| --- |
| library_name: transformers |
| license: other |
| license_name: lfm1.0 |
| license_link: LICENSE |
| language: |
| - en |
| - ar |
| - zh |
| - fr |
| - de |
| - ja |
| - ko |
| - es |
| pipeline_tag: text-generation |
| tags: |
| - liquid |
| - lfm2.5 |
| - edge |
| base_model: LiquidAI/LFM2.5-1.2B-Base |
| --- |
| |
| <div align="center"> |
| <img |
| src="https://cdn-uploads.huggingface.co/production/uploads/61b8e2ba285851687028d395/2b08LKpev0DNEk6DlnWkY.png" |
| alt="Liquid AI" |
| style="width: 100%; max-width: 100%; height: auto; display: inline-block; margin-bottom: 0.5em; margin-top: 0.5em;" |
| /> |
| <div style="display: flex; justify-content: center; gap: 0.5em; margin-bottom: 1em;"> |
| <a href="https://playground.liquid.ai/"><strong>Try LFM</strong></a> • |
| <a href="https://docs.liquid.ai/lfm"><strong>Documentation</strong></a> • |
| <a href="https://leap.liquid.ai/"><strong>LEAP</strong></a> |
| </div> |
| </div> |
| |
| # LFM2.5-1.2B-Instruct |
|
|
| LFM2.5 is a new family of hybrid models designed for **on-device deployment**. It builds on the LFM2 architecture with extended pre-training and reinforcement learning. |
|
|
| - **Best-in-class performance**: A 1.2B model rivaling much larger models, bringing high-quality AI to your pocket. |
| - **Fast edge inference**: 239 tok/s decode on AMD CPU, 82 tok/s on mobile NPU. Runs under 1GB of memory with day-one support for llama.cpp, MLX, and vLLM. |
| - **Scaled training**: Extended pre-training from 10T to 28T tokens and large-scale multi-stage reinforcement learning. |
|
|
|  |
|
|
| Find more information about LFM2.5 in our [blog post](https://www.liquid.ai/blog/introducing-lfm2-5-the-next-generation-of-on-device-ai). |
|
|
| ## 🗒️ Model Details |
|
|
| | Model | Parameters | Description | |
| |-------|------------|-------------| |
| | [LFM2.5-1.2B-Base](https://huggingface.co/LiquidAI/LFM2.5-1.2B-Base) | 1.2B | Pre-trained base model for fine-tuning | |
| | [**LFM2.5-1.2B-Instruct**](https://huggingface.co/LiquidAI/LFM2.5-1.2B-Instruct) | 1.2B | General-purpose instruction-tuned model | |
| | [LFM2.5-1.2B-Thinking](https://huggingface.co/LiquidAI/LFM2.5-1.2B-Thinking) | 1.2B | General-purpose reasoning model | |
| | [LFM2.5-1.2B-JP](https://huggingface.co/LiquidAI/LFM2.5-1.2B-JP) | 1.2B | Japanese-optimized chat model | |
| | [LFM2.5-VL-1.6B](https://huggingface.co/LiquidAI/LFM2.5-VL-1.6B) | 1.6B | Vision-language model with fast inference | |
| | [LFM2.5-Audio-1.5B](https://huggingface.co/LiquidAI/LFM2.5-Audio-1.5B) | 1.5B | Audio-language model for speech and text I/O | |
|
|
| LFM2.5-1.2B-Instruct is a general-purpose text-only model with the following features: |
|
|
| - **Number of parameters**: 1.17B |
| - **Number of layers**: 16 (10 double-gated LIV convolution blocks + 6 GQA blocks) |
| - **Training budget**: 28T tokens |
| - **Context length**: 32,768 tokens |
| - **Vocabulary size**: 65,536 |
| - **Knowledge cutoff**: Mid-2024 |
| - **Languages**: English, Arabic, Chinese, French, German, Japanese, Korean, Spanish |
| - **Generation parameters**: |
| - `temperature: 0.1` |
| - `top_k: 50` |
| - `top_p: 0.1` |
| - `repetition_penalty: 1.05` |
|
|
| | Model | Description | |
| |-------|-------------| |
| | [**LFM2.5-1.2B-Instruct**](https://huggingface.co/LiquidAI/LFM2.5-1.2B-Instruct) | Original model checkpoint in native format. Best for fine-tuning or inference with Transformers and vLLM. | |
| | [LFM2.5-1.2B-Instruct-GGUF](https://huggingface.co/LiquidAI/LFM2.5-1.2B-Instruct-GGUF) | Quantized format for llama.cpp and compatible tools. Optimized for CPU inference and local deployment with reduced memory usage. | |
| | [LFM2.5-1.2B-Instruct-ONNX](https://huggingface.co/LiquidAI/LFM2.5-1.2B-Instruct-ONNX) | ONNX Runtime format for cross-platform deployment. Enables hardware-accelerated inference across diverse environments (cloud, edge, mobile). | |
