The generative‑AI boom of the early 2020s has reshaped how businesses, developers and researchers build intelligent applications. From chatbots and summarization tools to creative writing assistants and code generators, large language models (LLMs) underpin many of the products we use every day. A recent market forecast predicts that the generative‑AI industry will grow from roughly USD 37.9 billion in 2025 to more than USD 1 trillion by 2034. That staggering figure illustrates both the scale of opportunity and the intensity of competition.
Within this landscape, open‑source LLMs have become a force for democratization. Unlike proprietary services that lock users into closed APIs, open models release their weights under permissive licences. According to an analysis published in early 2025, open‑source deployments account for more than half of the on‑premises LLM market and new releases have nearly doubled since early 2023. The implication is clear: organizations of all sizes are turning to open alternatives for transparency, cost control and customization. In this guide you’ll discover ten of the most influential open‑source LLMs as of 2025. We’ll explore their architectures, strengths and limitations, provide expert commentary and statistics, and show how Clarifai’s platform can help you harness them securely.
Before diving into individual models, here’s a concise overview of the top open‑source LLMs covered in this article. It summarizes their parameter sizes, context windows and unique capabilities to help you orient yourself. Tables should contain only succinct information; detailed explanations follow in the model sections.
Model |
Sizes & Architecture |
Context Window |
Notable Features |
Licence |
LLaMA 3 / LLaMA 3.2‑Vision |
8 B and 70 B dense versions; vision‑language variant integrates a vision encoder through cross‑attention. |
8 K–128 K tokens |
Multilingual; long‑context summarization; image captioning. |
Llama Community Licence. |
Mixtral & Ministral |
Mixtral 8×7B and 8×22B are sparse Mixture‑of‑Experts models using grouped‑query and sliding‑window attention; Ministral 8B is an instruction‑tuned 8 B dense model. |
32 K–128 K tokens |
Efficient inference due to MoE; function calling; multilingual support. |
Apache 2.0. |
Gemma 2 |
Compact models at 2 B, 9 B and 27 B parameters optimized for efficient inference across hardware. |
8 K tokens |
Versatile text generation and code assistance; hardware‑agnostic performance. |
Gemma licence (permissive with conditions). |
DBRX |
132 B total parameters with 36 B active via sparse Mixture‑of‑Experts. |
32 K tokens |
Enterprise‑grade performance on reasoning and code tasks; optimised for Retrieval‑Augmented Generation. |
Apache‑style licence. |
DeepSeek‑R1 / V2 |
Chinese MoE model with 671 B total parameters but only 37 B active; features Multi‑Head Latent Attention and Multi‑Token Prediction. |
128 K tokens |
Cost‑efficient training (USD <6 M); high performance on math benchmarks; MIT‑licensed. |
MIT licence. |
Qwen 1.5 |
Family ranging from 0.5 B to 110 B parameters, including MoE variants. |
Up to 32 K tokens |
Supports many languages; integrates with popular frameworks; available in quantized formats. |
Tongyi Qianwen licence. |
Phi‑3 |
Small models at 3.8 B, 7 B and 14 B parameters, plus larger MoE versions (42 B+). |
4 K–16 K tokens |
Designed for on‑device inference; strong at maths and code; curated training data. |
Research/limited commercial licences. |
Falcon 2 |
Two 11 B models: one text‑only and one vision‑language; trained on trillions of tokens. |
8 K tokens |
Multilingual; vision‑to‑language translation; runs on a single GPU. |
Apache 2.0. |
BLOOM |
176 B parameters; dense transformer. |
2 K tokens |
Supports 46 natural languages and 13 programming languages; responsible AI licence. |
BigScience RAIL licence. |
Vicuna‑13B & community models |
13 B parameters; fine‑tuned on user‑shared conversations. |
8 K–16 K tokens |
Achieves >90 % of ChatGPT quality at low cost; demonstrates the power of community fine‑tuning. |
Non‑commercial licence. |
Kimi (K1.5 / K2 / Kimi‑VL) |
MoE models with up to 1 T parameters (Kimi K2 uses 1 T total with 32 B active); Kimi‑VL activates 2.8 B parameters. |
128 K tokens |
Multimodal (text, images & code) tasks; chain‑of‑thought reasoning; reinforcement learning training & long memory; cross‑cultural and fast responses. |
Open‑weight (MIT‑like) licence. |
GPT‑OSS (20B & 120B) |
Two MoE models: 117 B & 21 B total parameters with 5.1 B and 3.6 B active per token. |
128 K tokens |
Why Choose Open‑Source LLMs? Benefits, Challenges and Use Cases
Open‑source LLMs offer control, transparency and flexibility that proprietary APIs rarely match. By downloading model weights, you own the inference pipeline and can fine‑tune the model on domain‑specific data without sending sensitive information to a third‑party service. This autonomy is crucial for regulated industries like healthcare, finance and government, where privacy concerns and data residency requirements preclude cloud‑hosted APIs.
