AceBench
Models call tools from 4,538 Chinese and English APIs in normal, special, and multi-turn agent cases. Answers are checked without LLM judges or live APIs.
In the authors’ words
Large Language Models (LLMs) have demonstrated significant potential in decision-making and reasoning, particularly when integrated with various tools to effectively solve complex problems. However, existing benchmarks for evaluating LLMs' tool usage face several limitations: (1) limited evaluation scenarios, often lacking assessments in real multi-turn dialogue contexts; (2) narrow evaluation dimensions, with insufficient detailed assessments of how LLMs use tools; and (3) reliance on LLMs or real API executions for evaluation, which introduces significant overhead. To address these challenges, we introduce ACEBench, a comprehensive benchmark for assessing tool usage in LLMs. ACEBench categorizes data into three primary types based on evaluation methodology: Normal, Special, and Agent. "Normal" evaluates tool usage in basic scenarios; "Special" evaluates tool usage in situations with ambiguous or incomplete instructions; "Agent" evaluates tool usage through multi-agent interactions to simulate real-world, multi-turn dialogues. We conducted extensive experiments using ACEBench, analyzing various LLMs in-depth and providing a more granular examination of error causes across different data types.
- Level
- Everyday Most adults, without training
- Scored
- Checked automatically A program checks the result against an answer key, unit tests or the expected final state.
- Answers
- Short answer A number, word or short string matched to a key.
GPT-4o leads with 85.4% among models released by Jul 2025
Best score per entry from the benchmark's own leaderboard, read on 2 Nov 2026. Where a model ran with several settings or harnesses, we keep its best. Names in gray aren't in our model list: fine-tunes, agent systems, products and older models. They don't count toward leaders.
The newest model with a score here came out in Jul 2025, and nobody has tested a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:
- GPT-6 Astra
- Claude Opus 5.5
- GPT-6.1 Terra
- GPT-6.1 Sol
- and 16 more
- 85.4 GPT-4o
- 82.2 Kimi K2
- 80.6
Gemini 2.5 Pro
- 79.6
Qwen2.5-Coder-32B-Instruct
- 78.4 Qwen-Max
- 74.8
DeepSeek-V3
- 74.7
Qwen2.5-72B
- 72.5 GPT-4o mini
- 72.2 ToolACE-2.5-Llama-3.1-8B
- 70.7
Gemini 1.5 Pro
- 68.9 Claude 3.5 Sonnet
- 60.4
Llama 3.1-70B
- 59.4 Doubao-Pro-32K
- 54.8
Qwen2.5-7B
- 49.5 DeepSeek-Coder-V2-Lite-Instruct
- 48.9
Qwen2.5-Coder (7B)
- 45.7 Watt-Tool-8B
- 42.9 Hammer2.1-7B
- 33.4
Llama 3.1-8B
- 32.0
Phi-3-mini-128k-instruct
- 21.6 xLAM-7b-r
- 19.6
Llama 3.2 3B
- 11.3 Hammer2.1-3B
- 1 GPT-4o Nov 2024 85.4%
- 2 Kimi K2 Jul 2025 82.2%
- 3
Gemini 2.5 Pro May 2025 80.6%
- 4
Qwen2.5-Coder-32B-Instruct 79.6%
- 5 Qwen-Max 78.4%
- 6
DeepSeek-V3 74.8%
- 7
Qwen2.5-72B 74.7%
- 8 GPT-4o mini 72.5%
- 9 ToolACE-2.5-Llama-3.1-8B 72.2%
- 10
Gemini 1.5 Pro Sep 2024 70.7%
- 11 Claude 3.5 Sonnet 68.9%
- 12
Llama 3.1-70B 60.4%
- 13 Doubao-Pro-32K 59.4%
- 14
Qwen2.5-7B 54.8%
- 15 DeepSeek-Coder-V2-Lite-Instruct 49.5%
- 16
Qwen2.5-Coder (7B) 48.9%
- 17 Watt-Tool-8B 45.7%
- 18 Hammer2.1-7B 42.9%
- 19
Llama 3.1-8B 33.4%
- 20
Phi-3-mini-128k-instruct 32%
- 21 xLAM-7b-r 21.6%
- 22
Llama 3.2 3B 19.6%
- 23 Hammer2.1-3B 11.3%
| # | Entry | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | GPT-4o Nov 2024 | 85.4% | Nov 2024 | Official leaderboard | |
| 2 | Kimi K2 Jul 2025 | 82.2% | Jul 2025 | Official leaderboard | |
| 3 | | 80.6% | May 2025 | Official leaderboard | |
| 4 | | 79.6% | Nov 2024 | Official leaderboard | |
