GLM-5.3 is live. Run Z.ai's latest model on Friendli Model APIs. Try it today ➜
TerraBytes
Available on FriendliAI
Run this model inference on single tenant GPU with unmatched speed and reliability at scale.
Run this model inference with full control and performance in your environment.
Model Details
Model Provider
TerraBytes
Model Tree
Qwen/Qwen2.5-Coder-3B
Input Modalities
Output Modalities
Supported Functionality
VibeThinker-3B is a further exploration of the VibeThinker series at the 3B-parameter scale, focusing on challenging reasoning tasks with clear verification signals, such as mathematics, coding, and STEM. By systematically optimizing the Spectrum-to-Signal Principle (SSP) post-training pipeline introduced in VibeThinker-1.5B, VibeThinker-3B achieves strong performance on AIME, HMMT, IMO-AnswerBench, LiveCodeBench, and recent LeetCode contests, reaching the performance range of top-tier frontier reasoning models, including Qwen3.6 Plus, Gemini 3 Pro, GLM-5, and Kimi K2.5, on verifiable reasoning benchmarks.
Motivated by these observations, we propose the Parametric Compression-Coverage Hypothesis: different capabilities depend on model parameters in fundamentally different ways. Verifiable reasoning is closer to a highly compressible, parameter-dense capability, centered on multi-step reasoning, constraint satisfaction, self-correction, and answer verification. When the task space is sufficiently structured and feedback signals are sufficiently reliable, compact models may also carry near-frontier reasoning capabilities. In contrast, open-domain knowledge, general-purpose dialogue, and long-tail scenario understanding rely more heavily on large-scale parameters to broadly cover facts, concepts, and world knowledge.
From VibeThinker-1.5B to VibeThinker-3B, our goal is not to build a small model that replaces large-scale models, but to examine the real boundaries of small models along specific capability dimensions. With VibeThinker-3B, we aim to show that small models should not be viewed merely as a compromise for reducing deployment costs. For capability domains with clear feedback and verification mechanisms, SLMs emerge as a promising research trajectory toward frontier-level performance that is fundamentally complementary to the traditional parameter scaling paradigm.
📏 In terms of reasoning accuracy relative to model scale, VibeThinker-3B reaches 76.4 on IMO-AnswerBench, a highly challenging benchmark with 400 IMO-level problems, with only 3B parameters, and improves to 80.6 with Claim-Level Reliability Assessment (CLR), a test-time scaling strategy for answer-verifiable reasoning tasks. This demonstrates that a model within a strictly small-model regime can reach the performance range of substantially larger models, such as DeepSeek V3.2 (78.3, 671B), GLM-5 (82.5, 744B), and Kimi K2.5 (81.8, 1T).
💡 VibeThinker-3B achieves strong results across mathematics, coding, knowledge, and instruction-following benchmarks.
🔁 VibeThinker-3B achieves competitive results against first-tier reasoning models and reaches the performance range of top-tier systems on several verifiable reasoning benchmarks.
🏆 To further test the model's out-of-distribution performance, we evaluate VibeThinker-3B on recent unseen LeetCode weekly and biweekly contests (Python) from Apr. 25 to May 31, 2026. VibeThinker-3B passes 123/128 first-attempt submissions, corresponding to a 96.1% acceptance rate.
VibeThinker-3B follows the Spectrum-to-Signal Principle (SSP) introduced in VibeThinker-1.5B. The SFT stage constructs a broad spectrum of valid reasoning trajectories, while the RL stage amplifies correct reasoning signals using verifiable rewards.
The training pipeline contains the following stages:
Curriculum-based two-stage SFT
Multi-domain Reasoning RL
Offline Self-Distillation
We recommend using VibeThinker-3B for competitive-style math, coding, STEM reasoning, and other tasks where the target answer can be verified. For broad open-domain knowledge tasks, larger general-purpose models may still be more suitable.
For benchmark-style evaluation, the technical report uses vLLM with:
temperature=1.0top_p=0.95top_k=-1Required: transformers>=4.54.0
Recommended for better inference performance: vLLM==0.10.1 or SGLang>=0.4.9.post6
python
from transformers import AutoModelForCausalLM, AutoTokenizer, GenerationConfig class VibeThinker: def __init__(self, model_path): self.model_path = model_path self.model = AutoModelForCausalLM.from_pretrained( self.model_path, low_cpu_mem_usage=True, torch_dtype="bfloat16", device_map="auto", ) self.tokenizer = AutoTokenizer.from_pretrained( self.model_path, trust_remote_code=True, ) def infer_text(self, prompt): messages = [{"role": "user", "content": prompt}] text = self.tokenizer.apply_chat_template( messages, tokenize=False, add_generation_prompt=True, ) model_inputs = self.tokenizer([text], return_tensors="pt").to(self.model.device) generation_config = dict( max_new_tokens=102400, do_sample=True, temperature=1.0, top_p=0.95, top_k=None, ) generated_ids = self.model.generate( **model_inputs, generation_config=GenerationConfig(**generation_config), ) generated_ids = [ output_ids[len(input_ids):] for input_ids, output_ids in zip(model_inputs.input_ids, generated_ids) ] return self.tokenizer.batch_decode( generated_ids, skip_special_tokens=True, )[0] if __name__ == "__main__": model = VibeThinker("WeiboAI/VibeThinker-3B") prompt = "Your Prompt" print(model.infer_text(prompt))The model repository is licensed under the MIT License.
If you use VibeThinker-3B in your research or product, please cite:
bibtex
@misc{xu2026vibethinker3bexploringfrontierverifiable, title={VibeThinker-3B: Exploring the Frontier of Verifiable Reasoning in Small Language Models}, author={Sen Xu and Shixi Liu and Wei Wang and Jixin Min and Yingwei Dai and Zhibin Yin and Yirong Chen and Xin Zhou and Junlin Zhang}, year={2026}, eprint={2606.16140}, archivePrefix={arXiv}, primaryClass={cs.AI}, url={https://arxiv.org/abs/2606.16140}, }@misc{xu2026vibethinker3bexploringfrontierverifiable, title={VibeThinker-3B: Exploring the Frontier of Verifiable Reasoning in Small Language Models}, author={Sen Xu and Shixi Liu and Wei Wang and Jixin Min and Yingwei Dai and Zhibin Yin and Yirong Chen and Xin Zhou and Junlin Zhang}, year={2026}, eprint={2606.16140}, archivePrefix={arXiv}, primaryClass={cs.AI}, url={https://arxiv.org/abs/2606.16140}, }Instruct RL