Benchmark Almanac

COLLIE

GPT-5 99% leads since August 2025
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Models generate text that meets compositional constraints at word, sentence, paragraph, and passage level. Scored by the share passing automatic constraint checks.

Made by
Princeton NLP
Released
July 2023
Kind
Following precise instructions
Level
Everyday
Scored
Checked automatically
Answers
Open-ended
Tasks
All public
Strongest model tested
GPT-5 #70 on the capability index
Last in a launch post
May 2026, dropped after it saturated
Last model added
May 2026

In the authors’ words

Text generation under constraints have seen increasing interests in natural language processing, especially with the rapidly improving capabilities of large language models. However, existing benchmarks for constrained generation usually focus on fixed constraint types (e.g.,generate a sentence containing certain words) that have proved to be easy for state-of-the-art models like GPT-4. We present COLLIE, a grammar-based framework that allows the specification of rich, compositional constraints with diverse generation levels (word, sentence, paragraph, passage) and modeling challenges (e.g.,language understanding, logical reasoning, counting, semantic planning). We also develop tools for automatic extraction of task instances given a constraint structure and a raw text corpus. Using COLLIE, we compile the COLLIE-v1 dataset with 2080 instances comprising 13 constraint structures. We perform systematic experiments across five state-of-the-art instruction-tuned language models and analyze their performances to reveal shortcomings. COLLIE is designed to be extensible and lightweight, and we hope the community finds it useful to develop more complex constraints and evaluations in the future.

Abstract of COLLIE: Systematic Construction of Constrained Text Generation Tasks (arXiv:2307.08689, CC0)
12
Models scored in lab cards
12
Launch posts list it, from 4 labs
5
System cards report it, from 2 labs

GPT-5 leads with 99% among models released by April 2026

Best score per model as labs report them in their own cards. Labs pick their own settings, so these compare less cleanly than independent runs.

The newest model with a score here came out in April 2026, and nobody has reported a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:

  1. 1 GPT-5 99%
  2. 2 GPT-5 mini 98.5%
  3. 3 GPT-5 nano 96.9%
  4. 4 Mistral Medium 3.5 95.8%
  5. 5 Seed2.0 Pro 93.9%
  6. 6 Seed-Thinking-v1.5 73.1%
  7. 7 Seed1.8 72.6%
  8. 8 Mistral Small 4 62.9%
  9. 9 LongCat-Flash-Chat 57.1%
  10. 10 GPT-4.1 mini 54.6%
  11. 11 LongCat-Flash-Omni 45.7%
  12. 12 GPT-4.1 nano 42.5%

Source: Labs’ model cards

#ModelScoreSettingDateSource
1 GPT-5 99% Aug 2025 Lab model card
2 GPT-5 mini 98.5% Aug 2025 Lab model card
3 GPT-5 nano 96.9% Aug 2025 Lab model card
4 Mistral Medium 3.5 95.8% May 2026 Lab model card
5 Seed2.0 Pro 93.9% Feb 2026 Lab model card
6 Seed-Thinking-v1.5 73.1% Apr 2025 Lab model card
7 Seed1.8 72.6% Dec 2025 Lab model card
8 Mistral Small 4 62.9% Mar 2026 Lab model card
9 LongCat-Flash-Chat 57.1% Aug 2025 Lab model card
10 GPT-4.1 mini 54.6% Apr 2025 Lab model card
11 LongCat-Flash-Omni 45.7% Oct 2025 Lab model card
12 GPT-4.1 nano 42.5% Apr 2025 Lab model card

2 models have held number one in labs’ own numbers since its release in July 2023

Lab claims count from the day the card came out, independent runs from the model’s release.

ByteDance Seed OpenAI
Lab claims Passed 85% in Aug 2025, by GPT-5
GPT-5 99%

Source: Labs’ model cards

OpenAI’s own number for GPT-5 passed 85% in August 2025

All the scores we have, one dot each, so a model tested at several settings appears more than once.

Reported by the lab in its model card Best so far
0% 20% 40% 60% 80% 100% 2025 2026 Near the ceiling (85%) GPT-5 Seed-Thinking-v1.5 0% 20% 40% 60% 80% 100% 2025 2026 Near the ceiling (85%) GPT-5 Seed-Thinking-v1.5

Source: Labs’ model cards

Labs headline it less often now, last in May 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.

ByteDance Seed
OpenAI
Meituan
Mistral AI
DateLaunch postScoreAs the post writes it
May 22, 2026 Mistral Medium 3.5 95.8 Collie
Mar 16, 2026 Mistral Small 4 62.9 Collie [Mistral Small 4 - High]
Feb 14, 2026 Seed2.0 Pro 93.9 COLLIE
Dec 18, 2025 Seed1.8 72.6 Collie-Hard
Oct 31, 2025 LongCat-Flash-Omni 45.7 COLLIE(acc)
Aug 29, 2025 LongCat-Flash-Chat 57.1 COLLIE(acc)
Aug 7, 2025 GPT-5 nano 96.9 COLLIE
Aug 7, 2025 GPT-5 mini 98.5 COLLIE
Aug 7, 2025 GPT-5 99 COLLIE Instruction-following in freeform writing
Apr 14, 2025 GPT-4.1 nano 42.5 COLLIE
Apr 14, 2025 GPT-4.1 mini 54.6 COLLIE
Apr 10, 2025 Seed-Thinking-v1.5 73.1 Collie

5 system cards report it, from 2 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.

DateDocumentScoreAs the document writes itSection
Mar 21, 2026 Seed1.8 model card 72.6 Collie-Hard (Table 1) Capabilities
Feb 14, 2026 Seed2.0 Pro model card 93.9 COLLIE (Table 3) Capabilities
Oct 31, 2025 LongCat-Flash-Omni technical report 45.7 COLLIE (acc) (Table 13) Capabilities
Sep 1, 2025 LongCat-Flash-Chat technical report 57.1 COLLIE (acc) (Table 3) Capabilities
Apr 10, 2025 Seed-Thinking-v1.5 technical report 73.1 Collie (Table 2) Capabilities

More in Instructions and chat

All 81 in Instructions and chat
  • IFEval In use Models answer about 500 prompts containing verifiable instructions such as word limits or required keywords. Code checks each instruction for strict and loose accuracy. Gemma 4 31B IT 98.9%
  • IFBench In use 58 new out-of-domain verifiable output constraints. Scored by programmatic constraint checks (strict or loose). Nemotron-Cascade 2 30B-A3B 82.9%
  • MultiChallenge In use Multi-turn conversations testing instruction retention, inference memory, versioned editing and self-coherence. Graded by LLM judge with rubrics. GPT-6.1 Sol 82%
  • Multi-IF In use Models follow verifiable instructions over three-turn conversations in eight languages, extending IFEval. Scored by instruction accuracy at each turn. LFM3-1.7B 89.1%
  • AdvancedIF In use Models respond to over 1,600 prompts with complex, multi-turn, and system-level instructions. A judge model checks each response against expert-written rubrics. MAI-Thinking-1 85%
  • IFStruct In use Models generate JSON or YAML that must follow a requested schema and phrasing constraints, without constrained decoding. A response passes only if every structural constraint holds. Gemma 4 31B IT 95.9%