slime alternatives
Curated alternatives to slime — and why you'd switch.
verl
ByteDance's RL post-training library (HybridFlow): PPO/GRPO dataflows in a few lines, FSDP/Megatron training with vLLM/SGLang rollouts, production-proven at frontier scale.
Why switchSame job — large-scale RL post-training. verl bets on multi-backend flexibility (FSDP/Megatron × vLLM/SGLang) where slime hard-commits to Megatron+SGLang; pick verl when your infra is vLLM- or FSDP-shaped.
Full comparison →trl
Hugging Face's post-training library: SFT, DPO, GRPO, KTO and reward-model trainers on top of Transformers — from a Colab LoRA run to multi-GPU deployments.
Why switchThe lighter trainer slime's own docs point you toward: single-node SFT/LoRA/DPO on the HF stack instead of Megatron-scale RL infrastructure. Same goal — a post-trained model — at opposite ends of the infra spectrum.
Full comparison →h2o-llmstudio
H2O's no-code GUI and framework for fine-tuning LLMs — LoRA, 8-bit, DPO and experiment tracking behind a web UI, with CLI and Docker paths for the same configs.
Why switchBoth post-train LLMs, from opposite ends: slime is Megatron-scale RL for frontier runs, LLM Studio is no-code LoRA/DPO fine-tuning on models a single node can hold.
Full comparison →