on Aider Polyglot here
• Magistral 1.2 is here and you can run it locally here or fine-tune it for free by using our Kaggle notebook
• Fine-tuning the new Qwen3 models including Qwen3-VL, Qwen3-Omni and Qwen3-Next should work in Unsloth if you install the latest transformers. The models are big however so ensure you have enough VRAM.
• BERT is now fixed! Feel free to use our BERT fine-tuning notebook

Don't forget to also join our Reddit: r/unsloth 🥰

What's Changed

• Bug fixes by @danielhanchen in https://github.com/unslothai/unsloth/pull/3329
• Fix QAT + LoRA fast path, add tests by @andrewor14 in https://github.com/unslothai/unsloth/pull/3307
• Use gemma3n embedder patch + adjust FORCE_FLOAT32 match logic by @mmathew23 in https://github.com/unslothai/unsloth/pull/3332
• Synthetic Data updates by @mmathew23 in https://github.com/unslothai/unsloth/pull/3333
• Fix loading issues for BERT by @Etherll in https://github.com/unslothai/unsloth/pull/3339
• Bug fixes by @danielhanchen in https://github.com/unslothai/unsloth/pull/3335
• peft_config before model_config by @mmathew23 in https://github.com/unslothai/unsloth/pull/3342
• specify different tokenizer_path/name by @mmathew23 in https://github.com/unslothai/unsloth/pull/3343
• correct python support statement by @laz-001 in https://github.com/unslothai/unsloth/pull/3374
• GPT OSS RL by @danielhanchen in https://github.com/unslothai/unsloth/pull/3362

New Contributors

• @laz-001 made their first contribution in https://github.com/unslothai/unsloth/pull/3374

Full Changelog: https://github.com/unslothai/unsloth/compare/September-2025-v2...September-2025-v3