Axolotl
Free open-source LLM & multimodal fine-tuning framework with latest model support and advanced parallelism.
Axolotl is the most feature-complete open-source fine-tuning framework, unmatched in model support and parallelism options. It's the top choice for researchers who need to train on the latest models (Gemma 4, Mistral 3.5) without spending on APIs. However, the steep learning curve and lack of GUI limit it to technical users willing to manage their own infrastructure.
Verified 17d ago · liveness 80/100 · cite: rightaichoice.com/tools/axolotl
- Researchers fine-tuning LLMs with latest techniques like GRPO, GDPO, or QAT
- Developers needing to fine-tune multimodal models on custom datasets
- Teams requiring efficient multi-node training with FSDP, DeepSpeed, or ND parallelism
- Anyone wanting a free, open-source alternative to managed fine-tuning APIs
- Non-technical users seeking a GUI-based fine-tuning tool
- Production deployments requiring enterprise support or SLA
- Users who need built-in data labeling or dataset management
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Skip Axolotl if you need a GUI or managed service for fine-tuning and prefer not to manage your own GPU infrastructure.
You must supply your own GPU compute—cloud GPU costs (e.g., RunPod, AWS) can exceed $2/hour for high-end instances like A100 or H100.
Axolotl is free and open-source under Apache 2.0, making it the most cost-effective option for teams with existing GPU infrastructure. Compared to managed APIs like Replicate (pay per token) or managed fine-tuning services (e.g., Hugging Face AutoTrain at $10+/hour), Axolotl can be cheaper for high-volume training but requires upfront engineering investment.
In short
Axolotl — Free open-source LLM & multimodal fine-tuning framework with latest model support and advanced parallelism. Best for Researchers fine-tuning LLMs with latest techniques like GRPO, GDPO, or QAT, Developers needing to fine-tune multimodal models on custom datasets, Teams requiring efficient multi-node training with FSDP, DeepSpeed, or ND parallelism. Free to use.
What's new in Axolotl
Checked 15 days agoAcross the latest 5 updates: 5 feature updates.
New model support: Mistral Medium 3.5 and Gemma 4; uv-first packaging; SonicMoE fused LoRA
Added Mistral Medium 3.5 and Gemma 4 support. Moved to uv-first packaging and added SonicMoE fused LoRA support.
New models and MoE expert quantization
Added Mistral Small 4, Qwen3.5, GLM-4.7-Flash, GLM-4.6V, GLM-4.5-Air. Introduced MoE expert quantization via quantize_moe_experts.
ScatterMoE LoRA and SageAttention integration
Added ScatterMoE LoRA using custom Triton kernels, SageAttention integration, and GDPO (Generalized DPO) support.
EAFT and Scalable Softmax
Introduced Entropy-Aware Focal Training (EAFT) and Scalable Softmax for improved long context attention.
Kimi-Linear, Plano-Orchestrator, Distributed Muon Optimizer
Added Kimi-Linear, Plano-Orchestrator, MiMo, InternVL 3.5, Olmo3, Trinity, Ministral3. Distributed Muon Optimizer for FSDP2 pretraining.
Viability Score
How likely is Axolotl to still be operational in 12 months? Based on 4 signals — momentum (how recently it shipped), wrapper dependency, revenue model, and web presence.
Last calculated: July 2026
How we score →Key Features
- Full fine-tuning with FSDP, DeepSpeed, and sequence parallelism
- LoRA and QLoRA with memory optimizations
- Preference tuning: DPO, IPO, KTO, ORPO, GDPO
- Reinforcement learning: GRPO, GDPO
- Reward modeling and process reward modeling (PRM)
- Quantization aware training (QAT) with NVFP4
- Multimodal training for VLMs (vision, video) and audio models
- ND parallelism combining CP, TP, FSDP across nodes
- Distributed Muon Optimizer for FSDP2 pretraining
- ScatterMoE LoRA and SonicMoE fused LoRA support
- MoE expert quantization via quantize_moe_experts
- SageAttention integration for efficient attention
- EAFT (Entropy-Aware Focal Training) for loss weighting
- Scalable Softmax for improved long-context attention
- YAML-based configuration system
About Axolotl
Axolotl is a free, open-source framework for fine-tuning and post-training large language models (LLMs) and multimodal models. It simplifies the process of adapting state-of-the-art models like Mistral Medium 3.5, Gemma 4, Qwen3.5, and GLM-4.7-Flash for custom tasks. Designed for researchers and engineers, Axolotl supports full fine-tuning, LoRA, QLoRA, preference tuning (DPO, IPO, KTO, ORPO, GDPO), reinforcement learning (GRPO, GDPO), and reward modeling including process reward modeling. It also handles vision-language models (VLMs), audio models (Voxtral), and text diffusion. Key features include advanced parallelism (FSDP, DeepSpeed, sequence parallelism, ND parallelism combining CP, TP, FSDP), a Distributed Muon Optimizer, ScatterMoE/SonicMoE fused LoRA, MoE expert quantization, FP8 training with torchao, SageAttention, EAFT (Entropy-Aware Focal Training), and Scalable Softmax for long context. The framework uses a YAML-based configuration system, making it flexible for infrastructure-managed pipelines. Recent updates (2026) add support for Mistral Medium 3.5 and Gemma 4, uv-first packaging, SonicMoE fused LoRA, and improved MoE expert quantization. Axolotl is ideal for those who need cutting-edge fine-tuning techniques without vendor lock-in, but requires comfort with command-line tools and YAML configs. Compared to managed APIs like OpenAI or Hugging Face Trainer, Axolotl offers maximum customization and cost savings for GPU-equipped teams. It outpaces Unsloth in breadth of model support and training techniques, but lacks a GUI and enterprise support.