Another benefit is cost efficiency. While training or inference on large models requires GPUs, open weights allow organizations to amortize hardware costs over time and avoid per‑token API fees. Analysts report that open‑source deployments now account for more than half of on‑premises LLM usage. Furthermore, releases of open models have nearly doubled since early 2023, reflecting a flourishing ecosystem.
Open models can be tailored to your unique domain. You can fine‑tune LLaMA 3 on medical texts, quantize Mixtral for mobile devices, or add function‑calling ability to Ministral 8B. The community also publishes optimizations like 4‑bit and 8‑bit quantization that reduce memory footprints without major quality loss. Many models support long‑context extensions (32 K–128 K tokens) and function‑calling interfaces, enabling them to orchestrate external tools or maintain memory in multi‑turn chats.
Despite these advantages, open‑source LLMs require substantial expertise and resources. Running a 70 B parameter model on‑premise may necessitate multi‑GPU servers or clusters. Safety alignment is another challenge; open models may not undergo the same rigorous reinforcement learning and red‑teaming that proprietary models receive. Fine‑tuning them responsibly demands careful curation of training data and the inclusion of safety filters.
Documentation and community support vary. While popular models like LLaMA and Mistral have active communities, others may have sparse documentation. Before committing, evaluate the maturity of the ecosystem, the clarity of the licence, and the ease of integration with your existing stack.
Open‑source LLMs power a variety of applications beyond generic chatbots:
Clarifai’s compute orchestration automates provisioning of GPU/CPU resources across on‑prem and cloud environments, making it easier to deploy open models without over‑provisioning. Model runners allow you to deploy your fine‑tuned weights locally and call them via Clarifai’s API while keeping your data private. A unified model inference API lets you switch between models like LLaMA 3, Mixtral or Gemma 2 with minimal code changes. Safety filters and logging built into Clarifai help mitigate some of the alignment challenges inherent in open models.
Creating a definitive list of the best open‑source LLMs requires a structured approach. We assessed more than 50 sources, including peer‑reviewed papers, technical blog posts, GitHub repositories, conference presentations, and independent benchmark leaderboards. The evaluation criteria included:
Throughout this article, we avoid citing competitor blogs directly. Instead, we reference market research, benchmark results and independent analyses. Each model section includes expert insights and a Quick Summary for readers who skim for answers.
Meta’s LLaMA series has become the standard bearer for open‑source language modelling. LLaMA 3 builds upon its predecessors by expanding both size and capability. Dense versions are available at 8 B and 70 B parameters, offering a balance between quality and computational cost. In May 2025, Meta unveiled LLaMA 3.2‑Vision, which couples a vision encoder to the text model using a cross‑attention mechanism, enabling the model to process images alongside text.
Deploying LLaMA 3 with Clarifai is straightforward thanks to the platform’s model inference API. For long‑context use cases, our compute orchestration automatically provisions the right GPU resources and manages memory to avoid context‑overflow errors. When using the Vision variant, Clarifai’s image pre‑processing and moderation pipeline can sanitize images before they are passed to the model, enhancing safety and compliance.
