Grok 4 Fast - NC Bench

x-ai/grok-4-fast

Grok 4 Fast

via OpenRouter

Release Date

Sep 19th, 2025

Context Size

Benchmark Cost

$0.49

Speed

151.9 tok/s

Creative writing

67.49%

Rule following

76.56%

Utility

81.64%

Mathematics

100.00%

Tooling

72.83%

Language

87.52%

Logic

91.72%

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 0-shot Creative writingRule following	79	76	75	74	72	75%
Horror: alone in an eerie place at night 0-shot Creative writingRule following	79	77	75	75	73	76%
Literary fiction: old friends reunite 0-shot Creative writingRule following	83	81	80	77	73	79%
Mystery: examining a crime scene 0-shot Creative writingRule following	75	75	72	69	68	72%
Romance: separated couple reunites 0-shot Creative writingRule following	81	80	78	78	76	79%
Thriller: chase through city streets 0-shot Creative writingRule following	80	79	78	78	77	78%
Detailed Writing Rules						76.44%
genre
Fantasy: entering an ancient ruin 0-shot Creative writingRule following	73	73	72	71	68	71%
Horror: alone in an eerie place at night 0-shot Creative writingRule following	81	80	78	72	68	76%
Literary fiction: old friends reunite 0-shot Creative writingRule following	80	79	79	78	76	78%
Mystery: examining a crime scene 0-shot Creative writingRule following	82	82	75	74	69	76%
Romance: separated couple reunites 0-shot Creative writingRule following	82	80	79	79	74	79%
Thriller: chase through city streets 0-shot Creative writingRule following	85	83	75	74	67	77%
genre						76.27%
Novelcrafter Default Prompt
Fantasy: entering an ancient ruin 0-shot Creative writingRule following	77	77	73	72	70	74%
Horror: alone in an eerie place at night 0-shot Creative writingRule following	80	80	78	73	71	77%
Literary fiction: old friends reunite 0-shot Creative writingRule following	85	83	82	82	80	82%
Mystery: examining a crime scene 0-shot Creative writingRule following	81	80	75	73	72	76%
Romance: separated couple reunites 0-shot Creative writingRule following	82	80	79	78	77	79%
Thriller: chase through city streets 0-shot Creative writingRule following	84	81	78	75	71	78%
Novelcrafter Default Prompt						77.59%
76.77%

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) 0-shot ToolingUtilityLogicRule following	100	100	99	97	96	95	94	92	91	90	96%
Large codex (40 entries), short passage (165 words) 0-shot ToolingUtilityLogicRule following	98	98	98	96	96	96	96	96	96	93	97%
Small codex (7 entries), long passage (734 words) 0-shot ToolingUtilityLogicRule following	100	100	95	95	93	92	92	92	87	83	93%
Small codex (7 entries), short passage (165 words) 0-shot ToolingUtilityLogicRule following	100	100	100	100	100	100	100	100	97	97	99%
matrix											96.13%
tiers
5 codex entries 0-shot ToolingUtilityLogicRule following	100	100	100	100	100	100	100	100	100	91	99%
10 codex entries 0-shot ToolingUtilityLogicRule following	100	100	100	100	100	100	100	100	100	69	97%
20 codex entries 0-shot ToolingUtilityLogicRule following	100	97	97	97	97	96	94	94	94	3	87%
40 codex entries 0-shot ToolingUtilityLogicRule following	100	100	100	100	100	100	100	100	100	100	100%
tiers											95.73%
95.93%

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 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	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
dialogue-200
Write 200 words with 10% dialogue 0-shot Creative writingRule following	50	49	49	47	47	41	41	38	22	18	40%
Write 200 words with 50% dialogue 0-shot Creative writingRule following	48	48	46	40	30	21	14	8	7	5	27%
Write 200 words with 90% dialogue 0-shot Creative writingRule following	81	56	50	43	31	18	14	8	2	2	30%
dialogue-200											32.37%
dialogue-500
Write 500 words with 30% dialogue 0-shot Creative writingRule following	50	49	48	26	22	10	0	0	0	0	21%
Write 500 words with 50% dialogue 0-shot Creative writingRule following	51	50	50	50	50	10	9	2	1	0	27%
Write 500 words with 70% dialogue 0-shot Creative writingRule following	97	92	89	74	67	50	47	43	37	11	61%
dialogue-500											36.15%
Ungrouped
Write unattributed dialogue 0-shot Creative writingRule following	100	100	100	100	100	100	100	100	100	100	100%
43.65%

Language Comprehension

Does the model understand more than just English?

Scenario	#1	#2	#3	#4	#5	Total
Asking for directions (Dutch) 0-shot Language	100	100	100	100	100	100%
Asking for directions (German) 0-shot Language	100	100	0	0	0	40%
Friend got new kittens (German) 0-shot Language	100	100	100	100	100	100%
Friend got new kittens (Tagalog) 0-shot Language	100	100	100	100	100	100%
85.00%

Language Writing

Can the model generate text in different languages?

Scenario	#1	#2	#3	#4	#5	Total
Character dialogue (French) in a story 0-shot Language	100	100	100	100	100	100%
Character dialogue (German) in a story 0-shot Language	100	100	100	100	86	97%
Character dialogue (Hindi) in a story 0-shot Language	57	56	50	45	44	51%
Character dialogue (Italian) in a story 0-shot Language	100	100	100	100	100	100%
Character dialogue (Spanish) in a story 0-shot Language	100	100	100	100	100	100%
89.53%

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 0-shot Rule following	89	78	78	78	78	78	70	70	67	53	74%
Write sentences with 10 words each 0-shot Rule following	93	92	90	90	90	90	72	68	48	35	77%
Write sentences with 20 words each 0-shot Rule following	36	23	16	8	8	1	0	0	0	0	9%
53.24%

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 0-shot ToolingUtility	100	100	100	100	100	100	100	100	0	0	80%
Count chapters 0-shot ToolingUtility	100	100	100	100	0	0	0	0	0	0	40%
Count scenes 0-shot ToolingUtility	100	100	100	100	100	100	100	0	0	0	70%
outline-count											63.33%
pov-count
Count point of views for Jack and Olivia 0-shot ToolingUtility	100	50	50	50	0	0	0	0	0	0	25%
Count point of views for Jack Harper 0-shot ToolingUtility	0	0	0	0	0	0	0	0	0	0	0%
Count point of views for Olivia 0-shot ToolingUtility	100	0	0	0	0	0	0	0	0	0	10%
pov-count											11.67%
37.50%

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 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	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
Multiple speakers 0-shot Utility	100	100	100	100	100	100	0	0	0	0	60%
Simple 0-shot Utility	100	100	100	100	100	100	100	100	0	0	80%
Simple (1-shot) 1-shot Utility	100	100	100	100	100	100	100	100	100	0	90%
Simple (5-shot) Few-shot Utility	100	100	100	100	100	100	100	100	100	0	90%
Unattributed dialogue 0-shot Utility	100	100	100	100	100	100	100	100	100	100	100%
84.00%

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 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%
paragraphs											100.00%
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	98	98	100%
50 sentence summary 0-shot Rule following	100	100	100	100	100	0	0	0	0	0	50%
sentences											89.92%
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	92	99%
50 word summary 0-shot Rule following	100	100	100	98	98	92	92	92	92	92	96%
100 word summary 0-shot Rule following	100	100	100	100	98	98	98	77	77	54	90%
200 word summary 0-shot Rule following	9	9	2	0	0	0	0	0	0	0	2%
words											77.44%
87.45%