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PatentBrief

Original data · The Public-Domain Index

83 landmark patents are now free to build on.

69% of the 121 patents PatentBrief explains have entered the public domain — their protection has lapsed, so anyone can use, manufacture, and build on the invention without a license. Below: the most-cited, ranked.

Methodology

Computed directly from the PatentBrief database. A patent counts as public domain when its status is expired or its term has run (US utility patents last ~20 years from filing). “Times cited” is the forward-citation count — the number of later patents that build on it — our proxy for influence. Every figure on this page is derived from the underlying records, not estimated.

Most influential inventions now in the public domain

Ranked by times cited
#PatentGrantedTimes cited
1How to Make Many Copies of a Specific DNA SegmentCetus Corp19876,227
2How Touchscreens Detect Multiple Finger Presses at OnceApple Inc20101,995
3Inkjet Printing — How a Hot Wire Discovered the Bubble JetCanon Inc19881,806
4How Amazon's One-Click Online Ordering System WorksAmazon com Inc19991,635
5How Touchpads Detect Two Fingers for Mouse Clicks and DragsLogitech Inc19981,577
6How the iPhone's Slide-to-Unlock Gesture WorkedApple Inc20101,267
7How a Web Server Distributes Requests for Different Web PagesResonate Inc19981,148
8How RSA Public-Key Encryption Secures Digital MessagesMassachusetts Institute of Technology19831,015
9How Online Stores Suggest 'You Might Also Like' ProductsAmazon com Inc2001899
10How to Visually Search Databases Using Venn-like DiagramsIndividual1999859
11How Websites Get Ranked by Counting Links and Their ImportanceLeland Stanford Junior University2001817
12How Early Online Services Delivered Applications Using Networked 'Objects'Prodigy Services Co1994808
13How Computers Agree on a Secret Code Without Meeting FirstLeland Stanford Junior University1980708
14OncoMouse — The First Patented Animal, Built to Get CancerHarvard University1988643
15Microsoft's Browser Patent — At the Center of the Biggest Antitrust Case in TechUniversity of California San Diego UCSD1998577
16Speeding Up Web Access on Slow Wireless NetworksBell Communications Research Inc1997546
17The HTTP Cookie — How Websites Remember Who You AreNetscape Communications Corp1998508
18Making Antibody-Like Proteins in a Single ChainEnzon Labs Inc1995440
19Nylon — The First Synthetic Fiber, Invented at DuPontEI Du Pont de Nemours and Co1938430
20How Netscape's SSL Encrypted Web Connections WorkNetscape Communications Corp1997383
21How LEGO Bricks Connect and Stay TogetherInterlego AG1961374
22How Computers Shrink Data Using a Dynamic DictionarySperry Corp1985347
23How to Make Hybrid DNA and Grow It in MicrobesLeland Stanford Junior University1980346
24How Flash Memory Stores Multiple Bits in One CellToshiba Corp1999326
25How Modified RNA Teaches Cells to Make New ProteinsUniversity of Pennsylvania Penn2012322

Public domain by decade granted

  • 1870s1
  • 1880s1
  • 1900s1
  • 1910s1
  • 1930s2
  • 1940s1
  • 1950s5
  • 1960s4
  • 1970s10
  • 1980s13
  • 1990s23
  • 2000s16
  • 2010s5

Leading fields now free to build on

  • telecommunications17
  • consumer_electronics15
  • semiconductors7
  • software7
  • biotech5
  • automotive4
  • ecommerce3
  • materials-science3
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