Why is LLaMA 3 significant? LLaMA 3 is Meta’s flagship open‑source LLM, released in sizes up to 70 B parameters. The models feature 8 K–128 K context windows and multilingual capabilities. The 3.2‑Vision variant adds a vision encoder with cross‑attention, allowing multimodal understanding of images and text. Licensed under the Llama Community Licence, LLaMA 3 forms the backbone of many modern open‑source applications.
Paris‑based Mistral AI changed the open‑source landscape when it released Mistral 7B under the Apache 2.0 licence. Rather than blindly scaling parameters, the team introduced grouped‑query attention (GQA) and sliding‑window attention (SWA), optimizations that share keys and values across queries and limit attention to local windows. This approach reduces memory requirements and improves inference speed.
Building on Mistral 7B, Mixtral 8×7B and Mixtral 8×22B apply a sparse Mixture‑of‑Experts (MoE) architecture. Each model contains eight expert sub‑networks, but only two are activated per token. As a result, the 8×22B variant has 141 B total parameters but only ~39 B active parameters per inference. This architecture offers performance comparable to much larger dense models while keeping inference costs manageable. Mixtral models handle multiple languages and excel at mathematics, coding and reasoning, making them suitable for knowledge‑intensive tasks.
Ministral 8B is an instruction‑tuned version of Mistral’s base model. It incorporates a 128 K token context window and function‑calling capabilities, allowing the model to integrate external tools such as calculators and web search. Ministral’s multilingual proficiency and support for function calling make it an excellent choice for building agents that need to plan tasks, call APIs and generate structured outputs. Its 8 B parameter size also makes it easier to fine‑tune on moderate hardware.
Clarifai’s compute orchestration intelligently assigns GPU resources for MoE models by loading only the active experts, which conserves VRAM and lowers costs. When building agents, integrate Ministral’s function‑calling with Clarifai’s workflow engine to orchestrate external APIs (e.g., retrieving documents, performing calculations). For multilingual deployments, pair Mixtral with Clarifai’s translation models to pre‑process user queries and unify outputs across languages.
What makes Mixtral and Ministral unique? Mixtral models combine grouped‑query attention and sparse Mixture‑of‑Experts, activating only a fraction of their experts per token to deliver high performance with lower compute costs. The instruction‑tuned Ministral 8B adds a 128 K context window and function‑calling capabilities, making it ideal for long‑context tasks and tool‑using agents.
As the AI arms race intensifies, not every organization can afford to run 70 B‑parameter behemoths. Gemma 2 caters to those who need competent models that run efficiently on a variety of hardware. Released by Google, Gemma 2 comes in 2 B, 9 B and 27 B parameter sizes. According to product documentation, the 27 B model can match the performance of models more than twice its size thanks to optimized training and engineering.
Use Clarifai’s model repository to deploy Gemma models quickly. Our compute orchestration chooses the appropriate instance type (CPU, GPU or TPU) based on your throughput requirements. When using Gemma for summarization, pair it with Clarifai’s vector search to retrieve relevant documents, then feed the combined context to the model. This RAG pattern improves factual accuracy while keeping costs in check.
Why pick Gemma 2? Gemma 2 offers 2 B, 9 B and 27 B parameter sizes designed for efficient inference across diverse hardware. With an 8 K context window and strong text generation capabilities, Gemma serves developers who need balanced performance without the overhead of massive models.
DBRX is a sparse Mixture‑of‑Experts model that marries large‑model performance with efficient compute. Built by a research consortium, DBRX contains 132 B total parameters but activates only 36 B per inference. This design allows enterprises to deploy high‑quality models without incurring the costs associated with dense 100+ B‑parameter models.
Clarifai’s compute orchestration is well‑suited for DBRX’s MoE architecture. It loads only the experts needed for the current request and scales horizontally when throughput spikes. When implementing RAG, pair DBRX with Clarifai’s vector search to retrieve relevant passages. Then feed the retrieved documents and user query into the model’s 32 K context window for comprehensive answers.
Why consider DBRX? DBRX is a Mixture‑of‑Experts model with 132 B parameters, activating only 36 B per inference. It supports a 32 K context window, excels at code and reasoning tasks, and offers a commercially friendly licence, making it attractive for enterprise retrieval‑augmented generation systems.
