ByteDance Seed 2.0 Mini

bytedance-seed/seed-2.0-mini

ByteDance Seed 2.0 Mini

via OpenRouter

Release Date

Feb 26th, 2026

Context Size

262k

Reasoning

Yes

Benchmark Cost

$1.99

Speed

38.7 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	82	80	78	77	73	78%
Horror: alone in an eerie place at night Creative Writing Hallucination	88	84	83	83	82	84%
Literary fiction: old friends reunite Creative Writing Hallucination	86	83	81	80	79	82%
Mystery: examining a crime scene Creative Writing Hallucination	86	82	80	78	77	81%
Romance: separated couple reunites Creative Writing Hallucination	81	81	80	80	80	80%
Thriller: chase through city streets Creative Writing Hallucination	83	77	76	75	74	77%
Detailed Writing Rules						80.22%
genre
Fantasy: entering an ancient ruin Creative Writing Hallucination	74	74	73	70	68	72%
Horror: alone in an eerie place at night Creative Writing Hallucination	80	80	78	66	64	74%
Literary fiction: old friends reunite Creative Writing Hallucination	84	81	78	74	70	77%
Mystery: examining a crime scene Creative Writing Hallucination	77	77	76	76	75	76%
Romance: separated couple reunites Creative Writing Hallucination	78	74	74	74	74	75%
Thriller: chase through city streets Creative Writing Hallucination	75	74	68	67	66	70%
genre						73.96%
Novelcrafter Default Prompt
Fantasy: entering an ancient ruin Creative Writing Hallucination	88	85	81	80	75	81%
Horror: alone in an eerie place at night Creative Writing Hallucination	84	81	81	79	76	80%
Literary fiction: old friends reunite Creative Writing Hallucination	85	81	80	76	73	79%
Mystery: examining a crime scene Creative Writing Hallucination	94	91	83	81	74	85%
Romance: separated couple reunites Creative Writing Hallucination	91	86	75	73	72	79%
Thriller: chase through city streets Creative Writing Hallucination	80	79	75	73	66	75%
Novelcrafter Default Prompt						79.82%
78.00%

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	94	94	94	93	91	93%
Medium: The Hollow (Inferred) Tooling Reasoning	97	96	95	95	94	95%
Medium: Through the Thornveil (Scattered) Tooling Reasoning	96	96	95	95	93	95%
Short: The Rusty Lantern (Explicit) Tooling Reasoning	97	97	95	93	89	94%
94.47%

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	35	17	17	17	17	17	17	17	17	17	19%
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	17	92%
Short text (~524 words), small codex (11 entries) Hallucination	100	100	100	100	100	100	100	100	100	25	93%
basic entries											75.67%
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	25	93%
Short text (~524 words), big codex (51 detailed entries) Hallucination	100	100	100	100	100	100	25	25	17	17	68%
Short text (~524 words), small codex (11 detailed entries) Hallucination	100	25	25	25	25	17	17	17	17	17	28%
detailed entries											72.29%
73.98%

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	93	92	91	90	90	90	90	88	88	91%
Large codex (40 entries), short passage (165 words) Tooling Reasoning	98	98	96	95	93	92	92	92	90	85	93%
Small codex (7 entries), long passage (734 words) Tooling Reasoning	100	97	97	97	97	97	93	93	88	84	94%
Small codex (7 entries), short passage (165 words) Tooling Reasoning	100	100	100	100	100	100	100	100	100	97	100%
matrix											94.40%
tiers
5 codex entries Tooling Reasoning	100	100	100	100	100	100	100	100	100	100	100%
10 codex entries Tooling Reasoning	100	100	100	100	100	100	100	100	100	100	100%
20 codex entries Tooling Reasoning	100	97	97	97	92	92	92	92	92	88	94%
40 codex entries Tooling Reasoning	100	100	100	100	100	100	97	97	97	92	98%
tiers											98.08%
96.24%

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	50	50	50	50	50	50	50	65%
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%
88.75%

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	98	94	76	76	72	68	67	57	50	50	71%
Write 200 words with 50% dialogue Rule Following Utility	100	97	87	59	53	52	50	50	41	0	59%
Write 200 words with 90% dialogue Rule Following Utility	87	63	50	49	38	2	0	0	0	0	29%
dialogue-200											52.82%
dialogue-500
Write 500 words with 30% dialogue Rule Following Utility	57	55	51	38	36	35	29	26	12	6	35%
Write 500 words with 50% dialogue Rule Following Utility	57	49	45	44	19	12	6	0	0	0	23%
Write 500 words with 70% dialogue Rule Following Utility	50	50	48	19	10	5	0	0	0	0	18%
dialogue-500											25.27%
Ungrouped
Write unattributed dialogue Rule Following	100	100	100	100	100	100	0	0	0	0	60%
42.04%

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	0	0	60%
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	86	40	85%
Character dialogue (German) in a story Language	100	100	100	100	91	98%
Character dialogue (Hindi) in a story Language	100	67	67	60	57	70%
Character dialogue (Italian) in a story Language	100	100	100	100	89	98%
Character dialogue (Spanish) in a story Language	100	100	100	100	100	100%
90.24%

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	98	98	97	99%
Write sentences with 10 words each Utility	100	100	100	100	100	100	100	97	97	97	99%
Write sentences with 20 words each Utility	100	100	100	100	100	100	100	100	100	100	100%
99.46%

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	0	0	0	0	0	0	40%
Count scenes Utility	100	100	100	100	100	100	0	0	0	0	60%
outline-count											66.67%
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	100	100%
Count point of views for Olivia Utility	100	100	100	100	100	100	100	100	0	0	80%
pov-count											91.67%
79.17%

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	72	96%
Character rename: Elena->Mirabel, Gregor->Aldric Text Editing	100	100	100	100	100	100	97	100%
Combined: 3rd person past → 1st person present Text Editing	98	93	90	89	85	83	68	86%
Expand all contractions Text Editing	100	100	100	100	99	99	99	100%
Location rename: market square, outer ring, bridge, northern mines Text Editing	100	100	100	100	96	96	96	98%
Multi-character gender swap: Priya(F)->Rohan(M), Mara unchanged Text Editing	74	74	74	74	74	73	72	73%
Passive voice → active voice Text Editing Hallucination	93	92	92	91	88	79	75	87%
POV shift: 3rd person to 1st person (Elena's perspective) Text Editing	100	100	100	100	100	100	92	99%
Tense rewriting: past to present Text Editing	98	97	97	93	93	93	89	94%
Generic Prompt								92.61%
Specific Prompt
Avoid said/asked/replied/answered Text Editing	100	100	100	100	100	72	72	92%
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	100	99	99	99	99	95	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	99	100%
Passive voice → active voice Text Editing Hallucination	98	96	96	95	94	94	93	95%
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								98.40%
95.51%

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	0	0	0	0	0	0	0	0	20%
Simple Rule Following	100	100	100	100	100	100	0	0	0	0	60%
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	0	0	0	0	0	0	40%
64.00%

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	100	100	100	100%
sentences											99.96%
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	100	100	100	100	100%
200 word summary Utility	100	100	100	100	100	100	100	100	27	0	83%
words											96.54%
98.65%