GPT-4.1 - NC Bench

openai/gpt-4.1

GPT-4.1

via OpenRouter

Release Date

Apr 14th, 2025

Context Size

Reasoning

Benchmark Cost

$5.27

Speed

118.7 tok/s

Subcategories

Bad Writing Habits

Detects common prose quality anti-patterns in AI-generated creative writing, including passive voice, past progressive overuse, weak dialogue tags, filter words, purple prose, cliches, AI-ism words/adverbs/names, and more.

Scenario	#1	#2	#3	#4	#5	Total
Detailed Writing Rules
Fantasy: entering an ancient ruin Creative Writing Hallucination	82	82	82	78	73	79%
Horror: alone in an eerie place at night Creative Writing Hallucination	85	82	80	78	75	80%
Literary fiction: old friends reunite Creative Writing Hallucination	86	85	84	83	79	83%
Mystery: examining a crime scene Creative Writing Hallucination	84	82	79	78	76	80%
Romance: separated couple reunites Creative Writing Hallucination	81	80	79	79	74	79%
Thriller: chase through city streets Creative Writing Hallucination	85	83	80	79	77	81%
Detailed Writing Rules						80.39%
genre
Fantasy: entering an ancient ruin Creative Writing Hallucination	86	77	77	77	76	79%
Horror: alone in an eerie place at night Creative Writing Hallucination	86	83	81	79	75	81%
Literary fiction: old friends reunite Creative Writing Hallucination	86	81	81	81	78	81%
Mystery: examining a crime scene Creative Writing Hallucination	84	83	79	76	75	79%
Romance: separated couple reunites Creative Writing Hallucination	84	83	80	78	77	80%
Thriller: chase through city streets Creative Writing Hallucination	87	86	85	81	76	83%
genre						80.68%
Novelcrafter Default Prompt
Fantasy: entering an ancient ruin Creative Writing Hallucination	81	81	78	74	74	78%
Horror: alone in an eerie place at night Creative Writing Hallucination	83	82	79	76	73	79%
Literary fiction: old friends reunite Creative Writing Hallucination	85	83	77	77	75	80%
Mystery: examining a crime scene Creative Writing Hallucination	85	82	82	79	73	80%
Romance: separated couple reunites Creative Writing Hallucination	83	82	81	78	76	80%
Thriller: chase through city streets Creative Writing Hallucination	85	85	83	83	79	83%
Novelcrafter Default Prompt						79.89%
80.32%

Codex Extraction

Evaluates a model's ability to extract structured codex entries (characters, locations, objects, lore) from prose passages and return them as well-formed XML.

Scenario	#1	#2	#3	#4	#5	Total
Long: The Spire of Echoes (Dense) Tooling Reasoning	92	91	91	91	90	91%
Medium: The Hollow (Inferred) Tooling Reasoning	95	95	94	93	90	93%
Medium: Through the Thornveil (Scattered) Tooling Reasoning	96	96	96	90	87	93%
Short: The Rusty Lantern (Explicit) Tooling Reasoning	91	91	90	84	81	87%
91.17%

Codex Red Herring (False Positive Detection)

Tests whether models correctly report "no violations" when a codex is fully consistent with the prose passage. Models that hallucinate false violations (false positives) fail. Uses a 2×2 matrix of text length × codex size, with bare and detailed-entry variants.

Scenario	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
basic entries
Long text (~1594 words), big codex (51 entries) Hallucination	100	100	50	42	35	33	33	30	17	8	45%
Long text (~1594 words), small codex (11 entries) Hallucination	100	100	100	100	100	100	100	100	100	100	100%
Short text (~524 words), big codex (51 entries) Hallucination	100	100	100	100	100	100	100	100	100	100	100%
Short text (~524 words), small codex (11 entries) Hallucination	100	100	42	42	38	25	17	17	17	17	41%
basic entries											71.52%
detailed entries
Long text (~1594 words), big codex (51 detailed entries) Hallucination	100	100	100	100	100	100	100	100	100	100	100%
Long text (~1594 words), small codex (11 detailed entries) Hallucination	100	100	100	100	100	100	100	100	100	100	100%
Short text (~524 words), big codex (51 detailed entries) Hallucination	100	100	100	100	100	100	100	100	100	100	100%
Short text (~524 words), small codex (11 detailed entries) Hallucination	100	100	100	100	100	100	100	100	100	100	100%
detailed entries											100.00%
85.76%

