GPT-5 Nano - NC Bench

openai/gpt-5-nano

GPT-5 Nano

via OpenRouter

Release Date

Aug 7th, 2025

Parameters

–

Context Size

400k

Benchmark Cost

$0.99

Speed

87.0 tok/s

Creative writing

52.58%

Rule following

84.62%

Utility

83.31%

Mathematics

100.00%

Tooling

89.73%

Language

75.30%

Logic

86.00%

Codex Violation Detection

Detects factual inconsistencies between a story bible and prose passages. The model must output structured XML identifying each violation with paragraph number and substring.

Scenario	Run 1	Run 2	Run 3	Run 4	Run 5	Run 6	Run 7	Run 8	Run 9	Run 10	Total
matrix
Large codex (40 entries), long passage (1,019 words) 0-shot ToolingUtilityLogicRule following	84%	82%	82%	82%	81%	78%	77%	76%	69%	69%	78%
Large codex (40 entries), short passage (165 words) 0-shot ToolingUtilityLogicRule following	92%	92%	90%	89%	88%	87%	86%	84%	3%	0%	71%
Small codex (7 entries), long passage (734 words) 0-shot ToolingUtilityLogicRule following	91%	91%	89%	87%	87%	82%	82%	81%	81%	78%	85%
Small codex (7 entries), short passage (165 words) 0-shot ToolingUtilityLogicRule following	97%	97%	93%	93%	93%	93%	90%	90%	90%	90%	93%
tiers
5 codex entries 0-shot ToolingUtilityLogicRule following	100%	100%	100%	93%	93%	93%	93%	75%	75%	3%	83%
10 codex entries 0-shot ToolingUtilityLogicRule following	100%	100%	94%	86%	86%	86%	86%	86%	86%	86%	90%
20 codex entries 0-shot ToolingUtilityLogicRule following	97%	94%	94%	94%	89%	89%	88%	86%	85%	85%	90%
40 codex entries 0-shot ToolingUtilityLogicRule following	97%	95%	93%	87%	84%	84%	84%	84%	83%	75%	87%
84.49%

Data extraction

Extract key details from a given block of text.

Scenario	Run 1	Run 2	Run 3	Run 4	Run 5	Run 6	Run 7	Run 8	Run 9	Run 10	Total
All valid emails 0-shot Utility	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
Contextual pronoun 0-shot Utility	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
Fruits excluding citrus 0-shot Utility	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
Future event time 0-shot UtilityLogic	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
Guess the pet 0-shot UtilityLogic	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
Highest-rated movie 0-shot Utility	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
Indirect birth year 0-shot UtilityMathematicsLogic	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
What instrument does Lucy play? 0-shot UtilityLogic	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
What's the color of the car? 0-shot UtilityLogic	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
What's the correct time? 0-shot UtilityLogic	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%
Who's the sister? 0-shot UtilityLogic	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
Who's the tallest? 0-shot UtilityLogic	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
91.67%

Dialogue tags

Various tasks related to dialogue tags in text.

Scenario	Run 1	Run 2	Run 3	Run 4	Run 5	Run 6	Run 7	Run 8	Run 9	Run 10	Total
dialogue-200
Write 200 words with 10% dialogue 0-shot Creative writingRule following	100%	100%	100%	100%	100%	100%	100%	100%	100%	68%	97%
Write 200 words with 50% dialogue 0-shot Creative writingRule following	100%	100%	96%	50%	50%	50%	50%	50%	50%	50%	65%
Write 200 words with 90% dialogue 0-shot Creative writingRule following	98%	98%	98%	50%	50%	50%	50%	50%	50%	13%	61%
dialogue-500
Write 500 words with 30% dialogue 0-shot Creative writingRule following	74%	50%	49%	27%	20%	5%	2%	0%	0%	0%	23%
Write 500 words with 50% dialogue 0-shot Creative writingRule following	73%	71%	50%	50%	25%	0%	0%	0%	0%	0%	27%
Write 500 words with 70% dialogue 0-shot Creative writingRule following	50%	0%	0%	0%	0%	0%	0%	0%	0%	0%	5%
Ungrouped
Write unattributed dialogue 0-shot Creative writingRule following	100%	100%	100%	100%	100%	100%	100%	100%	100%	14%	91%
52.58%

Language Comprehension

Does the model understand more than just English?

