The data picked UHF in 2002. Walmart started tagging jeans with it eight years later.
Two kinds of RFID tag competed to label single items. HF tags talk to the reader through a coil at close range, like a contactless card. UHF tags bounce the reader’s radio wave back and are read from metres away, many at a time. For each we measured how much better per dollar it got each year, using only the patents that existed at the time.
% better per dollar each year. One reading a year.
In 2002 UHF was getting about 65% better per dollar every year, HF about 46%. UHF has stayed ahead at every reading since. HF held at about 40 to 50% a year for two decades, the pace of a technology that had already matured.
HF read well near liquids and metal, but only within about a metre, so each item had to come to the reader. UHF read from about ten metres and around 200 tags at once, against about 50 for HF, so a whole rack or a sealed carton could be counted in one pass.
Our data: UHF improving 1.4 times as fast as HF.
The UHF industry standard, EPC Gen2, is agreed.
A benchmark calls HF the winner for single items “by a technical knockout”. The same day, Avery Dennison, Walmart and Impinj back UHF in public.
Walmart starts tagging men’s jeans and basics with UHF tags, expecting 250 million items a year or more.
Avery Dennison buys Smartrac’s RFID inlay business for about $255 million.
52.8 billion UHF tag chips ship worldwide.
It would not have said when retailers would roll tags out, or which one would go first. It would have said the tag on the retail item would be UHF, four years before a benchmark still called HF the winner.
For a label maker, that is the window to decide which tag to build inlay lines for. Avery Dennison made that call in public in 2006, while the experts still disagreed.
UHF still leads, by a narrower margin than in the 2000s. The same reading works for the next tag question: whether, and when, battery-free Bluetooth catches up with UHF RAIN tags.
TIR — the Technology Improvement Rate — measures how fast a technology gets better each year, computed from global patent data. Not who is filing, or how much: how fast the route is actually moving. Historically, the fastest-improving technology always wins.
Provenance. Every patent carries a publication date, so the record can be replayed: every improvement rate on this page uses only the patents that were published at the time. Chart data: GetFocus platform exports, October 2026.
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