What are the Fastest Open Source LLMs?
The fastest open source Large Language Models are AI systems optimized for rapid inference and efficient resource utilization while maintaining high-quality outputs. These models typically feature smaller parameter counts (7B-9B), optimized architectures, and advanced training techniques that enable lightning-fast text generation, reasoning, and conversation capabilities. They democratize access to high-speed AI by allowing developers to deploy powerful language models with minimal computational overhead, making them ideal for real-time applications, edge computing, and resource-constrained environments where speed is paramount.
Qwen/Qwen3-8B
Qwen3-8B is the latest large language model in the Qwen series with 8.2B parameters. This model uniquely supports seamless switching between thinking mode (for complex logical reasoning, math, and coding) and non-thinking mode (for efficient, general-purpose dialogue). It demonstrates significantly enhanced reasoning capabilities, surpassing previous QwQ and Qwen2.5 instruct models in mathematics, code generation, and commonsense logical reasoning.
Qwen3-8B: Dual-Mode Speed Champion
Qwen3-8B is the latest large language model in the Qwen series with 8.2B parameters. This model uniquely supports seamless switching between thinking mode (for complex logical reasoning, math, and coding) and non-thinking mode (for efficient, general-purpose dialogue). It demonstrates significantly enhanced reasoning capabilities, surpassing previous QwQ and Qwen2.5 instruct models in mathematics, code generation, and commonsense logical reasoning. The model excels in human preference alignment for creative writing, role-playing, and multi-turn dialogues. Additionally, it supports over 100 languages and dialects with strong multilingual instruction following and translation capabilities.
Pros
- Seamless switching between thinking and non-thinking modes.
- Enhanced reasoning capabilities in math and coding.
- Supports over 100 languages and dialects.
Cons
- Newer model with limited real-world deployment data.
- May require optimization for specific use cases.
Why We Love It
- It delivers the perfect balance of speed and intelligence with dual-mode operation, making it incredibly versatile for both fast dialogue and complex reasoning tasks.
meta-llama/Meta-Llama-3.1-8B-Instruct
Meta Llama 3.1 is a family of multilingual large language models developed by Meta, featuring pretrained and instruction-tuned variants. This 8B instruction-tuned model is optimized for multilingual dialogue use cases and outperforms many available open-source and closed chat models on common industry benchmarks. The model was trained on over 15 trillion tokens of publicly available data.
Meta-Llama-3.1-8B-Instruct: Industry-Leading Speed
Meta Llama 3.1 is a family of multilingual large language models developed by Meta, featuring pretrained and instruction-tuned variants in 8B, 70B, and 405B parameter sizes. This 8B instruction-tuned model is optimized for multilingual dialogue use cases and outperforms many available open-source and closed chat models on common industry benchmarks. The model was trained on over 15 trillion tokens of publicly available data, using techniques like supervised fine-tuning and reinforcement learning with human feedback to enhance helpfulness and safety. Llama 3.1 supports text and code generation, with a knowledge cutoff of December 2023.
Pros
- Outperforms many open-source and closed models on benchmarks.
- Trained on over 15 trillion tokens of data.
- Optimized for multilingual dialogue use cases.
Cons
- Knowledge cutoff limited to December 2023.
- Requires careful prompt engineering for optimal results.
Why We Love It
- It combines Meta's cutting-edge research with proven benchmark performance, delivering exceptional speed without compromising on quality or safety.
Qwen/Qwen2.5-VL-7B-Instruct
Qwen2.5-VL is a new member of the Qwen series, equipped with powerful visual comprehension capabilities. It can analyze text, charts, and layouts within images, understand long videos, and capture events. The model has been optimized for dynamic resolution and frame rate training in video understanding, and has improved the efficiency of the visual encoder.
Qwen2.5-VL-7B-Instruct: Lightning-Fast Vision-Language Model
Qwen2.5-VL is a new member of the Qwen series, equipped with powerful visual comprehension capabilities. It can analyze text, charts, and layouts within images, understand long videos, and capture events. It is capable of reasoning, manipulating tools, supporting multi-format object localization, and generating structured outputs. The model has been optimized for dynamic resolution and frame rate training in video understanding, and has improved the efficiency of the visual encoder, making it one of the fastest vision-language models available.
Pros
- Powerful visual comprehension with optimized encoder efficiency.
- Supports dynamic resolution and frame rate training.
- Multi-format object localization capabilities.
Cons
- Specialized for vision tasks, less optimal for text-only use.
- Requires visual input processing which may add latency.
Why We Love It
- It's the fastest vision-language model in our lineup, combining lightning-speed inference with powerful multimodal capabilities in a compact 7B parameter package.
Fastest LLM Comparison
In this table, we compare 2025's fastest open source LLMs, each optimized for different speed requirements. For versatile dual-mode operation, Qwen3-8B offers unmatched flexibility. For benchmark-leading multilingual dialogue, Meta-Llama-3.1-8B-Instruct delivers industry-standard performance, while Qwen2.5-VL-7B-Instruct prioritizes ultra-fast vision-language processing. This side-by-side view helps you choose the right model for your specific speed and functionality requirements.
| Number | Model | Developer | Parameters | SiliconFlow Pricing | Core Strength |
|---|---|---|---|---|---|
| 1 | Qwen/Qwen3-8B | Qwen3 | 8B | $0.06/M Tokens | Dual-mode operation flexibility |
| 2 | meta-llama/Meta-Llama-3.1-8B-Instruct | meta-llama | 8B | $0.06/M Tokens | Industry-leading benchmarks |
| 3 | Qwen/Qwen2.5-VL-7B-Instruct | Qwen | 7B | $0.05/M Tokens | Fastest vision-language processing |
Frequently Asked Questions
Our top three fastest open source LLMs for 2025 are Qwen/Qwen3-8B, meta-llama/Meta-Llama-3.1-8B-Instruct, and Qwen/Qwen2.5-VL-7B-Instruct. Each of these models stood out for their exceptional inference speed, efficiency, and unique approach to delivering fast, high-quality outputs with minimal computational overhead.
For maximum versatility with speed control, Qwen3-8B's dual-mode operation is ideal. For consistently fast multilingual dialogue, Meta-Llama-3.1-8B-Instruct excels with proven benchmark performance. For ultra-fast vision-language tasks, Qwen2.5-VL-7B-Instruct offers the smallest footprint with powerful multimodal capabilities.