China’s contribution to the open‑source LLM ecosystem has accelerated, with models like DeepSeek‑R1 demonstrating that cost‑efficient training and state‑of‑the‑art performance aren’t mutually exclusive. DeepSeek‑R1 uses a Mixture‑of‑Experts architecture with 671 B total parameters but only 37 B active per query. It incorporates cutting‑edge techniques such as Multi‑Head Latent Attention, Native Sparse Attention and Multi‑Token Prediction.
Clarifai supports deploying DeepSeek models through our model runners. Use compute orchestration to allocate GPU resources based on the active experts and the 128 K context window. DeepSeek’s mathematical abilities make it suitable for educational and financial services; pair it with Clarifai’s document processing modules to extract data from reports and feed them into the model for analysis.
Why do DeepSeek models stand out? DeepSeek‑R1 is a Mixture‑of‑Experts model with 671 B total parameters but only 37 B active per query, delivering strong reasoning and math performance. It features a 128 K context window and novel innovations like Native Sparse Attention and Multi‑Token Prediction. The MIT‑licensed model sets a precedent for cost‑efficient, long‑context LLMs.
Qwen 1.5, developed by a leading cloud provider, offers a family of models with sizes ranging from 0.5 B to 110 B parameters. It includes both dense and MoE variants and supports quantized formats such as Int4, Int8, GPTQ, AWQ and GGUF for efficient deployment.
Clarifai’s model inference API accommodates multiple model sizes, enabling dynamic selection based on input complexity. Use Qwen 1.5 for multilingual chatbots or translation agents and combine it with Clarifai’s speech‑to‑text and text‑to‑speech modules to build voice assistants.
Why consider Qwen 1.5? Qwen 1.5 is a scalable family of open‑source LLMs with sizes from 0.5 B to 110 B parameters. It offers a 32 K context window, supports numerous quantized formats and integrates with popular frameworks. Its strong multilingual performance makes it suitable for global applications.
Phi‑3 represents a new generation of compact LLMs designed for on‑device inference and low‑latency applications. It comes in variants around 3.8 B, 7 B and 14 B parameters, with larger Mixture‑of‑Experts versions rumoured to be in development.
Phi‑3 models fit well within Clarifai’s on‑prem deployment framework. Use our local runners to host the model on dedicated hardware and avoid sending data to the cloud. Combine Phi‑3 with Clarifai’s embedding search to build personal knowledge assistants that run offline.
Why choose Phi‑3? Phi‑3 models pack strong reasoning and coding abilities into compact 3.8 B–14 B parameter sizes suitable for on‑device inference. Their smaller context windows enable low‑latency applications, making them ideal for edge AI and mobile assistants.
The Falcon family began as a high‑performance open‑source alternative to GPT‑3 and evolved into a multimodal powerhouse. Falcon 2 comprises two 11 B models: a text‑only model and a vision‑language model (VLM). Both are released under the Apache 2.0 licence and are independently verified on the Hugging Face leaderboard.
Clarifai’s image processing pipeline works seamlessly with Falcon 2 VLM. You can ingest images through Clarifai, apply moderation and enhancement, then pass the processed images to the model for captioning. For text‑only tasks, Falcon 2’s language model integrates with Clarifai’s RAG workflows and can be combined with our moderation filters to ensure safe outputs.
What sets Falcon 2 apart? Falcon 2 includes text and vision‑language models at 11 B parameters. The VLM converts images to text for applications like document management and e‑commerce. Both models support multiple languages and can run on a single GPU.
BLOOM was born from an unprecedented collaboration among researchers worldwide. It is a dense 176 B‑parameter transformer trained to support 46 natural languages and 13 programming languages. This breadth of languages makes BLOOM a unique resource for academics, nonprofits and communities outside the Anglosphere.
Use Clarifai’s managed model service to access BLOOM without maintaining 176 B parameters locally. Our platform supports streaming inference, which avoids loading the entire model into memory at once. Combine BLOOM with Clarifai’s language identification model to route user queries to the appropriate language pipeline.
