PII Arena
HF detector

mmbert32k+cpu-int8 PII detection benchmark

Measured on 9 of 41 retained datasets under the same frozen scoring and masking protocol.

21.91%fully hidden annotations
63.70%detected / overlapped
6.87%extra masking
CPU characters / second

Strengths

Highest complete-masking rates by normalized data type.

Bank accounts & cards62.02%1,166 / 1,880
Documents & identifiers52.60%3,120 / 5,931
Passwords, keys & tokens37.95%639 / 1,684

Watch list

Lowest observed complete-masking rates; inspect before deployment.

Network identifiers1.47%277 / 18,902
Organizations5.63%257 / 4,568
Other sensitive attributes10.27%23 / 224

Language coverage

The overall leader can differ from the best choice for one language slice.

LanguageDatasetsFully hidden ↑Detected ↑Extra masking ↓
English425.70%58.42%8.55%
Russian416.19%64.84%2.22%
Multilingual150.89%67.36%

Configuration, source and version

Family
HF
Revision
d22c818cf9f2a8bfbbed8508cb417dc16a1ba3ea
Eligible datasets
9 / 41
Character F1
0.416
Untouched diagnostic
36.30% · 26,169 / 72,095
Benchmark version
1.0.3 · 2026-09-09
CPU seconds / 10k chars
Not measured
GPU seconds / 10k chars
Not measured

Results by dataset

Complete masking is primary; detection shows whether any character overlapped.

DatasetGold annotationsFully hidden ↑Detected ↑Extra masking ↓
tab-echr3,8305.93%35.22%
synth-ru-tickets32,0997.97%64.69%
ameau012,24219.45%53.93%3.41%
nym-ru9,49727.20%63.81%
nemotron-pii9,39134.33%67.85%2.25%
redmadrobot5,51634.45%60.88%2.50%
kiji-multi7,56550.89%67.36%
hivetrace1,66751.29%86.68%0.37%
secrets-issues28855.90%94.44%9.56%