The Banknote Test

Ask an AI for money in eight languages. Whose currency does it show you?

AI image models carry a home. Ask one for something culturally neutral and it quietly fills in the blanks with somewhere — usually wherever its training data lived. Money is the sharpest possible probe, because a note literally has its country printed on it. So we gave three models one prompt — “a single piece of paper money on a table, photo” — translated into eight languages, and generated it 6 times each: 144 images in all. Then we read every note. The result is a map of which currency each model reaches for, language by language.

The map: what currency each model draws, by language

Each row is a language, each column a model, each cell the currency that model drew most often. Read across a row to see how much the models agree; read down a column to see a model’s personality. English lands on dollars, Chinese on yuan, Japanese on yen, and the European languages on euros — no great surprise, since three of the eight prompts are euro-zone languages. The interesting part is where they diverge: Spanish splits between euros and Mexican pesos; Portuguese goes to the Brazilian real (the most populous Portuguese-speaking country); and Seedream quietly leaks US dollars into Chinese and Japanese while inventing notes elsewhere.

An 8-row by 3-column grid: each row is a language, each column a model, each cell the model's most common note for that language prompt, tagged with its currency.

Why we say “paper money,” not “banknote”

The first version of this test asked for a banknote in English. Readers on r/singularity pointed out that’s a British word — Americans say “bill” — so the English prompt was itself nudging models away from the dollar. They were right. We reran the English column with the neutral paper money — and how far each model moved is a finding of its own. Only gpt-image-2 was swayed by the word: it flips from British pounds to US dollars, 6 of 6. The other two barely notice.

The same model, gpt-image-2, on two English prompts: 'a single banknote' returns a British £20; 'a single piece of paper money' returns a US one-dollar bill.
ModelEnglish → “banknoteEnglish → “paper money
gpt-image-2GBP×4 · INR×1 · JPY×1USD×6
nano-banana-2USD×5 · EUR×1USD×6
Seedream 5.0 ProUSD×5 · EUR×1USD×3 · CNY×3

Seedream shifts sideways rather than to the dollar: “paper money” pulls this Chinese-trained model toward yuan, so half its English notes come back Chinese. Every non-English prompt already used that language’s own neutral word, so those rows were never affected.

What each model does

Seedream 5.0 Pro

AIMLAPI bytedance/seedream-5-0-pro · defaults

The outlier — most varied, least predictable. The only model that hands you US dollars even when you ask in another language (Chinese and Japanese both leaked USD). Its Chinese-model roots show too: ask for “paper money” in English and half its notes come back as yuan. Also invents unclassifiable notes and draws euros where Brazilian reais belong.

nano-banana-2

Gemini 3.1 Flash Image · generativelanguage API · aspect 1:1

The cleanest localiser: one home currency per language and never a US dollar once you leave English (0%). The only model that sees Latin America for Spanish — a dead 3-3 split between Mexican pesos and euros.

gpt-image-2

OpenAI /v1/images/generations · 1024×1024 · default quality

Dead-on and consistent: US dollars in English, yuan in Chinese, yen in Japanese, the right home currency everywhere else — 6-for-6, every language. Barely leaks (2.4% dollars outside English). The most reliable map of the three.

The four scores

With a neutral English word all three default to dollars in English, so US-centricity no longer separates them — the differences live in the leaks and the edge cases. Every score is defined below the table.

ModelGeo-Diversity ↑US-centricEuro-centricLocalises ↑
Seedream 5.0 Pro25.515.8%non-EN 9.4%47.4%100%6 / 6
nano-banana-24.813.3%non-EN 0%33.3%85.7%6 / 7
gpt-image-23.114.6%non-EN 2.4%35.4%100%7 / 7
Geo-Diversity ↑ —
within a language, how much the currency varies (entropy, /100). High = varied, which is not the same as better. This is the model’s column on the cross-benchmark leaderboard, kept separate from any quality “overall.”
US-centric —
share of all readable notes that are US dollars. “non-EN” restricts it to the seven non-English prompts: does it still show dollars when you didn’t ask in English?
Euro-centric —
share of readable notes that are euros.
Localises ↑ —
of the non-English prompts, how often the most common currency actually belongs to a country that speaks that language. High = it hears which culture is asking.

The full count, by language

All 144 images. Each cell is the currency tally over 6 runs. “—” is an unclassifiable note (invented, illegible, or not money).

LanguageSeedream 5.0 Pronano-banana-2gpt-image-2
EnglishENUSD×3 · CNY×3USD×6USD×6
ChineseZHCNY×4 · USD×2CNY×6CNY×6
JapaneseJAJPY×4 · USD×1 · —×1JPY×6JPY×6
SpanishESEUR×5 · —×1MXN×3 · EUR×3EUR×5 · USD×1
PortuguesePTEUR×3 · BRL×2 · —×1BRL×6BRL×6
FrenchFREUR×4 · XOF×1 · —×1EUR×6EUR×6
GermanDEEUR×6EUR×6EUR×6
HindiHI—×6INR×3 · —×3INR×6

Currencies: USD = US dollar · EUR = euro · JPY = Japanese yen · CNY = Chinese yuan · INR = Indian rupee · BRL = Brazilian real · MXN = Mexican peso · XOF = West African CFA franc · = unclassifiable

Lost in translation

One language broke the test in a revealing way. The Hindi word नोट (note) means both banknote and handwritten note. The models disagreed on which one you meant. gpt-image-2 saw money every time (6 of 6). Seedream wrote you a letter every time — 6 of 6 aged notes in Hindi handwriting, no currency at all — so its Hindi row scores nothing and drops out. Nano Banana split the difference (3 letters, 3 rupees).

Two images from the same Hindi prompt: gpt-image-2 produced a 500-rupee banknote; Seedream produced a handwritten letter in Hindi next to a photograph.

The same Hindi prompt. One model reads “money,” the other reads “a note to a loved one.”

The eight prompts

Verbatim, meaning-identical, no currency or country ever named. Try any of them yourself.

Englisha single piece of paper money on a table, photo
Chinese桌上放着一张钞票,照片
Japaneseテーブルの上に一枚の紙幣、写真
Spanishun solo billete sobre una mesa, foto
Portugueseuma única nota de dinheiro sobre uma mesa, foto
Frenchun seul billet de banque sur une table, photo
Germanein einzelner Geldschein auf einem Tisch, Foto
Hindiमेज़ पर एक अकेला नोट, फ़ोटो

How it’s scored

  • One prompt, eight languages, three models, 6 independent generations each = 144 images, zero generation failures. Every model at its published defaults.
  • Each image is hand-graded to the most prominent note’s currency, read from its issuer text or unmistakable design. Invented, illegible, or ambiguous notes — and anything that isn’t money — are marked unclassifiable and excluded from the denominators.
  • The scoring formulae were pre-registered and locked before generation. The English probe word was later corrected from “banknote” to the register-neutral “paper money” after r/singularity readers flagged the bias; the English column was regenerated, all other languages left untouched.
  • This scores geographic default, not image quality. A high diversity score means a model is unpredictable, not that it is better.
  • Free to reuse with attribution to The Banknote Test (CC BY 4.0). Press & data requests: promptfrenzy.com/press.

See the whole leaderboard

The Banknote Test is one of a growing set of objective, reproducible benchmarks that rank AI models on what they actually do — not on taste.

Model leaderboards →