Why is BLOOM important? BLOOM is a 176 B‑parameter multilingual model supporting 46 natural languages and 13 programming languages. Released under a Responsible AI licence, it exemplifies collaborative open‑source research and offers broad linguistic coverage.
Community‑driven projects have shown that innovation doesn’t always require corporate backing. Vicuna‑13B is a fine‑tuned model based on the LLaMA architecture. Developers combined approximately 70,000 user‑shared conversations (curated from public data) and trained the model on eight A100 GPUs over a single day. The result is a model that achieves over 90 % of ChatGPT’s quality while costing about USD 300 in cloud compute.
Vicuna sparked a wave of community fine‑tuned models (e.g., Alpaca, Orca, WizardLM) that further improve instruction following, reasoning or safety. These projects underscore the power of open weights, which enable a global community to iterate quickly and share improvements.
Clarifai does not host Vicuna directly due to licensing restrictions. However, you can deploy your own fine‑tuned models on our local runners. Use Clarifai’s moderation filters to mitigate unsafe responses and our analytics dashboard to monitor performance and detect bias.
Why is Vicuna notable? Vicuna‑13B is a community‑fine‑tuned model based on LLaMA. Trained on user‑shared conversations, it achieves 90 % of ChatGPT quality at minimal cost. It highlights the potential of collaborative fine‑tuning but carries non‑commercial licensing and ethical considerations.
The open‑source LLM scene evolves rapidly. Several new models and innovations are poised to shape the next generation of applications:
Clarifai remains committed to supporting new open models as they emerge. Our platform’s pluggable architecture allows you to deploy future LLMs with minimal changes. As multimodality becomes the norm, Clarifai’s suite of vision, speech and text models ensures that you can build end‑to‑end intelligent pipelines. Our tools for orchestration, moderation, monitoring and analytics will help you navigate an increasingly complex landscape.
Selecting the right open‑source LLM depends on your specific use case, resources and risk tolerance. Here are some guidelines:
No matter which model you select, Clarifai’s platform can streamline your journey. Our compute orchestration provisions resources on‑demand; local runners enable private deployment; and our unified inference API allows you to swap models without rewriting code. Built‑in safety filters, moderation and analytics help you deploy LLMs responsibly at scale.
As the open‑source ecosystem continues to evolve—driven by innovations like Native Sparse Attention, cross‑modal retrieval and trillion‑parameter MoE models—developers and organizations must stay informed and agile. With this guide, you’re equipped to navigate the current landscape and make informed decisions about the open‑source LLM that best fits your needs.
Dense models activate all their parameters for every token, resulting in high computational cost but straightforward engineering. MoE models partition parameters into expert networks and activate only a subset per token, dramatically reducing active compute and memory usage. Models like Mixtral, DBRX and DeepSeek demonstrate that MoE architectures can achieve performance comparable to dense models at a fraction of the cost.
The context window determines how many tokens the model can consider at once. Short windows (4 K–8 K) suffice for chatbots and short articles, while longer windows (32 K–128 K) are needed for summarizing books, analyzing legal documents or powering multi‑turn assistants. LLaMA 3.2‑Vision and Ministral 8B support 128 K tokens, whereas Gemma 2 and Falcon 2 are limited to 8 K.
Yes—most open models allow fine‑tuning under their licences. You’ll need GPUs or TPUs, training data and expertise in machine learning. Some models (e.g., Vicuna) were fine‑tuned using open tools like LLaMA‑Factory; others integrate with frameworks like vLLM and AutoAWQ. Clarifai supports fine‑tuning via its platform or by uploading your own fine‑tuned weights for deployment.
Open models may not be fully safety aligned. To mitigate risks, use moderation filters, such as Clarifai’s content moderation API, to screen outputs for harmful or sensitive content. Additionally, implement human feedback loops and audit logs to monitor the model’s behaviour. Pay close attention to the licence terms, which may require you to include attribution or restrict certain uses (e.g., the Llama Community Licence).
Running models on your own infrastructure gives you full control over data flow. Clarifai’s on‑prem deployment solutions let you host models locally, ensuring that sensitive data never leaves your environment. This is particularly important for industries subject to regulations like HIPAA or GDPR.
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