Behind the Verdict
Axolotl is a powerhouse for anyone who needs to fine-tune the newest models on custom data without paying per-token fees. The breadth of supported training techniques — from QLoRA to GDPO to Scalable Softmax — is unmatched among open-source tools. If you're a researcher or ML engineer comfortable with YAML and the command line, Axolotl gives you near-total control over the training pipeline. Where it falls short is accessibility. Non-technical users or teams that need a click-and-train solution should look elsewhere — Unsloth offers a simpler notebook experience, and Hugging Face Trainer has better integration with the HF ecosystem. Axolotl also doesn't include built-in dataset management or labeling, so you'll need separate tools for data prep. In practice, we'd reach for Axolotl when we need to fine-tune a model that just dropped (like Gemma 4) or when we want to experiment with advanced parallelism (ND parallelism across nodes). The community is active, but documentation can be dense. For production deployments, you'll need your own monitoring and error handling. Bottom line: Axolotl is the best free option for researchers who want cutting-edge methods and aren't afraid of YAML. For others, the learning curve may outweigh the benefits.
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Real-world workflow fit
Concrete scenarios for the personas Axolotl actually fits — and what changes day-one when you adopt it.
You have a dataset of domain-specific instruction pairs and want to fine-tune Gemma 4 using QLoRA on 4x A100s.
Outcome: Write a YAML config specifying base_model: google/gemma-4, lora, dataset paths, and run axolotl to produce a fine-tuned model checkpoint in hours.
You need to automate retraining a chatbot model weekly using the latest Qwen3.5 checkpoint.
Outcome: Integrate Axolotl into a GitHub Actions workflow: on schedule, clone the repo, run training with a predefined YAML config, and upload the checkpoint to Hugging Face Hub.
You have a few hundred labeled images and want to fine-tune a small VLM (e.g., SmolVLM2) for a personal project.
Outcome: Use the multimodal training support with a YAML config for LoRA; Axolotl handles data formatting and training on a single consumer GPU (RTX 4090).
Use Cases
- Fine-tune a custom chatbot on enterprise support tickets to improve response accuracy.
- Adapt a pretrained model to specialized domain terminology (e.g., legal, medical).
- Experiment with different fine-tuning methods (LoRA, QLoRA, preference tuning) to balance cost and quality.
- Reproduce fine-tuning experiments across different hardware setups.
- Convert a fine-tuned model to GGUF for deployment on edge devices.
- Integrate Axolotl into a CI/CD pipeline for automated model retraining.
- Fine-tune a multimodal VLM on custom image-text pairs for visual question answering.
Models Under the Hood
as of 2026-07-14
Limitations
- Axolotl is a command-line tool with no hosted service, so you must manage your own infrastructure.
- It has no built-in API for inference or model serving.
- The learning curve is moderate, requiring familiarity with YAML configuration and training concepts.
as of 2026-07-02
Where the pricing makes sense
The company stage and team size where Axolotl's pricing actually pencils out — and where peers do it cheaper.
Axolotl is free and open-source under Apache 2.0, making it the most cost-effective option for teams with existing GPU infrastructure. Compared to managed APIs like Replicate (pay per token) or managed fine-tuning services (e.g., Hugging Face AutoTrain at $10+/hour), Axolotl can be cheaper for high-volume training but requires upfront engineering investment.
Setup time & first value
How long it actually takes to get something useful out of Axolotl — broken out by persona, not the marketing-page minute.
Time to first fine-tune depends on your familiarity: 1-2 hours for experienced users installing dependencies and running a sample config (e.g., Mistral-7B LoRA). Newcomers may need half a day to set up a Python environment, install PyTorch with CUDA, and understand YAML config options.
Switching to or from Axolotl
How to bring data in from common predecessors and how to get it back out — written for the switcher, not the buyer.
- →From Hugging Face Trainer: Replace your training script with a YAML config and leverage Axolotl's parallelism and advanced techniques like QLoRA or preference tuning.
- →From Unsloth: Axolotl supports more models and parallelism options but lacks Unsloth's memory-efficient kernels—expect similar workflow, different YAML schema.
- ↗To Unsloth: Simpler, faster LoRA for supported models (Mistral, Llama, Gemma) with lower memory usage; less flexible in model breadth and parallelism.
- ↗To Hugging Face Trainer: Better for simple fine-tuning with less overhead; no built-in QLoRA or ND parallelism but more documentation and community support.
- ↗To vLLM for inference: Export your Axolotl checkpoint to Hugging Face format and serve with vLLM for production inference.
Integrations
Resources & Guides
- Resourcegithub.com
GitHub
Go ahead and axolotl questions. Contribute to axolotl-ai-cloud/axolotl development by creating an account on GitHub.
- Examplesgithub.com
axolotl/examples at main
Go ahead and axolotl questions. Contribute to axolotl-ai-cloud/axolotl development by creating an account on GitHub.
- Documentationgithub.com
axolotl/docs at main
Go ahead and axolotl questions. Contribute to axolotl-ai-cloud/axolotl development by creating an account on GitHub.
Official links
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