Claude Sonnet 4.6

anthropic/claude-sonnet-4.6

Claude Sonnet 4.6

via OpenRouter

Release Date

Feb 17th, 2026

Context Size

Reasoning

Benchmark Cost

$12.10

Speed

57.0 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	89	89	87	86	84	87%
Horror: alone in an eerie place at night Creative Writing Hallucination	94	89	87	86	85	88%
Literary fiction: old friends reunite Creative Writing Hallucination	90	88	85	83	82	86%
Mystery: examining a crime scene Creative Writing Hallucination	93	91	87	87	86	89%
Romance: separated couple reunites Creative Writing Hallucination	86	86	84	84	80	84%
Thriller: chase through city streets Creative Writing Hallucination	95	94	89	87	84	90%
Detailed Writing Rules						87.29%
genre
Fantasy: entering an ancient ruin Creative Writing Hallucination	84	80	77	77	77	79%
Horror: alone in an eerie place at night Creative Writing Hallucination	85	82	81	80	77	81%
Literary fiction: old friends reunite Creative Writing Hallucination	82	80	77	77	73	78%
Mystery: examining a crime scene Creative Writing Hallucination	87	83	83	77	77	82%
Romance: separated couple reunites Creative Writing Hallucination	75	75	74	73	69	73%
Thriller: chase through city streets Creative Writing Hallucination	90	79	76	74	73	78%
genre						78.56%
Novelcrafter Default Prompt
Fantasy: entering an ancient ruin Creative Writing Hallucination	84	84	80	73	73	79%
Horror: alone in an eerie place at night Creative Writing Hallucination	87	86	82	81	75	82%
Literary fiction: old friends reunite Creative Writing Hallucination	82	81	79	78	78	80%
Mystery: examining a crime scene Creative Writing Hallucination	90	88	87	83	78	85%
Romance: separated couple reunites Creative Writing Hallucination	78	77	76	75	72	76%
Thriller: chase through city streets Creative Writing Hallucination	90	86	85	82	78	84%
Novelcrafter Default Prompt						80.94%
82.26%

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	97	97	96	96	97%
Medium: The Hollow (Inferred) Tooling Reasoning	98	98	98	98	98	98%
Medium: Through the Thornveil (Scattered) Tooling Reasoning	98	98	98	98	96	97%
Short: The Rusty Lantern (Explicit) Tooling Reasoning	99	99	99	98	98	99%
97.72%

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	100	100	50	42	42	29	17	10	59%
Long text (~1594 words), small codex (11 entries) Hallucination	100	100	100	100	100	100	100	100	100	32	93%
Short text (~524 words), big codex (51 entries) Hallucination	42	38	38	35	35	33	33	33	32	13	33%
Short text (~524 words), small codex (11 entries) Hallucination	42	38	38	38	38	35	35	35	35	8	34%
basic entries											54.80%
detailed entries
Long text (~1594 words), big codex (51 detailed entries) Hallucination	100	100	50	50	50	50	50	35	32	31	55%
Long text (~1594 words), small codex (11 detailed entries) Hallucination	100	100	100	100	100	100	100	100	33	25	86%
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											85.17%
69.98%

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	94	94	92	92	91	91	90	90	90	88	91%
Large codex (40 entries), short passage (165 words) Tooling Reasoning	100	100	100	100	98	98	98	98	96	94	98%
Small codex (7 entries), long passage (734 words) Tooling Reasoning	100	97	92	92	92	92	92	92	92	92	93%
Small codex (7 entries), short passage (165 words) Tooling Reasoning	92	92	92	92	92	92	92	92	92	92	92%
matrix											93.51%
tiers
5 codex entries Tooling Reasoning	83	83	83	83	83	83	83	83	83	83	83%
10 codex entries Tooling Reasoning	86	86	86	86	86	86	86	86	86	86	86%
20 codex entries Tooling Reasoning	100	100	97	97	94	94	92	89	86	86	93%
40 codex entries Tooling Reasoning	97	97	97	97	97	97	97	97	88	88	95%
tiers											89.46%
91.48%

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	50	50	50	50	50	50	50	50	50	50	50%
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	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	100	100%
83.33%

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	99	99	98	94	89	86	85	76	75	73	87%
Write 200 words with 50% dialogue Rule Following Utility	98	97	95	95	94	76	70	59	45	39	77%
Write 200 words with 90% dialogue Rule Following Utility	99	84	84	83	75	73	73	67	67	67	77%
dialogue-200											80.52%
dialogue-500
Write 500 words with 30% dialogue Rule Following Utility	74	55	55	53	53	50	48	47	45	34	51%
Write 500 words with 50% dialogue Rule Following Utility	78	78	52	49	48	47	40	39	30	25	49%
Write 500 words with 70% dialogue Rule Following Utility	66	57	57	49	42	33	26	21	19	3	37%
dialogue-500											45.70%
Ungrouped
Write unattributed dialogue Rule Following	100	100	100	100	100	100	100	100	61	61	92%
67.26%

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	100	100%
Friend got new kittens (German) Language	100	100	100	100	100	100%
Friend got new kittens (Tagalog) Language	100	100	100	100	100	100%
100.00%

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	100	100%
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%
100.00%

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	100	100	100	100	100%
Write sentences with 10 words each Utility	100	97	74	74	74	74	74	74	74	74	79%
Write sentences with 20 words each Utility	87	77	34	32	23	23	22	15	1	0	31%
70.12%

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	0	0	0	0	0	0	0	30%
outline-count											76.67%
pov-count
Count point of views for Jack and Olivia Utility	100	100	100	100	100	100	100	100	0	0	80%
Count point of views for Jack Harper Utility	100	100	100	0	0	0	0	0	0	0	30%
Count point of views for Olivia Utility	100	100	100	100	100	100	100	100	100	100	100%
pov-count											70.00%
73.33%

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	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	99	99	99	99	99	99	99	99%
Expand all contractions Text Editing	100	100	100	100	100	99	99	100%
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	95	94	94	93	93	93	93	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	97	97	97	97	97	97	97	97%
Generic Prompt								98.62%
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	99	99	99	99	99	99	98	99%
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	98	98	98	98	98	98	98	98%
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								99.67%
99.14%

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	100	100%
Simple Rule Following	100	100	100	100	100	100	100	100	100	100	100%
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%
100.00%

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	100	100	100	100	100%
50 sentence summary Utility	100	100	98	98	98	92	92	54	0	0	73%
sentences											94.66%
words
10 word summary Utility	100	100	100	100	100	100	98	98	92	92	98%
20 word summary Utility	100	100	100	100	100	100	100	100	100	98	100%
50 word summary Utility	100	100	100	98	98	92	92	77	77	9	84%
100 word summary Utility	100	100	98	98	98	92	92	92	92	54	92%
200 word summary Utility	2	0	0	0	0	0	0	0	0	0	0%
words											74.85%
88.27%