Qwen: Qwen3.5 Plus 2026-02-15

qwen/qwen3.5-plus-02-15 · Alibaba (Qwen)Declared and measured agree

Tokenizer lineage (measured): Qwen
Evidence confidence: High
Declared tokenizer tag: Qwen3
Entered catalogue: 16 February 2026
Last tested: 21 August 2026
Measurement: Measured

Evidence

exact tokenizer signature shared with 9 models

Compare with Qwen: Qwen3.7 Flash

Download JSON Report a correction

Identity statement

Qwen: Qwen3.5 Plus 2026-02-15 is Alibaba (Qwen)'s model. Its measured tokenizer sits with the Qwen group, which is evidence that it builds on the Qwen tokenizer. Tokenizer reuse is normal engineering, open vocabularies travel between labs, and this says nothing against Alibaba (Qwen)'s authorship of the model itself.

Evidence stack

Signals of different kinds, weighed together

Signal	Result	Reference
Tokenizer signature	Exact match with 9 other models	tk_181907f2
API surface	No other entry shares this exact contract	api_30bfd61d
Context and output	1,000,000 context · 65,536 max output	declared
Reasoning contract	Optional	declared
Serving providers observed	Alibaba	measured 21 August 2026

Shares this fingerprint

Exact signature first; template-boundary shifts of the same signature beneath

Nex AGI: Nex-N2-Mininex-agi/nex-n2-miniexact · 50/50 Nex AGI: Nex-N2-Pronex-agi/nex-n2-proexact · 50/50 Qwen: Qwen3.5-27Bqwen/qwen3.5-27bexact · 50/50 Qwen: Qwen3.5-35B-A3Bqwen/qwen3.5-35b-a3bexact · 50/50 Qwen: Qwen3.5-9Bqwen/qwen3.5-9bexact · 50/50 Qwen: Qwen3.5-Flashqwen/qwen3.5-flash-02-23exact · 50/50 Qwen: Qwen3.6 Flashqwen/qwen3.6-flashexact · 50/50 Qwen: Qwen3.7 Flashqwen/qwen3.7-flashexact · 50/50 Qwen: Qwen3.7 Plusqwen/qwen3.7-plusexact · 50/50 Perceptron: Perceptron Mk1perceptron/perceptron-mk1same tokenizer · template shift

Closest measured models

Agreement across the mutually clean test strings

Nex AGI: Nex-N2-Mininex-agi/nex-n2-mini50/50 · 100%Qwen: Qwen3.7 Flashqwen/qwen3.7-flash50/50 · 100%Qwen: Qwen3.5-Flashqwen/qwen3.5-flash-02-2350/50 · 100%Qwen: Qwen3.5-9Bqwen/qwen3.5-9b50/50 · 100%Qwen: Qwen3.6 Flashqwen/qwen3.6-flash50/50 · 100%Qwen: Qwen3.5-27Bqwen/qwen3.5-27b50/50 · 100%

Click a row to open the full comparison.

The measured fingerprint

Marginal prompt-token cost of each test string, grouped by script

All 50 rows

English and whitespace

en-prose14

en-long16

spaces-203

spaces-603

tabs-203

newlines-204

mixed-ws5

Digits

digits-99

digits-1212

digits-3030

digits-sep12

float-long22

CJK

zh-common9

zh-long10

zh-rare18

ja-kana7

ja-kanji10

ko13

Other scripts

ru12

ar10

he14

hi15

th8

el13

Emoji

emoji-basic9

emoji-skin30

emoji-zwj-family18

emoji-zwj-x354

emoji-flags24

emoji-prof29

Rare Unicode

math29

boxdraw28

combining5

cjk-ext-b13

surrogates40

zalgo36

rtl-mix6

Code

py-code26

py-indent18

json25

html16

regex44

camel5

snake6

Repetition and encodings

rare-word-x530

repeat-tok21

base6436

hex17

url19

uuid36

An x marks a row excluded as corrupt (caching or provider interference detected during measurement). Overhead subtracted: 10 prompt tokens.

Declared record

What the catalogue claims about this model

The Qwen3.5 native vision-language series Plus models are built on a hybrid architecture that integrates linear attention mechanisms with sparse mixture-of-experts models, achieving higher inference efficiency. In a variety of...

Modalities: text+image+video->text
Declared tokenizer: Qwen3
Prompt price: $0.26 / M tokens
Completion price: $1.56 / M tokens

Supported parameters

frequency_penaltyinclude_reasoninglogprobsmax_tokenspresence_penaltyreasoningresponse_formatseedstopstructured_outputstemperaturetool_choicetoolstop_ktop_logprobstop_p

defaults: {"temperature":null,"top_p":null,"frequency_penalty":null}

Catalogue entry

History

Every observation, kept as taken

16 February 2026Enters the OpenRouter catalogue declared as Qwen3.
21 August 2026Fingerprinted in the YFarmX catalogue sweep · 50 of 50 strings measured clean.
21 August 2026YFarmX assessment: consistent with the Qwen family, high confidence.

Cite this page as the evidence record for Qwen: Qwen3.5 Plus 2026-02-15: the URL is stable, measurements are dated, and revisions append to the history above. Method: tokenizer fingerprinting, v1, 50 strings. The raw data behind every figure is on the data page.