Gemini 2.5 Flash Lite Behavioral Fingerprint
How Google's Gemini 2.5 Flash Lite answers one-word probe questions at temperature 1.0 — random numbers, colors, animals, coin flips — measured over 435 valid samples in the open dataset of "One Token Is Enough" (arXiv:2607.10252).
Vendor
Data generated
2026-07-08
Probe cells
15
Valid samples
435
Randomness score
36 / 100
Mean normalized entropy across cells, 0–100. 100 would be a uniform-random baseline; real models score far lower.
Signature answers
Favorite random number (1–100)
42
17 / 30 answers
Favorite color
teal
14 / 30 answers
Coin flip: heads
93%
Share of heads across coin-flip cells.
Answer distributions by probe cell
Empirical distributions of normalized one-word answers, per task and language. H is the Shannon entropy in bits; the uniform baseline is log2 of the answer-domain size.
Coin flip · English
n = 30 · H = 0.35 bit · uniform baseline 1.00 bit
| Answer | Count | Share |
|---|---|---|
| heads | 28 | 93.3% |
| tails | 2 | 6.7% |
Coin flip · Chinese
n = 30 · H = 0.35 bit · uniform baseline 1.00 bit
| Answer | Count | Share |
|---|---|---|
| heads | 28 | 93.3% |
| tails | 2 | 6.7% |
Favorite number · English
n = 26 · H = 1.08 bit · uniform baseline 13.29 bit
| Answer | Count | Share |
|---|---|---|
| 42 | 21 | 80.8% |
| 7 | 2 | 7.7% |
| 1 | 1 | 3.8% |
| 2 | 1 | 3.8% |
| 5 | 1 | 3.8% |
Favorite number · Chinese
n = 29 · H = 0.43 bit · uniform baseline 13.29 bit
| Answer | Count | Share |
|---|---|---|
| 7 | 27 | 93.1% |
| 3 | 1 | 3.4% |
| 10 | 1 | 3.4% |
Random animal · English
n = 27 · H = 3.17 bit · uniform baseline 5.64 bit
| Answer | Count | Share |
|---|---|---|
| giraffe | 8 | 29.6% |
| platypus | 4 | 14.8% |
| elephant | 3 | 11.1% |
| kangaroo | 2 | 7.4% |
| zebra | 2 | 7.4% |
| panda | 2 | 7.4% |
| pangolin | 1 | 3.7% |
| capybara | 1 | 3.7% |
+ 4 more answers
Random animal · Chinese
n = 30 · H = 2.39 bit · uniform baseline 5.64 bit
| Answer | Count | Share |
|---|---|---|
| 猫 | 14 | 46.7% |
| 狗 | 6 | 20.0% |
| 狮子 | 3 | 10.0% |
| 象 | 2 | 6.7% |
| 鹰 | 1 | 3.3% |
| 企鹅 | 1 | 3.3% |
| 斑马 | 1 | 3.3% |
| 豹 | 1 | 3.3% |
+ 1 more answers
Random city · English
n = 27 · H = 4.25 bit · uniform baseline 5.64 bit
| Answer | Count | Share |
|---|---|---|
| oslo | 3 | 11.1% |
| kyoto | 3 | 11.1% |
| omaha | 2 | 7.4% |
| paris | 2 | 7.4% |
| syracuse | 1 | 3.7% |
| freetown | 1 | 3.7% |
| tokio | 1 | 3.7% |
| aurora | 1 | 3.7% |
+ 13 more answers
Random city · Chinese
n = 27 · H = 2.84 bit · uniform baseline 5.64 bit
| Answer | Count | Share |
|---|---|---|
| 东京 | 8 | 29.6% |
| 北京 | 5 | 18.5% |
| 伦敦 | 4 | 14.8% |
| 巴黎 | 4 | 14.8% |
| 赫尔辛基 | 1 | 3.7% |
| 柏林 | 1 | 3.7% |
| 罗马 | 1 | 3.7% |
| 巴塞罗那 | 1 | 3.7% |
+ 2 more answers
Random color · English
n = 30 · H = 2.48 bit · uniform baseline 4.91 bit
| Answer | Count | Share |
|---|---|---|
| teal | 14 | 46.7% |
| azure | 5 | 16.7% |
| blue | 4 | 13.3% |
| mauve | 1 | 3.3% |
| chartreuse | 1 | 3.3% |
| emerald | 1 | 3.3% |
| cyan | 1 | 3.3% |
| violet | 1 | 3.3% |
+ 2 more answers
Random color · Chinese
n = 29 · H = 1.90 bit · uniform baseline 4.91 bit
| Answer | Count | Share |
|---|---|---|
| 蓝 | 18 | 62.1% |
| 绿 | 3 | 10.3% |
| 粉 | 2 | 6.9% |
| 橙 | 2 | 6.9% |
| 紫 | 2 | 6.9% |
| 红 | 1 | 3.4% |
| 绯红 | 1 | 3.4% |
Random letter · English
n = 30 · H = 2.63 bit · uniform baseline 4.70 bit
| Answer | Count | Share |
|---|---|---|
| q | 13 | 43.3% |
| x | 6 | 20.0% |
| w | 3 | 10.0% |
| n | 1 | 3.3% |
| t | 1 | 3.3% |
| r | 1 | 3.3% |
| z | 1 | 3.3% |
| j | 1 | 3.3% |
+ 3 more answers
Random number 1-10 · English
n = 30 · H = 0.21 bit · uniform baseline 3.32 bit
| Answer | Count | Share |
|---|---|---|
| 7 | 29 | 96.7% |
| 1 | 1 | 3.3% |
Random number 1-10 · Chinese
n = 30 · H = 0.63 bit · uniform baseline 3.32 bit
| Answer | Count | Share |
|---|---|---|
| 7 | 27 | 90.0% |
| 3 | 1 | 3.3% |
| 6 | 1 | 3.3% |
| 8 | 1 | 3.3% |
Random number 1-100 · English
n = 30 · H = 1.79 bit · uniform baseline 6.64 bit
| Answer | Count | Share |
|---|---|---|
| 42 | 17 | 56.7% |
| 73 | 8 | 26.7% |
| 17 | 1 | 3.3% |
| 37 | 1 | 3.3% |
| 47 | 1 | 3.3% |
| 67 | 1 | 3.3% |
| 77 | 1 | 3.3% |
Random number 1-100 · Chinese
n = 30 · H = 2.32 bit · uniform baseline 6.64 bit
| Answer | Count | Share |
|---|---|---|
| 73 | 15 | 50.0% |
| 42 | 3 | 10.0% |
| 57 | 3 | 10.0% |
| 67 | 3 | 10.0% |
| 87 | 3 | 10.0% |
| 37 | 1 | 3.3% |
| 63 | 1 | 3.3% |
| 72 | 1 | 3.3% |
Want to verify your API really serves Gemini 2.5 Flash Lite?
Point the free fingerprint checker at your endpoint: it samples the same probe questions from your browser and compares the distributions against this reference. Your API key never leaves your browser.
Verify your endpointData source & license
Distributions: Tomáš Bruckner, "One Token Is Enough" (arXiv:2607.10252), official dataset Zenodo DOI 10.5281/zenodo.21278557, licensed CC-BY-4.0. Collected via OpenRouter at temperature 1.0 under the paper's fixed minimal one-word system prompt; answer keys are re-normalized with the checker's pipeline (color aliases, number words, coin h/t) so live probes are directly comparable.