What public comment actually changed — every federal rule from 2016 onward, lined up against the version its agency first proposed.
American rulemaking has a promise built into it: an agency publishes what it intends to do, the public comments, and the agency may change its mind. Whether that second step moves the text is an empirical question nobody answers, because answering it means diffing two documents for every rule. This does that — — rulemakings paired proposal-to-final, and the regulatory text of — of them compared word by word. The median rule enters the Code of Federal Regulations with — of its regulatory text new since the proposal. Most of that is small. A quarter of it is not.
Every diffed rulemaking, binned by how much of its enacted regulatory text was not in the proposal. Drag across the chart to filter everything below; click once to clear.
Each rule's enacted text split into ten equal parts, and the new words counted into whichever part they fall in, averaged over every diffed rule. If revision were spread evenly through a rule, this would be flat. It is not — the opening tenth takes the most. Read that carefully: a rule opens with its amendatory instructions (“Section 510.2 is amended by revising paragraph (a)…”), and adding one amendment anywhere rewrites that list at the top. Some of the leading peak is instruction bookkeeping rather than new obligation, and this chart cannot separate the two.
Median revision by agency, for agencies with at least 25 diffed rules. The spread is far wider than the corpus median suggests — and neither end of it is a scoreboard. An agency at the bottom may simply publish narrow, well-settled rules that were never going to move. An agency at the top may be responsive, or may just draft differently: an agency that reissues whole sections where another amends a single paragraph will measure as heavily revised on identical substance. The FCC sits far above everyone else and does exactly that. Click a row to read its rules and judge for yourself — that is what the redlines are for.
Pick a rule above. Unchanged runs are collapsed — this is the regulatory text only, not the preamble the agency wrote around it.