📖 The AI Tool Bible

Fine-tuning

Train and host custom models on your own data.

33 tools

Why it matters

Fine-tuning has gone from "deep ML team only" to "a few hours of JSONL away" — but the choice between closed-model FT (OpenAI), open-model FT (Together, Modal), and memory-tuning matters more than ever.

What's in here

Covers closed-model fine-tuning (OpenAI), open-model FT + serving (Together AI, Replicate, Modal), distributed training platforms (Anyscale), and specialised platforms (Lamini for factual recall).

How to pick

Pick OpenAI for the easiest UX on closed models. Pick Together AI for open-model FT + serving in one place. Pick Modal for serverless GPU control. Pick Lamini specifically for hallucination-free factual recall.

Ray Tune

Fine-tuning

Open-source Python library for distributed hyperparameter tuning at any scale.

Free· Open-source (Apache 2.0); managed via Anyscale offers a $100 starting credithyperparameter-tuningdistributed-training

RunPod

Fine-tuning · Bring-your-own (any open-weight or custom model)

On-demand GPU cloud and serverless inference platform built specifically for AI workloads.

Paid· Pay-per-second GPU rental; H100 from ~$1.89/hr, consumer GPUs from ~$0.20/hrllm-fine-tuninggpu-rental

SGLang

Fine-tuning · Multi-model (DeepSeek, Qwen, Llama, Mistral, GLM, GPT-OSS)

Open-source high-throughput inference engine for LLMs and multimodal models with OpenAI-compatible serving.

Free· Free, open-source (Apache 2.0); self-hosted infra cost onlyllm-servingmultimodal-inference

Scale GenAI Platform

Fine-tuning · Multi-model (OpenAI, Google, Meta, Mistral)

Enterprise agent platform from Scale AI that connects your data, orchestrates multi-agent workflows, and learns from human feedback inside your own VPC.

Enterprise· Contact sales; enterprise contracts onlyenterprise-agentsrag-over-internal-data

Together AI Fine-tuning

Fine-tuning · Multi-model (any Hugging Face open-source model)

Managed fine-tuning platform for open-source LLMs and vision models with LoRA, full fine-tuning, and RL support.

Paid· Usage-based; cost estimator in-product, no public price listllm-fine-tuningvision-fine-tuning

Unsloth

Fine-tuning · Llama, Mistral, Gemma, Qwen, GLM (multi-model)

Open-source LLM fine-tuning toolkit with custom kernels that train 2-30x faster and use up to 90% less VRAM.

Freemium· Free open-source; Pro and Enterprise contact saleslora-finetuningqlora

Velda

Fine-tuning

Serverless GPU orchestration that runs AI training and batch jobs without Docker or Kubernetes.

Freemium· Free monthly credits on Velda Cloud; Enterprise contact salesdistributed-trainingbatch-inference

W&B Sweeps

Fine-tuning

Hyperparameter optimization from Weights & Biases with Bayesian search and Hyperband early stopping.

Freemium· Free for personal use; team and enterprise tiers via W&Bhyperparameter-tuningbayesian-optimization

vLLM

Fine-tuning · Multi-model (open-weight LLMs: Llama, Qwen, DeepSeek, Mistral, Gemma, Phi, etc.)

Open-source high-throughput inference engine for serving LLMs with PagedAttention and continuous batching.

Free· Free and open-source (Apache 2.0); self-hosted infrastructure costs applyllm-servingself-hosted-inference