Patent Classification · CPC Guide
What do CPC codes mean?
The Cooperative Patent Classification (CPC) organizes all patents into a hierarchical taxonomy. Every patent is assigned one or more codes that say what technology it covers. Section A–H, then classes, subclasses, groups, and subgroups.
Patents with CPC codes
1,362
CPC coverage
100% of DB
Largest section
G — Physics
CPC Sections A–H — Patent Volume
Each section covers a major branch of technology. A patent may have codes from multiple sections.
Physics
Instruments, optics, computing, information storage, semiconductors
617
34.6%
Human Necessities
Agriculture, food, personal articles, health, amusements
348
19.5%
Electricity
Electric elements, circuits, communications, power transmission
343
19.2%
Performing Operations
Separating, mixing, shaping, printing, transporting
216
12.1%
Chemistry & Metallurgy
Chemical compounds, compositions, metallurgy, materials
192
10.8%
Mechanical Engineering
Engines, pumps, weapons, lighting, heating, blast & explosives
49
2.7%
Textiles & Paper
Yarns, fabrics, paper, cellulose, fibres
9
0.5%
Fixed Constructions
Building, mining, drilling, earthworks
9
0.5%
Top 30 CPC Subclasses
A subclass is 4 characters: one letter (section) + two digits (class) + one letter (subclass). E.g., G06F = Physics · Computing · Electronic Digital Data Processing.
Computing (general)
Pharmaceutical Preparations
Data Communication
AI & Neural Networks
Business Methods
Medical Diagnosis/Surgery
Peptides
Drug Therapeutic Activity
Microorganisms/Genetic Engineering
Pictorial Communication
Electrochemical Processes (Batteries)
Optical Elements
Image Processing
Chemical/Physical Analysis
Radio Transmission
Wireless Communication
Graphical Data Reading
Static Memory
Image Recognition
EV Propulsion
How to read a CPC code
G
Section
Physics
06
Class
Computing
F
Subclass
Elec. Digital
16
Group
Info Retrieval
/9035
Subgroup
Ranking
The full code G06F16/9035 means: Physics (G) → Computing (06) → Electronic Digital Data Processing (F) → Information Retrieval (16) → Ranking algorithms(/9035). Google's PageRank patent (US6285999) has exactly this code.
Why section G dominates
CPC section G (Physics) contains G06F (computing) and G06N (AI), the fastest-growing areas of modern technology. Most software, computing, and AI patents land here — which is why G dwarfs sections like D (textiles) or E (construction).
Multiple codes per patent
A single patent typically receives 3-15 CPC codes. A smartphone camera patent might get codes from H04N (pictorial communication), G06T (image processing), AND G02B (optical elements). The counts above count distinct patents — not code-patent pairs.
CPC vs. IPC vs. USPC
CPC (Cooperative Patent Classification) is the modern standard, jointly maintained by USPTO and EPO. It replaced the older USPC (US Patent Classification) in 2015. IPC (International Patent Classification) is the international standard — CPC is a superset of IPC with more granular subgroups.