Scenario	Run 1	Run 2	Run 3	Run 4	Run 5	Total
Asking for directions (Dutch) 0-shot Language	100%	100%	100%	100%	0%	80%
Asking for directions (German) 0-shot Language	100%	100%	0%	0%	0%	40%
Friend got new kittens (German) 0-shot Language	0%	0%	0%	0%	0%	0%
Friend got new kittens (Tagalog) 0-shot Language	100%	100%	100%	100%	100%	100%
55.00%

Language Writing

Can the model generate text in different languages?

Scenario	Run 1	Run 2	Run 3	Run 4	Run 5	Total
Character dialogue (French) in a story 0-shot Language	100%	100%	93%	89%	86%	93%
Character dialogue (German) in a story 0-shot Language	100%	90%	80%	78%	73%	84%
Character dialogue (Hindi) in a story 0-shot Language	100%	100%	100%	100%	100%	100%
Character dialogue (Italian) in a story 0-shot Language	100%	100%	83%	83%	81%	90%
Character dialogue (Spanish) in a story 0-shot Language	100%	92%	91%	88%	82%	91%
91.54%

N-Length Sentences

Write sentences with exactly N words

Scenario	Run 1	Run 2	Run 3	Run 4	Run 5	Run 6	Run 7	Run 8	Run 9	Run 10	Total
Write sentences with 5 words each 0-shot Rule following	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
Write sentences with 10 words each 0-shot Rule following	100%	100%	100%	100%	100%	100%	100%	100%	100%	97%	100%
Write sentences with 20 words each 0-shot Rule following	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
99.91%

Novel outline

Handle questions about the outline of a novel in various formats

Scenario	Run 1	Run 2	Run 3	Run 4	Run 5	Run 6	Run 7	Run 8	Run 9	Run 10	Total
outline-count
Count acts 0-shot ToolingUtility	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
Count chapters 0-shot ToolingUtility	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
Count scenes 0-shot ToolingUtility	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
pov-count
Count point of views for Jack and Olivia 0-shot ToolingUtility	100%	100%	100%	100%	50%	50%	50%	50%	50%	50%	70%
Count point of views for Jack Harper 0-shot ToolingUtility	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
Count point of views for Olivia 0-shot ToolingUtility	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
95.00%

Tool usage within Novelcrafter

Output messages that are related to tool usage within Novelcrafter

Scenario	Run 1	Run 2	Run 3	Run 4	Run 5	Run 6	Run 7	Run 8	Run 9	Run 10	Total
Create alternate prose sections 0-shot ToolingUtility	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
100.00%

Voice/dialogue sheets

Extract dialogue from given text as voice sheets.

Scenario	Run 1	Run 2	Run 3	Run 4	Run 5	Run 6	Run 7	Run 8	Run 9	Run 10	Total
Multiple speakers 0-shot Utility	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%
Simple 0-shot Utility	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%
Simple (1-shot) 1-shot Utility	100%	100%	100%	100%	0%	0%	0%	0%	0%	0%	40%
Simple (5-shot) Few-shot Utility	100%	100%	100%	100%	100%	100%	100%	100%	0%	0%	80%
Unattributed dialogue 0-shot Utility	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
44.00%

Write N of X

Write exactly N words/sentences/paragraphs...

Scenario	Run 1	Run 2	Run 3	Run 4	Run 5	Run 6	Run 7	Run 8	Run 9	Run 10	Total
paragraphs
1 paragraph summary 0-shot Rule following	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
3 paragraph summary 0-shot Rule following	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
5 paragraph summary 0-shot Rule following	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
sentences
1 sentence summary 0-shot Rule following	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
3 sentence summary 0-shot Rule following	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
10 sentence summary 0-shot Rule following	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
20 sentence summary 0-shot Rule following	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
50 sentence summary 0-shot Rule following	100%	100%	100%	100%	100%	100%	100%	100%	100%	0%	90%
words
10 word summary 0-shot Rule following	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
20 word summary 0-shot Rule following	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%	100%
50 word summary 0-shot Rule following	100%	100%	100%	100%	100%	100%	100%	98%	98%	98%	100%
100 word summary 0-shot Rule following	100%	100%	100%	100%	100%	100%	100%	98%	92%	77%	97%
200 word summary 0-shot Rule following	100%	100%	98%	98%	98%	98%	92%	92%	77%	77%	93%
98.42%