Grok 4.3 - NC Bench

x-ai/grok-4.3

Grok 4.3

via OpenRouter

Release Date

Apr 30th, 2026

Context Size

Reasoning

Benchmark Cost

$2.66

Speed

65.2 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	85	83	80	76	72	79%
Horror: alone in an eerie place at night Creative Writing Hallucination	91	85	84	81	81	84%
Literary fiction: old friends reunite Creative Writing Hallucination	87	85	84	84	82	84%
Mystery: examining a crime scene Creative Writing Hallucination	90	88	87	84	84	87%
Romance: separated couple reunites Creative Writing Hallucination	88	87	84	83	82	85%
Thriller: chase through city streets Creative Writing Hallucination	91	87	84	83	81	85%
Detailed Writing Rules						84.10%
genre
Fantasy: entering an ancient ruin Creative Writing Hallucination	78	74	73	73	72	74%
Horror: alone in an eerie place at night Creative Writing Hallucination	86	79	77	77	72	78%
Literary fiction: old friends reunite Creative Writing Hallucination	84	80	80	79	77	80%
Mystery: examining a crime scene Creative Writing Hallucination	88	87	85	83	79	84%
Romance: separated couple reunites Creative Writing Hallucination	86	83	80	80	77	81%
Thriller: chase through city streets Creative Writing Hallucination	88	85	83	79	74	82%
genre						79.95%
Novelcrafter Default Prompt
Fantasy: entering an ancient ruin Creative Writing Hallucination	85	83	82	79	78	81%
Horror: alone in an eerie place at night Creative Writing Hallucination	84	83	82	80	80	82%
Literary fiction: old friends reunite Creative Writing Hallucination	87	86	85	84	83	85%
Mystery: examining a crime scene Creative Writing Hallucination	87	84	84	82	81	84%
Romance: separated couple reunites Creative Writing Hallucination	87	87	86	85	76	84%
Thriller: chase through city streets Creative Writing Hallucination	87	83	81	81	80	82%
Novelcrafter Default Prompt						82.99%
82.35%

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	98	96	95	93	93	95%
Medium: The Hollow (Inferred) Tooling Reasoning	93	93	92	90	58	85%
Medium: Through the Thornveil (Scattered) Tooling Reasoning	97	96	96	96	96	96%
Short: The Rusty Lantern (Explicit) Tooling Reasoning	99	98	97	96	94	97%
93.23%

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	8	8	7	6	5	5	5	3	2	15%
Long text (~1594 words), small codex (11 entries) Hallucination	100	32	17	13	7	6	6	4	4	3	19%
Short text (~524 words), big codex (51 entries) Hallucination	100	100	28	17	17	13	13	10	7	4	31%
Short text (~524 words), small codex (11 entries) Hallucination	100	100	38	17	17	17	17	13	13	6	33%
basic entries											24.52%
detailed entries
Long text (~1594 words), big codex (51 detailed entries) Hallucination	100	100	26	17	10	8	6	5	2	1	28%
Long text (~1594 words), small codex (11 detailed entries) Hallucination	100	38	29	8	6	6	6	5	4	4	21%
Short text (~524 words), big codex (51 detailed entries) Hallucination	100	100	100	100	100	100	33	13	13	10	67%
Short text (~524 words), small codex (11 detailed entries) Hallucination	100	100	100	25	13	13	13	10	10	8	39%
detailed entries											38.50%
31.51%

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	85	82	80	77	76	71	71	56	3	3	60%
Large codex (40 entries), short passage (165 words) Tooling Reasoning	92	91	90	89	89	86	85	83	81	78	87%
Small codex (7 entries), long passage (734 words) Tooling Reasoning	93	90	90	84	84	83	80	75	73	71	82%
Small codex (7 entries), short passage (165 words) Tooling Reasoning	100	97	97	95	92	91	88	88	87	84	92%
matrix											80.32%
tiers
5 codex entries Tooling Reasoning	83	83	83	83	83	83	76	76	67	58	78%
10 codex entries Tooling Reasoning	100	94	92	86	86	79	79	72	69	3	76%
20 codex entries Tooling Reasoning	92	92	92	89	88	88	88	88	78	77	87%
40 codex entries Tooling Reasoning	88	83	83	79	75	75	72	71	68	3	70%
tiers											77.76%
79.04%

