GPT-5.4 Nano (Reasoning, Low)

openai/gpt-5.4-nano

GPT-5.4 Nano (Reasoning, Low)

via OpenRouter

Release Date

Mar 17th, 2026

Context Size

400k

Reasoning

Yes

Benchmark Cost

$1.14

Speed

130.4 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	81	81	77	76	72	77%
Horror: alone in an eerie place at night Creative Writing Hallucination	89	88	87	81	78	85%
Literary fiction: old friends reunite Creative Writing Hallucination	87	86	84	82	81	84%
Mystery: examining a crime scene Creative Writing Hallucination	87	84	83	83	73	82%
Romance: separated couple reunites Creative Writing Hallucination	87	86	82	81	78	83%
Thriller: chase through city streets Creative Writing Hallucination	85	84	80	80	79	81%
Detailed Writing Rules						82.07%
genre
Fantasy: entering an ancient ruin Creative Writing Hallucination	77	75	74	73	72	74%
Horror: alone in an eerie place at night Creative Writing Hallucination	85	83	77	76	73	79%
Literary fiction: old friends reunite Creative Writing Hallucination	80	79	79	76	76	78%
Mystery: examining a crime scene Creative Writing Hallucination	84	81	81	79	77	81%
Romance: separated couple reunites Creative Writing Hallucination	81	79	79	78	74	78%
Thriller: chase through city streets Creative Writing Hallucination	82	82	81	77	77	80%
genre						78.35%
Novelcrafter Default Prompt
Fantasy: entering an ancient ruin Creative Writing Hallucination	80	77	77	77	74	77%
Horror: alone in an eerie place at night Creative Writing Hallucination	85	84	83	80	78	82%
Literary fiction: old friends reunite Creative Writing Hallucination	86	84	82	81	81	83%
Mystery: examining a crime scene Creative Writing Hallucination	87	85	83	81	81	84%
Romance: separated couple reunites Creative Writing Hallucination	83	82	81	80	80	81%
Thriller: chase through city streets Creative Writing Hallucination	83	81	81	81	80	81%
Novelcrafter Default Prompt						81.33%
80.58%

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	91	88	88	87	83	87%
Medium: The Hollow (Inferred) Tooling Reasoning	90	87	85	83	82	86%
Medium: Through the Thornveil (Scattered) Tooling Reasoning	83	81	77	77	66	77%
Short: The Rusty Lantern (Explicit) Tooling Reasoning	92	86	84	84	81	85%
83.77%

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	100	100	100	100	100	100	100%
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	4	90%
Short text (~524 words), small codex (11 entries) Hallucination	100	100	100	100	100	100	100	100	100	100	100%
basic entries											97.60%
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	29	93%
Short text (~524 words), small codex (11 detailed entries) Hallucination	100	100	100	100	100	100	100	100	100	33	93%
detailed entries											96.55%
97.08%

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	82	77	75	75	73	64	0	0	0	0	45%
Large codex (40 entries), short passage (165 words) Tooling Reasoning	95	93	93	88	0	0	0	0	0	0	37%
Small codex (7 entries), long passage (734 words) Tooling Reasoning	88	88	84	79	0	0	0	0	0	0	34%
Small codex (7 entries), short passage (165 words) Tooling Reasoning	100	97	93	93	88	0	0	0	0	0	47%
matrix											40.63%
tiers
5 codex entries Tooling Reasoning	100	100	100	93	60	54	0	0	0	0	51%
10 codex entries Tooling Reasoning	86	60	56	52	28	3	3	0	0	0	29%
20 codex entries Tooling Reasoning	91	91	89	88	79	0	0	0	0	0	44%
40 codex entries Tooling Reasoning	93	92	92	88	88	61	41	0	0	0	55%
tiers											44.67%
42.65%

