DeepSeek V4 Flash

deepseek/deepseek-v4-flash

DeepSeek V4 Flash

via OpenRouter

Release Date

Apr 24th, 2026

Context Size

Reasoning

Benchmark Cost

$0.19

Speed

54.5 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	81	77	76	75	80%
Horror: alone in an eerie place at night Creative Writing Hallucination	90	87	84	82	80	85%
Literary fiction: old friends reunite Creative Writing Hallucination	93	85	83	81	81	85%
Mystery: examining a crime scene Creative Writing Hallucination	90	90	87	86	86	88%
Romance: separated couple reunites Creative Writing Hallucination	93	89	86	82	82	86%
Thriller: chase through city streets Creative Writing Hallucination	91	90	89	86	83	88%
Detailed Writing Rules						85.15%
genre
Fantasy: entering an ancient ruin Creative Writing Hallucination	78	76	76	76	75	76%
Horror: alone in an eerie place at night Creative Writing Hallucination	89	84	83	81	79	83%
Literary fiction: old friends reunite Creative Writing Hallucination	85	80	79	79	76	80%
Mystery: examining a crime scene Creative Writing Hallucination	90	83	82	80	78	83%
Romance: separated couple reunites Creative Writing Hallucination	88	85	83	80	76	83%
Thriller: chase through city streets Creative Writing Hallucination	84	83	83	81	75	81%
genre						80.87%
Novelcrafter Default Prompt
Fantasy: entering an ancient ruin Creative Writing Hallucination	80	79	74	73	72	75%
Horror: alone in an eerie place at night Creative Writing Hallucination	82	82	80	79	77	80%
Literary fiction: old friends reunite Creative Writing Hallucination	86	83	81	79	78	82%
Mystery: examining a crime scene Creative Writing Hallucination	83	82	82	81	80	81%
Romance: separated couple reunites Creative Writing Hallucination	89	87	84	84	83	85%
Thriller: chase through city streets Creative Writing Hallucination	86	83	80	77	74	80%
Novelcrafter Default Prompt						80.69%
82.24%

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	98	98	97	67	91%
Medium: The Hollow (Inferred) Tooling Reasoning	98	97	95	95	95	96%
Medium: Through the Thornveil (Scattered) Tooling Reasoning	96	96	96	95	94	95%
Short: The Rusty Lantern (Explicit) Tooling Reasoning	98	98	97	97	97	98%
95.14%

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	33	28	28	27	27	26	26	26	1	1	22%
Long text (~1594 words), small codex (11 entries) Hallucination	50	50	50	30	29	29	28	28	28	6	33%
Short text (~524 words), big codex (51 entries) Hallucination	50	30	30	30	28	28	28	28	10	8	27%
Short text (~524 words), small codex (11 entries) Hallucination	33	32	31	30	29	28	25	25	10	7	25%
basic entries											26.72%
detailed entries
Long text (~1594 words), big codex (51 detailed entries) Hallucination	50	38	29	29	27	26	26	17	10	10	26%
Long text (~1594 words), small codex (11 detailed entries) Hallucination	42	42	31	30	28	5	5	4	2	2	19%
Short text (~524 words), big codex (51 detailed entries) Hallucination	50	42	38	38	35	30	27	25	25	25	33%
Short text (~524 words), small codex (11 detailed entries) Hallucination	50	50	33	28	28	28	25	13	2	2	26%
detailed entries											26.07%
26.40%

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	87	85	81	81	79	77	76	75	73	66	78%
Large codex (40 entries), short passage (165 words) Tooling Reasoning	98	96	96	96	94	91	89	89	87	83	92%
Small codex (7 entries), long passage (734 words) Tooling Reasoning	97	97	92	88	88	88	87	83	83	83	89%
Small codex (7 entries), short passage (165 words) Tooling Reasoning	97	97	97	97	97	97	97	97	92	92	96%
matrix											88.53%
tiers
5 codex entries Tooling Reasoning	100	100	100	100	100	100	100	93	93	93	98%
10 codex entries Tooling Reasoning	100	92	92	92	86	86	86	86	79	79	88%
20 codex entries Tooling Reasoning	100	97	97	92	92	89	85	85	73	73	88%
40 codex entries Tooling Reasoning	87	87	83	83	83	79	79	79	75	52	79%
tiers											88.33%
88.43%

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	0	90%
Fruits excluding citrus Utility	100	100	100	100	100	100	100	100	100	100	100%
Future event time Reasoning	100	100	100	50	50	50	50	50	50	50	65%
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	0	0	0	0	0	0	0	0	0	0	0%
What instrument does Lucy play? Reasoning	0	0	0	0	0	0	0	0	0	0	0%
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%
71.25%

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	50	50	47	43	34	22	0	0	34%
Write 200 words with 50% dialogue Rule Following Utility	50	49	49	49	49	48	47	30	22	3	40%
Write 200 words with 90% dialogue Rule Following Utility	98	97	90	89	68	68	28	23	18	18	60%
dialogue-200											44.67%
dialogue-500
Write 500 words with 30% dialogue Rule Following Utility	50	50	49	43	1	0	0	0	0	0	19%
Write 500 words with 50% dialogue Rule Following Utility	50	43	22	18	14	0	0	0	0	0	15%
Write 500 words with 70% dialogue Rule Following Utility	49	41	27	18	10	5	0	0	0	0	15%
dialogue-500											16.26%
Ungrouped
Write unattributed dialogue Rule Following	100	100	100	100	100	100	100	100	100	100	100%
40.40%

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	100	100	100%
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	92	92	0	77%
Character dialogue (Hindi) in a story Language	100	100	100	50	50	80%
Character dialogue (Italian) in a story Language	100	100	100	100	91	98%
Character dialogue (Spanish) in a story Language	100	100	100	100	0	80%
87.00%

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	93	91	89	85	83	82	70	69	63	53	78%
Write sentences with 10 words each Utility	90	78	76	70	69	67	58	48	45	35	63%
Write sentences with 20 words each Utility	2	0	0	0	0	0	0	0	0	0	0%
47.15%

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	0	0	0	0	0	0	0	0	20%
outline-count											73.33%
pov-count
Count point of views for Jack and Olivia Utility	100	100	100	100	100	50	50	0	0	0	60%
Count point of views for Jack Harper Utility	100	100	100	100	100	100	100	0	0	0	70%
Count point of views for Olivia Utility	100	100	100	0	0	0	0	0	0	0	30%
pov-count											53.33%
63.33%

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	67	95%
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	98	91	98%
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	74	74	74	74	74	74	74	74%
Passive voice → active voice Text Editing Hallucination	96	95	95	95	95	90	59	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	100	99	99	99	97	96	96	98%
Generic Prompt								94.87%
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	99	99	99	99	99	99	93	98%
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								99.36%
97.11%

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	33	93%
93.33%

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	0	0	0	0	0	0	0	0	0	0	0%
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	0	0	0	70%
Unattributed dialogue Rule Following	100	100	100	100	0	0	0	0	0	0	40%
62.00%

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	98	100%
20 sentence summary Utility	100	100	100	100	100	100	100	100	100	100	100%
50 sentence summary Utility	100	100	100	100	100	100	100	98	92	77	97%
sentences											99.32%
words
10 word summary Utility	100	100	100	100	100	100	100	98	98	98	99%
20 word summary Utility	100	100	100	100	100	98	98	98	92	54	94%
50 word summary Utility	100	100	100	100	100	98	98	77	54	9	84%
100 word summary Utility	100	100	77	27	0	0	0	0	0	0	30%
200 word summary Utility	98	92	54	9	9	2	0	0	0	0	26%
words											66.81%
86.97%