| | [LFM2.5-1.2B-Instruct-MLX](https://huggingface.co/LiquidAI/LFM2.5-1.2B-Instruct-MLX-8bit) | MLX format for Apple Silicon. Optimized for fast inference on Mac devices using the MLX framework. | |
|
|
| We recommend using it for agentic tasks, data extraction, and RAG. It is not recommended for knowledge-intensive tasks and programming. |
|
|
| ### Chat Template |
|
|
| LFM2.5 uses a ChatML-like format. See the [Chat Template documentation](https://docs.liquid.ai/lfm/key-concepts/chat-template) for details. Example: |
|
|
| ``` |
| <|startoftext|><|im_start|>system |
| You are a helpful assistant trained by Liquid AI.<|im_end|> |
| <|im_start|>user |
| What is C. elegans?<|im_end|> |
| <|im_start|>assistant |
| ``` |
|
|
| You can use [`tokenizer.apply_chat_template()`](https://huggingface.co/docs/transformers/en/chat_templating#using-applychattemplate) to format your messages automatically. |
|
|
| ### Tool Use |
|
|
| LFM2.5 supports function calling as follows: |
|
|
| 1. **Function definition**: We recommend providing the list of tools as a JSON object in the system prompt. You can also use the [`tokenizer.apply_chat_template()`](https://huggingface.co/docs/transformers/en/chat_extras#passing-tools) function with tools. |
| 2. **Function call**: By default, LFM2.5 writes Pythonic function calls (a Python list between `<|tool_call_start|>` and `<|tool_call_end|>` special tokens), as the assistant answer. You can override this behavior by asking the model to output JSON function calls in the system prompt. |
| 3. **Function execution**: The function call is executed, and the result is returned as a "tool" role. |
| 4. **Final answer**: LFM2 interprets the outcome of the function call to address the original user prompt in plain text. |
|
|
| See the [Tool Use documentation](https://docs.liquid.ai/lfm/key-concepts/tool-use) for the full guide. Example: |
|
|
| ``` |
| <|startoftext|><|im_start|>system |
| List of tools: [{"name": "get_candidate_status", "description": "Retrieves the current status of a candidate in the recruitment process", "parameters": {"type": "object", "properties": {"candidate_id": {"type": "string", "description": "Unique identifier for the candidate"}}, "required": ["candidate_id"]}}]<|im_end|> |
| <|im_start|>user |
| What is the current status of candidate ID 12345?<|im_end|> |
| <|im_start|>assistant |
| <|tool_call_start|>[get_candidate_status(candidate_id="12345")]<|tool_call_end|>Checking the current status of candidate ID 12345.<|im_end|> |
| <|im_start|>tool |
| [{"candidate_id": "12345", "status": "Interview Scheduled", "position": "Clinical Research Associate", "date": "2023-11-20"}]<|im_end|> |
| <|im_start|>assistant |
| The candidate with ID 12345 is currently in the "Interview Scheduled" stage for the position of Clinical Research Associate, with an interview date set for 2023-11-20.<|im_end|> |
| ``` |
|
|
| ## 🏃 Inference |
|
|
| LFM2.5 is supported by many inference frameworks. See the [Inference documentation](https://docs.liquid.ai/lfm/inference/transformers) for the full list. |
|
|
| | Name | Description | Docs | Notebook | |
| |------|-------------|------|:--------:| |
| | [Transformers](https://github.com/huggingface/transformers) | Simple inference with direct access to model internals. | <a href="https://docs.liquid.ai/lfm/inference/transformers">Link</a> | <a href="https://colab.research.google.com/drive/1_q3jQ6LtyiuPzFZv7Vw8xSfPU5FwkKZY?usp=sharing"><img src="https://cdn-uploads.huggingface.co/production/uploads/61b8e2ba285851687028d395/vlOyMEjwHa_b_LXysEu2E.png" width="110" alt="Colab link"></a> | |