| 5 | Qwen-Max | 78.4% | Jan 2025 | Official leaderboard | |
| 6 | | 74.8% | Dec 2024 | Official leaderboard | |
| 7 | | 74.7% | Sep 2024 | Official leaderboard | |
| 8 | GPT-4o mini | 72.5% | Jul 2024 | Official leaderboard | |
| 9 | ToolACE-2.5-Llama-3.1-8B | 72.2% | Jan 2025 | Official leaderboard | |
| 10 | | 70.7% | Sep 2024 | Official leaderboard | |
| 11 | Claude 3.5 Sonnet | 68.9% | Jun 2024 | Official leaderboard | |
| 12 | | 60.4% | Jul 2024 | Official leaderboard | |
| 13 | Doubao-Pro-32K | 59.4% | Jan 2025 | Official leaderboard | |
| 14 | | 54.8% | Sep 2024 | Official leaderboard | |
| 15 | DeepSeek-Coder-V2-Lite-Instruct | 49.5% | Jun 2024 | Official leaderboard | |
| 16 | | 48.9% | Sep 2024 | Official leaderboard | |
| 17 | Watt-Tool-8B | 45.7% | Jan 2025 | Official leaderboard | |
| 18 | Hammer2.1-7B | 42.9% | Jan 2025 | Official leaderboard | |
| 19 | | 33.4% | Jul 2024 | Official leaderboard | |
| 20 | | 32% | Apr 2024 | Official leaderboard | |
| 21 | xLAM-7b-r | 21.6% | Jan 2025 | Official leaderboard | |
| 22 | | 19.6% | Sep 2024 | Official leaderboard | |
| 23 | Hammer2.1-3B | 11.3% | Jan 2025 | Official leaderboard |
Labs report scores for 3 models in their cards. We plot every source in the charts below.
Number one over time
Lab claims count from the day the card came out, independent runs from the model’s release. We draw one row each for the benchmark’s own leaderboard and what labs claim in their cards.
The best score passed 85% in Nov 2024
All the scores we have, one dot each, so a model tested at several settings appears more than once.
Labs headline it less often now, last in Feb 2026
Launch posts from every lab that has listed it, one tick per post. Tall colored ticks include it, and short gray ones leave it out.
| Date | Launch post | Score | As the post writes it |
|---|---|---|---|
| 6 Feb 2026 | 88.7 | Mean of ACEBench-en 87.70 / ACEBench-zh 89.60 | |
| 29 Aug 2025 | 76.1 | AceBench(acc) | |
| 11 Jul 2025 | Kimi K2 | 76.5 | AceBench, Acc |
3 system cards report it, from 3 labs
Besides launch posts, we read the system cards, model cards and technical reports labs publish with a release. They report far more, including safety and frontier-risk tests.
| Date | Document | Score | As the document writes it | Section |
|---|---|---|---|---|
| 4 Feb 2026 | | ACEBench-en 87.70, ACEBench-zh 89.60, no overall score (Table 2) | Capabilities | |
| 1 Sep 2025 | | 76.1 | AceBench (acc), direct prompting (Table 3) | Capabilities |
| 21 Jul 2025 | Kimi K2 technical report | 76.5 | AceBench (Acc.), ACEBench English overall (Table 3) | Capabilities |
More in Tool use
- AutomationBench In use Agent completes end-to-end business workflows inside a simulated company exposing dozens of REST APIs. Graded on resulting state.
Gemini 4 Carbon 53.9%
- MCP Atlas In use Multi-step workflows over real MCP servers. Scores tool-use competency on realistic tasks.
Muse Spark 1.1 88.1%
- BFCL V4 In use Models call functions and tools, including multi-turn agentic tasks with web search and memory. Checked against expected calls and outcomes.
Qwen3.7-Max 75%
- τ³-bench Banking In use Agents act as banking customer-service reps over many turns with a simulated user, following policy. Pass^1 on the final database state.
Qwen 3.8 Max 55.1%
- Claw-Eval In use 300 human-verified agent tasks (service orchestration, multimodal, multi-turn dialogue) audited via traces and snapshots. Rubric scores with Pass^3 consistency. Claude Sonnet 4.6 81.4%
- DeepSearchQA In use Questions that need multi-step search and synthesis. Final answers graded against references. Kimi K3 95%