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	100	100	100	100	100	100	100	100	100	100	100%
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	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%
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 Rule Following Utility	100	100	100	100	99	91	72	50	50	46	81%
Write 200 words with 50% dialogue Rule Following Utility	100	100	100	100	99	95	59	53	50	45	80%
Write 200 words with 90% dialogue Rule Following Utility	100	52	50	50	50	50	49	36	27	18	48%
dialogue-200											69.70%
dialogue-500
Write 500 words with 30% dialogue Rule Following Utility	37	17	12	4	3	3	1	0	0	0	8%
Write 500 words with 50% dialogue Rule Following Utility	49	41	32	26	21	6	5	0	0	0	18%
Write 500 words with 70% dialogue Rule Following Utility	50	10	2	0	0	0	0	0	0	0	6%
dialogue-500											10.64%
Ungrouped
Write unattributed dialogue Rule Following	61	14	14	1	1	1	0	0	0	0	9%
35.73%

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	0	0	0	40%
Friend got new kittens (German) Language	100	100	100	0	0	60%
Friend got new kittens (Tagalog) Language	100	100	100	100	100	100%
70.00%

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	98	100%
Character dialogue (German) in a story Language	100	100	100	98	95	98%
Character dialogue (Hindi) in a story Language	100	99	55	53	49	71%
Character dialogue (Italian) in a story Language	100	100	100	100	100	100%
Character dialogue (Spanish) in a story Language	100	100	100	99	98	99%
93.74%

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	100	100	100	100	100	100	100	100	100	100%
Write sentences with 20 words each Utility	100	100	100	100	100	100	100	100	100	86	99%
99.52%

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	100	100	100	0	90%
outline-count											96.67%
pov-count
Count point of views for Jack and Olivia Utility	100	100	100	100	100	100	100	100	100	50	95%
Count point of views for Jack Harper Utility	100	100	100	100	100	100	100	100	100	0	90%
Count point of views for Olivia Utility	100	100	100	100	100	0	0	0	0	0	50%
pov-count											78.33%
87.50%

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	78	78	67	67	67	79%
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	95	95	95	95	97%
Expand all contractions Text Editing	99	98	98	98	98	98	97	98%
Location rename: market square, outer ring, bridge, northern mines Text Editing	100	100	100	96	96	96	96	98%
Multi-character gender swap: Priya(F)->Rohan(M), Mara unchanged Text Editing	100	99	99	99	99	86	74	94%
Passive voice → active voice Text Editing Hallucination	83	81	74	73	71	71	69	75%
POV shift: 3rd person to 1st person (Elena's perspective) Text Editing	100	100	100	100	100	100	99	100%
Tense rewriting: past to present Text Editing	96	95	95	91	91	89	89	92%
Generic Prompt								92.51%
Specific Prompt
Avoid said/asked/replied/answered Text Editing	100	89	89	78	67	67	67	79%
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	98	98	96	96	95	94	86	95%
Expand all contractions Text Editing	95	94	92	91	91	91	91	92%
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	99	99	99	95	95	98%
Passive voice → active voice Text Editing Hallucination	94	93	91	78	78	77	77	84%
POV shift: 3rd person to 1st person (Elena's perspective) Text Editing	100	100	100	99	99	99	99	99%
Tense rewriting: past to present Text Editing	100	97	97	95	95	92	92	95%
Specific Prompt								93.74%
93.12%

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	0	0	0	0	0	0	0	0	0	0	0%
Simple Rule Following	0	0	0	0	0	0	0	0	0	0	0%
Simple (1-shot) 1-shot Rule Following	100	100	100	100	100	100	100	0	0	0	70%
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	0	0	0	0	0	0	0	30%
40.00%

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	98	98	100%
20 sentence summary Utility	100	100	100	98	92	92	92	92	77	77	92%
50 sentence summary Utility	100	100	100	98	98	77	77	54	27	9	74%
sentences											93.19%
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	100	100	100	100%
50 word summary Utility	100	100	100	100	100	100	100	100	100	100	100%
100 word summary Utility	100	100	100	100	100	100	98	98	98	0	90%
200 word summary Utility	100	92	92	77	54	2	0	0	0	0	42%
words											86.23%
92.09%