| | [vLLM](https://github.com/vllm-project/vllm) | High-throughput production deployments with GPU. | <a href="https://docs.liquid.ai/lfm/inference/vllm">Link</a> | <a href="https://colab.research.google.com/drive/1VfyscuHP8A3we_YpnzuabYJzr5ju0Mit?usp=sharing"><img src="https://cdn-uploads.huggingface.co/production/uploads/61b8e2ba285851687028d395/vlOyMEjwHa_b_LXysEu2E.png" width="110" alt="Colab link"></a> | |
| | [llama.cpp](https://github.com/ggml-org/llama.cpp) | Cross-platform inference with CPU offloading. | <a href="https://docs.liquid.ai/lfm/inference/llama-cpp">Link</a> | <a href="https://colab.research.google.com/drive/1ohLl3w47OQZA4ELo46i5E4Z6oGWBAyo8?usp=sharing"><img src="https://cdn-uploads.huggingface.co/production/uploads/61b8e2ba285851687028d395/vlOyMEjwHa_b_LXysEu2E.png" width="110" alt="Colab link"></a> | |
| | [MLX](https://github.com/ml-explore/mlx) | Apple's machine learning framework optimized for Apple Silicon. | <a href="https://docs.liquid.ai/lfm/inference/mlx">Link</a> | — | |
| | [LM Studio](https://lmstudio.ai/) | Desktop application for running LLMs locally. | <a href="https://docs.liquid.ai/lfm/inference/lm-studio">Link</a> | — | |
|
|
| Here's a quick start example with Transformers: |
|
|
| ```python |
| from transformers import AutoModelForCausalLM, AutoTokenizer, TextStreamer |
| |
| model_id = "LiquidAI/LFM2.5-1.2B-Instruct" |
| model = AutoModelForCausalLM.from_pretrained( |
| model_id, |
| device_map="auto", |
| dtype="bfloat16", |
| # attn_implementation="flash_attention_2" <- uncomment on compatible GPU |
| ) |
| tokenizer = AutoTokenizer.from_pretrained(model_id) |
| streamer = TextStreamer(tokenizer, skip_prompt=True, skip_special_tokens=True) |
| |
| prompt = "What is C. elegans?" |
| |
| input_ids = tokenizer.apply_chat_template( |
| [{"role": "user", "content": prompt}], |
| add_generation_prompt=True, |
| return_tensors="pt", |
| tokenize=True, |
| ).to(model.device) |
| |
| output = model.generate( |
| input_ids, |
| do_sample=True, |
| temperature=0.1, |
| top_k=50, |
| top_p=0.1, |
| repetition_penalty=1.05, |
| max_new_tokens=512, |
| streamer=streamer, |
| ) |
| ``` |
|
|
| ## 🔧 Fine-Tuning |
|
|
| We recommend fine-tuning LFM2.5 for your specific use case to achieve the best results. |
|
|
| | Name | Description | Docs | Notebook | |
| |------|-------------|------|----------| |
| | CPT ([Unsloth](https://github.com/unslothai/unsloth)) | Continued Pre-Training using Unsloth for text completion. | <a href="https://docs.liquid.ai/lfm/fine-tuning/unsloth">Link</a> | <a href="https://colab.research.google.com/drive/10fm7eNMezs-DSn36mF7vAsNYlOsx9YZO?usp=sharing"><img src="https://cdn-uploads.huggingface.co/production/uploads/61b8e2ba285851687028d395/vlOyMEjwHa_b_LXysEu2E.png" width="110" alt="Colab link"></a> | |
| | CPT ([Unsloth](https://github.com/unslothai/unsloth)) | Continued Pre-Training using Unsloth for translation. | <a href="https://docs.liquid.ai/lfm/fine-tuning/unsloth">Link</a> | <a href="https://colab.research.google.com/drive/1gaP8yTle2_v35Um8Gpu9239fqbU7UgY8?usp=sharing"><img src="https://cdn-uploads.huggingface.co/production/uploads/61b8e2ba285851687028d395/vlOyMEjwHa_b_LXysEu2E.png" width="110" alt="Colab link"></a> | |
| | SFT ([Unsloth](https://github.com/unslothai/unsloth)) | Supervised Fine-Tuning with LoRA using Unsloth. | <a href="https://docs.liquid.ai/lfm/fine-tuning/unsloth">Link</a> | <a href="https://colab.research.google.com/drive/1vGRg4ksRj__6OLvXkHhvji_Pamv801Ss?usp=sharing"><img src="https://cdn-uploads.huggingface.co/production/uploads/61b8e2ba285851687028d395/vlOyMEjwHa_b_LXysEu2E.png" width="110" alt="Colab link"></a> | |
| | SFT ([TRL](https://github.com/huggingface/trl)) | Supervised Fine-Tuning with LoRA using TRL. | <a href="https://docs.liquid.ai/lfm/fine-tuning/trl">Link</a> | <a href="https://colab.research.google.com/drive/1j5Hk_SyBb2soUsuhU0eIEA9GwLNRnElF?usp=sharing"><img src="https://cdn-uploads.huggingface.co/production/uploads/61b8e2ba285851687028d395/vlOyMEjwHa_b_LXysEu2E.png" width="110" alt="Colab link"></a> | |
