internet: Style Guide Spelling Decisions (AP, Chicago, MLA, APA)

How major style guides rule on "internet"

AP lowercased 'internet' in 2016; Chicago followed in 2017. The capitalized 'Internet' is now historical.

The disagreement on "internet" is an example of capitalization conventions: the category of style-guide differences that most often confuses copy editors and creates inconsistency across long documents. Below is a guide-by-guide breakdown, drawn directly from the published editions cited.

What the divergence actually means

The shift toward "internet" largely consolidated around 2016, by which point the guides compared above had largely settled on it. Before that, editorial style on this word was unsettled, and house styles split along whether they prioritized etymological transparency or contemporary convention. The date is our own reading of when the usage consolidated, not a figure published by any of the guides.

The APA Publication Manual aligns with AP and Chicago on "internet", though APA generally addresses spelling questions only when they intersect with statistical reporting or technical psychology vocabulary. Where the manual is silent, APA defers to Merriam-Webster as its standard reference. Source: APA Publication Manual, 7th Edition

Merriam-Webster lists "internet", which serves as the lexicographic baseline for U.S. style decisions. Because Merriam-Webster's entries reflect aggregated published usage rather than editorial preference, when a guide says "follow Merriam-Webster", as APA does, that effectively delegates the call to whichever spelling has dominated the published corpus. Source: Merriam-Webster Dictionary

In our own corpus the two forms are both common enough to rank: "internet" at #928 and "Internet" at #928 by frequency, so "internet" is the more common spelling in written English and "Internet" trails it by roughly 1x in rank position. That lines up with the guides above. Frequency rank is a corpus sample, not a vote, and it says nothing about which form is correct in your house style. Source: PlainSpell corpus, Wiktionary (kaikki.org) headwords with FrequencyWords 2018 English ranks

Practical guidance for editors

For working writers, the practical rule is straightforward: in journalism, follow AP; in academic writing in the humanities, follow MLA or Chicago; in social-science publishing, follow APA; in book publishing, follow Chicago. When no house style applies, Merriam-Webster's main entry is the safest default. The differences across these guides on "internet" reflect not disagreement about correctness but different audiences and editorial pressures.

Cross-references

For the dictionary entry, frequency data, and pronunciation of internet, see the main word page. For other style-guide spelling decisions in this category, browse all style-guide spelling rulings.