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	0	90%
Future event time Reasoning	100	100	100	100	100	100	100	50	50	50	85%
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	50	50	90%
Indirect birth year Reasoning	100	100	100	100	100	100	100	100	0	0	80%
What instrument does Lucy play? Reasoning	100	100	100	100	100	100	100	0	0	0	70%
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	0	0	0	0	0	0	0	0	0	0	0%
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	0	90%
83.75%

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	50	50	37	32	18	16	7	1	0	0	21%
Write 200 words with 50% dialogue Rule Following Utility	26	1	0	0	0	0	0	0	0	0	3%
Write 200 words with 90% dialogue Rule Following Utility	59	51	48	48	47	30	25	19	15	0	34%
dialogue-200											19.30%
dialogue-500
Write 500 words with 30% dialogue Rule Following Utility	50	3	3	0	0	0	0	0	0	0	6%
Write 500 words with 50% dialogue Rule Following Utility	48	1	0	0	0	0	0	0	0	0	5%
Write 500 words with 70% dialogue Rule Following Utility	43	32	18	3	3	0	0	0	0	0	10%
dialogue-500											6.79%
Ungrouped
Write unattributed dialogue Rule Following	100	100	100	100	100	100	61	14	14	1	69%
21.02%

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	0	80%
Asking for directions (German) Language	100	100	100	0	0	60%
Friend got new kittens (German) Language	100	100	100	100	0	80%
Friend got new kittens (Tagalog) Language	100	100	100	100	0	80%
75.00%

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	89	98%
Character dialogue (Hindi) in a story Language	100	100	63	57	53	75%
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%
94.47%

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	100	100	100	100	100	89	78	78	78	92%
Write sentences with 10 words each Utility	100	83	74	74	74	68	52	30	30	24	61%
Write sentences with 20 words each Utility	30	1	0	0	0	0	0	0	0	0	3%
52.13%

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	0	90%
Count chapters Utility	100	100	100	100	100	100	100	100	100	100	100%
Count scenes Utility	0	0	0	0	0	0	0	0	0	0	0%
outline-count											63.33%
pov-count
Count point of views for Jack and Olivia Utility	50	50	50	0	0	0	0	0	0	0	15%
Count point of views for Jack Harper Utility	100	0	0	0	0	0	0	0	0	0	10%
Count point of views for Olivia Utility	0	0	0	0	0	0	0	0	0	0	0%
pov-count											8.33%
35.83%

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	100	100	100	92	99%
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	97	96	93	84	70	91%
Expand all contractions Text Editing	100	100	100	100	100	100	67	95%
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	74	74	74	74	74	74	73	74%
Passive voice → active voice Text Editing Hallucination	97	96	92	90	83	74	62	85%
POV shift: 3rd person to 1st person (Elena's perspective) Text Editing	100	100	100	100	100	91	69	94%
Tense rewriting: past to present Text Editing	97	96	96	95	93	93	85	94%
Generic Prompt								92.39%
Specific Prompt
Avoid said/asked/replied/answered Text Editing	100	100	100	100	100	100	89	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	100	99	99	99	99	99	98	99%
Expand all contractions Text Editing	100	100	100	99	90	90	89	95%
Location rename: market square, outer ring, bridge, northern mines Text Editing	100	100	100	100	100	96	96	99%
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	98	96	95	95	93	92	92	94%
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	99	99	100%
Specific Prompt								98.45%
95.42%

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	0	90%
90.00%

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	0	0	0	0	0	0	0	30%
Simple Rule Following	100	100	100	100	100	100	100	0	0	0	70%
Simple (1-shot) 1-shot Rule Following	100	100	100	100	100	100	100	100	100	0	90%
Simple (5-shot) Few-shot Rule Following	100	100	100	100	100	100	100	100	100	100	100%
Unattributed dialogue Rule Following	100	0	0	0	0	0	0	0	0	0	10%
60.00%

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	0	0	0	0	60%
paragraphs											86.67%
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	100	100	100	98	100%
50 sentence summary Utility	100	100	98	92	54	27	0	0	0	0	47%
sentences											89.39%
words
10 word summary Utility	100	100	100	100	100	100	98	98	98	98	99%
20 word summary Utility	100	100	98	92	92	92	92	77	27	27	80%
50 word summary Utility	100	98	27	2	0	0	0	0	0	0	23%
100 word summary Utility	2	0	0	0	0	0	0	0	0	0	0%
200 word summary Utility	0	0	0	0	0	0	0	0	0	0	0%
words											40.43%
69.93%