| | DPO ([TRL](https://github.com/huggingface/trl)) | Direct Preference Optimization with LoRA using TRL. | <a href="https://docs.liquid.ai/lfm/fine-tuning/trl">Link</a> | <a href="https://colab.research.google.com/drive/1MQdsPxFHeZweGsNx4RH7Ia8lG8PiGE1t?usp=sharing"><img src="https://cdn-uploads.huggingface.co/production/uploads/61b8e2ba285851687028d395/vlOyMEjwHa_b_LXysEu2E.png" width="110" alt="Colab link"></a> | |
| | GRPO ([Unsloth](https://github.com/unslothai/unsloth)) | GRPO with LoRA using Unsloth. | <a href="https://docs.liquid.ai/lfm/fine-tuning/unsloth">Link</a> | <a href="https://colab.research.google.com/drive/1mIikXFaGvcW4vXOZXLbVTxfBRw_XsXa5?usp=sharing"><img src="https://cdn-uploads.huggingface.co/production/uploads/61b8e2ba285851687028d395/vlOyMEjwHa_b_LXysEu2E.png" width="110" alt="Colab link"></a> | |
|
|
| ## 📊 Performance |
|
|
| ### Benchmarks |
|
|
| We compared LFM2.5-1.2B-Instruct with relevant sub-2B models on a diverse suite of benchmarks. |
|
|
| | Model | GPQA | MMLU-Pro | IFEval | IFBench | Multi-IF | AIME25 | BFCLv3 | |
| |-------|------|----------|--------|---------|----------|--------|--------| |
| | **LFM2.5-1.2B-Instruct** | 38.89 | 44.35 | 86.23 | 47.33 | 60.98 | 14.00 | 49.12 | |
| | Qwen3-1.7B (instruct)| 34.85 | 42.91 | 73.68 | 21.33 | 56.48 | 9.33 | 46.30 | |
| | Granite 4.0-1B | 24.24 | 33.53 | 79.61 | 21.00 | 43.65 | 3.33 | 52.43 | |
| | Llama 3.2 1B Instruct | 16.57 | 20.80 | 52.37 | 15.93 | 30.16 | 0.33 | 21.44 | |
| | Gemma 3 1B IT | 24.24 | 14.04 | 63.25 | 20.47 | 44.31 | 1.00 | 16.64 | |
|
|
| GPQA, MMLU-Pro, IFBench, and AIME25 follow [ArtificialAnalysis's methodology](https://artificialanalysis.ai/methodology/intelligence-benchmarking). For IFEval and Multi-IF, we report the average score across strict and loose prompt and instruction accuracies. For BFCLv3, we report the final weighted average score with a custom Liquid handler to support our tool use template. |
|
|
| ### Inference speed |
|
|
| LFM2.5-1.2B-Instruct offers extremely fast inference speed on CPUs with a low memory profile compared to similar-sized models. |
|
|
|  |
|
|
| In addition, we are partnering with AMD, Qualcomm, and Nexa AI to bring the LFM2.5 family to NPUs. These optimized models are available through our partners, enabling highly efficient on-device inference. |
| The following numbers have been calculated using 1K prefill and 100 decode tokens: |
|
|
| | Device | Inference | Framework | Model | Prefill (tok/s) | Decode (tok/s) | Memory (GB) | |
| | ---------------------------------------------------- | --------- | ---------------- | -------------------- | --------------- | -------------- | ----------- | |
| | Qualcomm Snapdragon® X Elite | NPU | NexaML | LFM2.5-1.2B-Instruct | 2591 | 63 | 0.9GB | |
| | Qualcomm Snapdragon® Gen4 (ROG Phone9 Pro) | NPU | NexaML | LFM2.5-1.2B-Instruct | 4391 | 82 | 0.9GB | |
| | Qualcomm Snapdragon® Gen4 (Samsung Galaxy S25 Ultra) | CPU | llama.cpp (Q4_0) | LFM2.5-1.2B-Instruct | 335 | 70 | 719MB | |
| | Qualcomm Snapdragon® Gen4 (Samsung Galaxy S25 Ultra) | CPU | llama.cpp (Q4_0) | Qwen3-1.7B | 181 | 40 | 1306MB | |
|
|
| These capabilities unlock new deployment scenarios across various devices, including vehicles, mobile devices, laptops, IoT devices, and embedded systems. |
|
|
| ## Contact |
|
|
| For enterprise solutions and edge deployment, contact [sales@liquid.ai](mailto:sales@liquid.ai). |
|
|
| ## Citation |
|
|
| ```bibtex |
| @article{liquidai2025lfm2, |
| title={LFM2 Technical Report}, |
| author={Liquid AI}, |
| journal={arXiv preprint arXiv:2511.23404}, |
| year={2025} |
| } |
| ``` |