Benchgen

IFEval — Results

RankModelScore
1minicpm5-2b86.7
2lfm2-5-vl-3b82.3
3north-micro-vision-instruct74.9
4qwen3-5-27b0.95
5qwen3-7-plus0.946
6qwen3-6-plus0.943
7qwen3-7-max0.943
8o3-mini0.939
9qwen3-5-122b-a10b0.934
10qwen3-5-397b-a17b0.926
11llama-3-3-70b-instruct0.921
12qwen3-5-35b-a3b0.919
13qwen3-5-9b0.915
14kimi-k2-instruct-09050.898
15kimi-k2-instruct0.898
16qwen3-5-4b0.898
17llama-3-1-nemotron-ultra-253b-v10.894
18qwen3-235b-a22b-instruct-25070.887
19llama-3-1-405b-instruct0.886
20gpt-4-10.874
21deepseek-v30.861
22phi-4-reasoning-plus0.849
23gpt-4-1-mini0.841
24qwen2-5-72b-instruct0.841
25qwq-32b0.839

IFEval

1 phaseActive

Instruction-Following Evaluation — 541 prompts with verifiable constraints (format, length, keyword, case). Metric: prompt-level and instruction-level accuracy.

Overview

IFEval

Category Metric Tasks Saturation

Paper GitHub Dataset

Quick answer: IFEval (Instruction-Following Evaluation) is a benchmark from Google Research (Zhou et al., 2023) that evaluates language models on their ability to follow verifiable, precise instructions. It contains 541 prompts with 25 types of verifiable constraints — such as word count limits, keyword inclusion, format requirements, and capitalization rules. Unlike open-ended instruction benchmarks, IFEval constraints can be checked programmatically, making it deterministic and reproducible.

At a Glance

What it tests: Whether models precisely follow explicit, measurable constraints in their responses — length limits, required keywords, response format (JSON, bullet lists, markdown), forbidden words, and letter-case rules.

Why it matters: IFEval directly measures a model's ability to comply with system-level and user-level formatting requirements — a critical capability for production applications, APIs, and structured output use cases. It complements benchmark suites focused on knowledge or reasoning.

Known limitations: IFEval is increasingly saturated for frontier models (scores above 85–90%). It tests rule-following but not semantic quality of the response. A model could score highly while producing unhelpful content that technically satisfies the constraints.

What IFEval Measures

IFEval is built on 541 prompts covering diverse instruction types. Each prompt includes one or more verifiable constraints drawn from 25 categories including:

  • Format constraints: respond in JSON, use markdown headers, use numbered lists
  • Length constraints: respond in exactly N words, fewer than N sentences
  • Keyword constraints: include specific words, avoid certain words
  • Case constraints: respond in all caps, start each sentence with a capital letter
  • Content constraints: include a specific phrase, answer in a particular language

The benchmark reports two primary metrics:

  1. Prompt-level accuracy: percentage of prompts where ALL constraints are satisfied
  2. Instruction-level accuracy: percentage of individual constraint instances satisfied

Benchmark Specifications

FieldValue
Prompts541
Constraint types25
Primary metricPrompt-level accuracy
Secondary metricInstruction-level accuracy
EvaluationProgrammatic (deterministic)
Created byZhou et al. (Google Research)
PaperarXiv:2311.07911 (Nov 2023)
SaturationHigh — frontier models 85–95%

Frequently Asked Questions

How is IFEval different from IFBench? IFEval uses programmatically verifiable constraints and was created by Google Research (2023). IFBench is a separate benchmark with a broader, more complex set of multi-constraint instruction-following tasks.

What is a good IFEval score? Frontier models (GPT-4o, Claude 3.5+, Gemini 1.5+) score 80–90%+ on prompt-level accuracy. Weaker models often score below 60%. The benchmark is approaching saturation at the frontier.

Does IFEval correlate with real-world instruction following? IFEval correlates with structured output reliability, but it tests only explicit constraint-following, not semantic helpfulness. Models that score well may still fail on implicit or context-dependent instructions.