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	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
matrix
Large codex (40 entries), long passage (1,019 words) Tooling Reasoning	89	88	87	87	86	85	84	84	83	73	85%
Large codex (40 entries), short passage (165 words) Tooling Reasoning	100	100	98	96	96	95	91	90	88	86	94%
Small codex (7 entries), long passage (734 words) Tooling Reasoning	88	84	84	84	84	84	84	80	79	75	83%
Small codex (7 entries), short passage (165 words) Tooling Reasoning	100	100	100	100	100	100	100	100	100	95	100%
matrix											90.22%
tiers
5 codex entries Tooling Reasoning	100	100	100	100	100	100	100	100	100	100	100%
10 codex entries Tooling Reasoning	100	100	86	86	86	86	86	86	86	86	89%
20 codex entries Tooling Reasoning	96	94	94	94	94	94	89	85	3	3	75%
40 codex entries Tooling Reasoning	100	88	83	83	79	79	79	79	75	62	81%
tiers											86.10%
88.16%

Data extraction

Extract key details from a given block of text.

Scenario	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
All valid emails Utility	100	100	100	100	100	100	100	100	100	100	100%
Contextual pronoun Utility	100	100	100	100	100	100	100	100	100	100	100%
Fruits excluding citrus Utility	100	100	100	100	100	100	100	100	100	100	100%
Future event time Reasoning	50	50	50	50	50	50	50	50	50	50	50%
Guess the pet Reasoning	100	100	100	100	100	100	100	100	100	100	100%
Highest-rated movie Reasoning	100	100	100	100	100	100	100	100	100	100	100%
Indirect birth year Reasoning	100	100	100	100	100	100	100	100	100	100	100%
What instrument does Lucy play? Reasoning	100	100	100	100	100	100	100	100	100	100	100%
What's the color of the car? Utility	100	100	100	100	100	100	100	100	100	100	100%
What's the correct time? Reasoning	100	0	0	0	0	0	0	0	0	0	10%
Who's the sister? Reasoning	100	100	100	100	100	100	100	100	100	100	100%
Who's the tallest? Reasoning	100	100	100	100	100	100	100	100	100	100	100%
88.33%

Dialogue tags

Various tasks related to dialogue tags in text.

Scenario	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
dialogue-200
Write 200 words with 10% dialogue Rule Following Utility	51	50	50	50	50	50	50	49	48	44	49%
Write 200 words with 50% dialogue Rule Following Utility	50	50	50	50	50	50	50	49	49	5	45%
Write 200 words with 90% dialogue Rule Following Utility	68	68	68	68	68	59	50	49	44	43	59%
dialogue-200											50.97%
dialogue-500
Write 500 words with 30% dialogue Rule Following Utility	48	14	0	0	0	0	0	0	0	0	6%
Write 500 words with 50% dialogue Rule Following Utility	50	50	48	47	43	22	2	2	0	0	26%
Write 500 words with 70% dialogue Rule Following Utility	49	48	18	2	0	0	0	0	0	0	12%
dialogue-500											14.71%
Ungrouped
Write unattributed dialogue Rule Following	100	100	100	100	100	100	100	100	100	100	100%
42.44%

Language Comprehension

Does the model understand more than just English?

Scenario	#1	#2	#3	#4	#5	Total
Asking for directions (Dutch) Language	100	100	100	100	100	100%
Asking for directions (German) Language	100	100	100	100	0	80%
Friend got new kittens (German) Language	100	100	100	100	0	80%
Friend got new kittens (Tagalog) Language	100	100	100	100	100	100%
90.00%

Language Writing

Can the model generate text in different languages?

Scenario	#1	#2	#3	#4	#5	Total
Character dialogue (French) in a story Language	100	100	100	100	100	100%
Character dialogue (German) in a story Language	100	100	100	100	100	100%
Character dialogue (Hindi) in a story Language	100	100	100	100	45	89%
Character dialogue (Italian) in a story Language	100	100	100	100	100	100%
Character dialogue (Spanish) in a story Language	100	100	100	100	100	100%
97.82%

N-Length Sentences

Write sentences with exactly N words

Scenario	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
Write sentences with 5 words each Utility	100	98	98	98	97	96	96	89	88	78	94%
Write sentences with 10 words each Utility	100	97	97	95	92	92	92	90	83	79	92%
Write sentences with 20 words each Utility	93	92	85	84	84	80	72	72	67	57	79%
88.08%

Novel outline

Handle questions about the outline of a novel in various formats

Scenario	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
outline-count
Count acts Utility	100	100	100	100	100	100	100	100	100	100	100%
Count chapters Utility	100	100	100	100	100	100	100	100	100	100	100%
Count scenes Utility	100	100	100	100	100	100	0	0	0	0	60%
outline-count											86.67%
pov-count
Count point of views for Jack and Olivia Utility	100	100	100	100	100	100	100	100	50	0	85%
Count point of views for Jack Harper Utility	100	100	100	100	100	100	100	100	100	100	100%
Count point of views for Olivia Utility	100	100	100	100	100	100	100	0	0	0	70%
pov-count											85.00%
85.83%

Text Replacement

Tests deterministic text transformations: renaming characters/locations, expanding contractions, tense rewriting, POV shifts, gender swaps, combined transformations, and word avoidance. Scored by checking each expected change independently.

