ukisai/Swift-Qwen3.8-27b

VISIONPricing:Input $0.4 / Cached $0.15 / Output $3Concurrent Unit Cost:2Model Size:27BQuant:FP8Context Size:32kTool Calling:SupportedPublished:Sep 8, 2026License:otherArchitecture:Transformer0.5K Featherless Exclusive Cold

Swift-Qwen3.8-27B is a 27 billion parameter language model developed by UkisAI, derived from Qwen3.8-27B. This model is optimized for reasoning efficiency, using 58.3% fewer "thinking tokens" while maintaining near-identical performance (less than 1% loss) and achieving a 1.95x speed-up on various tasks. It is particularly suited for applications requiring faster inference and reduced computational overhead in reasoning-intensive scenarios, including general reasoning, mathematics, multimodal tasks, and agentic coding.

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Overview

Swift-Qwen3.8-27B is a 27 billion parameter model developed by UkisAI, built upon the Qwen3.8-27B architecture. Its primary innovation lies in its reasoning efficiency, achieved by fine-tuning to penalize specific "reasoning-marker tokens" that trigger overthinking in the base Qwen model. This approach results in significantly shorter reasoning traces and fewer overthinking errors.

Key Capabilities & Differentiators

  • Enhanced Efficiency: Swift-Qwen3.8-27B uses 58.3% fewer thinking tokens compared to its base model, leading to a 1.95x speed-up across various tasks.
  • Maintained Performance: Despite the token reduction, the model retains near-identical performance with less than 1% loss on evaluated benchmarks.
  • Consistent Savings: Thinking-token savings persist across different reasoning_effort settings (xhigh, medium, low) of the Qwen3.8 model.
  • Quantization Benefits: The model is designed for quantized deployment, retaining token savings in INT4 evaluations and, for AIME 2026, matching or improving accuracy while reducing output-cap failures by 31-33%.
  • Broad Application: Benchmarks demonstrate its efficiency across general reasoning (GPQA-Diamond, MMLU-Pro, C-Eval, IFBench), mathematics (AIME 2026, HMMT), multimodal tasks (ERQA), and agentic coding (Terminal-Bench 2.1, LiveCodeBench v6).

When to Use This Model

This model is ideal for use cases where:

  • Inference speed is critical for reasoning-heavy tasks.
  • Computational resources are constrained, benefiting from reduced token usage.
  • Quantized deployment is desired for lower memory footprints.
  • Applications involve general reasoning, mathematical problem-solving, multimodal understanding, or agentic code generation where efficiency is paramount.