long context benchmark
ComplexFuncBench Leaderboard
ComplexFuncBench evaluates large language models on complex function calling scenarios, including multi-step and constrained tasks across 1,000 samples from five real-world scenarios.
Updated Sep 5, 2026
Models7
Model coverage7
MetricScore
EvidenceB
ComplexFuncBench Ranking
Higher score ranks better on this benchmark.
Sort by
Rank | Model | Score | Percentile | Participants | Evidence | Evaluated |
|---|
| Rank01 | ModelOP | Score66.50% | Percentile100.00% | Participants7 | EvidenceC | Evaluated |
| Rank02 | ModelOP | Score65.50% | Percentile83.33% | Participants7 | EvidenceC | Evaluated |
| Rank03 | ModelAM Nova 2 SonicAmazon | Score65.20% | Percentile66.67% | Participants7 | EvidenceC | Evaluated |
| Rank04 | ModelOP | Score63.00% | Percentile50.00% | Participants7 | EvidenceC | Evaluated |
| Rank05 | ModelOP | Score49.30% | Percentile33.33% | Participants7 | EvidenceC | Evaluated |
| Rank06 | ModelOP | Score17.60% | Percentile16.67% | Participants7 | EvidenceC | Evaluated |
| Rank07 | ModelOP | Score5.70% | Percentile0.00% | Participants7 | EvidenceC | Evaluated |
ComplexFuncBench Highlights
The leading models and scores on this benchmark.
ComplexFuncBench Score Distribution
A closer view of the leading scores on this benchmark.
The Top AI Models for ComplexFuncBench
The first five results on this benchmark, with official price and output speed added where the model identity can be matched.
What is ComplexFuncBench?
What ComplexFuncBench measures and how its scores work.
ComplexFuncBench is a benchmark for evaluating large language models on complex function calling scenarios, including tasks involving long-parameter filling, parameter value reasoning, and contexts up to 128k tokens.
It measures performance on multi-step and constrained function calling tasks using the Score metric, reported as a ratio.
Scores are shown in ratio. This benchmark is not independently verified and has an evidence level of B.
- Family
- ComplexFuncBench
- Modality
- text
- Primary category
- long context
- Score direction
- higher
- LLMBoard eligible
- No
- Evaluation key
- overall
LLM Stats. Benchmark scores retain their original unit. Overall score eligibility is shown separately.
FAQ
Common questions about ComplexFuncBench.
Which model scores highest on ComplexFuncBench?
GPT-4o is currently ranked first with 66.50%.
What are the top three models on ComplexFuncBench?
The current leaders are GPT-4o (66.50%), GPT-4.1 (65.50%), and Nova 2 Sonic (65.20%).
Which ComplexFuncBench model has the lowest official input price?
GPT-4.1 nano has the lowest matched official input price at $0.10 input / $0.40 output per 1M tokens.
Which models are fastest among ComplexFuncBench results?
The fastest matched records are GPT-4.1 mini (467.39 tok/s via OpenAI), GPT-4.1 nano (138.14 tok/s via OpenAI), and GPT-4o (132.00 tok/s via OpenAI).
Does the highest score result prove overall model quality?
No. This benchmark measures one defined capability or task. The overall LLMBoard score uses a separate aggregation across eligible benchmark evidence.