Scenario	#1	#2	#3	#4	#5	#6	#7	Total
Generic Prompt
Avoid said/asked/replied/answered Text Editing	100	100	100	97	97	97	94	98%
Character rename: Elena->Mirabel, Gregor->Aldric Text Editing	100	100	100	100	100	100	100	100%
Combined: 3rd person past → 1st person present Text Editing	99	99	99	99	98	98	98	99%
Expand all contractions Text Editing	100	100	100	100	100	100	99	100%
Location rename: market square, outer ring, bridge, northern mines Text Editing	100	100	100	100	100	100	100	100%
Multi-character gender swap: Priya(F)->Rohan(M), Mara unchanged Text Editing	100	100	100	100	100	100	100	100%
Passive voice → active voice Text Editing Hallucination	94	94	94	93	90	81	77	89%
POV shift: 3rd person to 1st person (Elena's perspective) Text Editing	100	100	100	100	100	100	100	100%
Tense rewriting: past to present Text Editing	97	93	89	89	89	89	88	90%
Generic Prompt								97.32%
Specific Prompt
Avoid said/asked/replied/answered Text Editing	100	100	100	100	100	100	100	100%
Character rename: Elena->Mirabel, Gregor->Aldric Text Editing	100	100	100	100	100	100	100	100%
Combined: 3rd person past → 1st person present Text Editing	100	100	100	100	100	100	100	100%
Expand all contractions Text Editing	100	100	100	100	100	100	100	100%
Location rename: market square, outer ring, bridge, northern mines Text Editing	100	100	100	100	100	100	100	100%
Multi-character gender swap: Priya(F)->Rohan(M), Mara unchanged Text Editing	100	100	100	100	100	100	100	100%
Passive voice → active voice Text Editing Hallucination	94	93	92	92	92	92	91	92%
POV shift: 3rd person to 1st person (Elena's perspective) Text Editing	100	100	100	100	100	100	100	100%
Tense rewriting: past to present Text Editing	100	100	100	100	100	100	100	100%
Specific Prompt								99.14%
98.23%

Tool usage within Novelcrafter

Output messages that are related to tool usage within Novelcrafter

Scenario	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
Create alternate prose sections Tooling	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	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
Multiple speakers Rule Following	100	100	100	100	100	100	100	100	100	0	90%
Simple Rule Following	100	100	100	100	100	100	100	100	100	0	90%
Simple (1-shot) 1-shot Rule Following	100	100	100	100	100	100	100	100	100	100	100%
Simple (5-shot) Few-shot Rule Following	100	100	100	100	100	100	100	100	100	100	100%
Unattributed dialogue Rule Following	100	100	100	100	100	100	100	100	100	100	100%
96.00%

Write N of X

Write exactly N words/sentences/paragraphs...

Scenario	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
paragraphs
1 paragraph summary Utility	100	100	100	100	100	100	100	100	100	100	100%
3 paragraph summary Utility	100	100	100	100	100	100	100	100	100	100	100%
5 paragraph summary Utility	100	100	100	100	100	100	100	100	100	100	100%
paragraphs											100.00%
sentences
1 sentence summary Utility	100	100	100	100	100	100	100	100	100	100	100%
3 sentence summary Utility	100	100	100	100	100	100	100	100	100	100	100%
10 sentence summary Utility	100	100	100	100	100	100	100	100	100	100	100%
20 sentence summary Utility	100	100	100	100	100	100	98	98	98	9	90%
50 sentence summary Utility	100	100	98	98	0	0	0	0	0	0	40%
sentences											86.01%
words
10 word summary Utility	100	100	100	100	100	100	100	100	100	100	100%
20 word summary Utility	100	100	100	100	100	100	100	98	98	98	99%
50 word summary Utility	100	100	100	100	100	100	98	98	92	77	97%
100 word summary Utility	100	100	100	100	100	100	100	98	98	92	99%
200 word summary Utility	100	100	98	98	98	92	77	77	27	9	78%
words											94.56%
92.53%