ByteDance Seed 2.0 Lite

bytedance-seed/seed-2.0-lite

ByteDance Seed 2.0 Lite

via OpenRouter

Release Date

Mar 10th, 2026

Context Size

262k

Reasoning

Yes

Benchmark Cost

$4.55

Speed

41.1 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	87	83	82	77	73	80%
Horror: alone in an eerie place at night Creative Writing Hallucination	82	81	81	80	74	80%
Literary fiction: old friends reunite Creative Writing Hallucination	87	86	85	81	81	84%
Mystery: examining a crime scene Creative Writing Hallucination	89	84	83	81	81	84%
Romance: separated couple reunites Creative Writing Hallucination	84	80	77	75	74	78%
Thriller: chase through city streets Creative Writing Hallucination	83	80	79	78	77	79%
Detailed Writing Rules						80.86%
genre
Fantasy: entering an ancient ruin Creative Writing Hallucination	80	79	78	73	67	76%
Horror: alone in an eerie place at night Creative Writing Hallucination	80	80	78	78	73	78%
Literary fiction: old friends reunite Creative Writing Hallucination	83	77	74	73	72	76%
Mystery: examining a crime scene Creative Writing Hallucination	89	80	79	72	70	78%
Romance: separated couple reunites Creative Writing Hallucination	78	78	76	73	73	76%
Thriller: chase through city streets Creative Writing Hallucination	80	78	66	66	65	71%
genre						75.67%
Novelcrafter Default Prompt
Fantasy: entering an ancient ruin Creative Writing Hallucination	87	83	82	79	72	80%
Horror: alone in an eerie place at night Creative Writing Hallucination	86	85	80	80	78	82%
Literary fiction: old friends reunite Creative Writing Hallucination	87	83	82	81	81	83%
Mystery: examining a crime scene Creative Writing Hallucination	91	90	87	85	84	87%
Romance: separated couple reunites Creative Writing Hallucination	87	86	85	83	77	84%
Thriller: chase through city streets Creative Writing Hallucination	87	85	84	80	77	82%
Novelcrafter Default Prompt						83.15%
79.89%

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	96	96	96	94	93	95%
Medium: The Hollow (Inferred) Tooling Reasoning	97	97	96	96	95	96%
Medium: Through the Thornveil (Scattered) Tooling Reasoning	98	97	97	96	96	97%
Short: The Rusty Lantern (Explicit) Tooling Reasoning	98	97	96	95	93	96%
96.02%

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	25	17	17	17	17	17	17	17	13	13	17%
Long text (~1594 words), small codex (11 entries) Hallucination	25	25	25	25	25	25	25	17	17	17	23%
Short text (~524 words), big codex (51 entries) Hallucination	100	25	25	25	25	25	25	25	25	25	33%
Short text (~524 words), small codex (11 entries) Hallucination	25	25	25	25	25	25	25	25	25	25	25%
basic entries											24.17%
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	25	17	17	17	17	17	17	17	17	17	18%
Short text (~524 words), big codex (51 detailed entries) Hallucination	100	100	100	100	100	100	100	25	25	25	78%
Short text (~524 words), small codex (11 detailed entries) Hallucination	100	100	25	25	25	25	25	25	25	25	40%
detailed entries											58.75%
41.46%

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	95	95	93	92	92	91	91	88	87	86	91%
Large codex (40 entries), short passage (165 words) Tooling Reasoning	98	96	96	96	96	95	92	92	92	92	95%
Small codex (7 entries), long passage (734 words) Tooling Reasoning	97	97	97	93	93	92	88	88	88	84	92%
Small codex (7 entries), short passage (165 words) Tooling Reasoning	100	100	97	97	97	97	97	97	93	93	97%
matrix											93.49%
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	100	100	100	97	96	96	96	96	92	97%
40 codex entries Tooling Reasoning	97	97	97	97	97	97	97	97	97	97	97%
tiers											98.47%
95.98%

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	100	100	100	0	0	0	0	0	0	0	30%
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%
94.17%

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	95	91	60	53	51	50	46	18	66%
Write 200 words with 50% dialogue Rule Following Utility	100	70	50	50	47	27	0	0	0	0	34%
Write 200 words with 90% dialogue Rule Following Utility	64	59	50	50	45	9	3	2	0	0	28%
dialogue-200											42.92%
dialogue-500
Write 500 words with 30% dialogue Rule Following Utility	53	50	47	46	41	31	25	10	0	0	30%
Write 500 words with 50% dialogue Rule Following Utility	37	25	22	16	12	0	0	0	0	0	11%
Write 500 words with 70% dialogue Rule Following Utility	49	43	34	4	0	0	0	0	0	0	13%
dialogue-500											18.18%
Ungrouped
Write unattributed dialogue Rule Following	0	0	0	0	0	0	0	0	0	0	0%
26.18%

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	57	50	43	70%
Character dialogue (Italian) in a story Language	100	100	100	100	90	98%
Character dialogue (Spanish) in a story Language	100	100	100	100	100	100%
93.60%

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	98	92	99%
Write sentences with 10 words each Utility	100	100	100	100	100	100	100	100	98	97	100%
Write sentences with 20 words each Utility	100	100	100	100	100	100	100	100	100	93	99%
99.27%

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	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	0	0	0	70%
pov-count											88.33%
82.50%

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	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	95	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	94	94	94	93	91	91	90	93%
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	99	93	93	93	93	96%
Generic Prompt								98.53%
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	100	100	100	100	100	100	97	100%
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	96	96	95	95	94	94	62	90%
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								98.89%
98.71%

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	0	90%
Simple (1-shot) 1-shot Rule Following	100	100	100	100	100	100	0	0	0	0	60%
Simple (5-shot) Few-shot Rule Following	100	100	100	0	0	0	0	0	0	0	30%
Unattributed dialogue Rule Following	100	100	100	100	100	100	100	100	100	100	100%
76.00%

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	100	100	100	100	100	100	100	98	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	54	9	0	76%
words											95.25%
98.16%