"Home page" was used first, but "homepage" followed soon after, is also acceptable and I prefer.

  • Homepage was used to refer to the main page of a website as early as July 1993.

  • Home page was used to refer to the main page of a website as early as September 1992.

    • The first web browser was only written (by Tim Berners-Lee) in 1990-1991.
  • Home page was used to refer to the main page of a HyperCard system as early as March 1991.

    • HyperCard was a successful hypermedia forerunner to the WWW.

Style guides

These style guides use homepage:

  • The Guardian

  • IEEE Computer Society

  • Apple (PDF)

  • Yahoo (.docx)

  • International Reading Society

  • American Psychological Association

These style guides use home page:

  • MIT's Office of Communications and Donor Relations

  • Garbl's Editorial Style and Usage Manual

  • Better Homes and Gardens Stylebook

(More style guides here.)

homepage

The OED has home page from August 1993, and homepage from 1997, however I found homepage in Usenet as early as July 1993.

The first uses both homepage and home page in the same paragraph.

12th July 1993 - sci.astro.hubble - "NASA's Project STELAR announces WWW server for public access" - Archie Warnock:

I am also collecting WWW homepage documents with the intention of making them available through WAIS, as an experiment in combining the search functionality of WAIS with the display and hypertext capabilities of WWW and Mosaic. If you run a WWW server and would like your home page included in this database, just mail the HTML file to me.

The next, from the next day, uses Homepage.html as a filename and also as a standalone noun.

13th July 1993 - comp.infosystems.www - "A possible feature for WWW Options" - Jonathan B. Marder:

What I would like to see is a "tree" of documents visited which shows not only the URLs but also how the document was called. e.g.:-

Homepage.html |---> URL-1 -----> URL-1a 
              | 
              \---> URL-2 -----> URL-2a 
                        | 
                         \----> URL-2b 

...and so on. This would be added to throughout the session. Actually, it would be nice if the user could edit in some annotation and save it for use as a future homepage.

home page

Home page can also be antedated in Usenet. The earliest computing use I found is in reference to HyperCard. According to Wikipedia:

HyperCard was an application program and programming tool for Apple Macintosh and Apple IIGS computers, that was among the first successful hypermedia systems before the World Wide Web.

18th March 1991 - rec.radio.amateur.misc - "Hypercard HamStack Articles Part 2 of 8" - Diana L. Syriac:

If you are using recent ham stacks (Novice and Tech v3.0 or greater or General, Advanced, Extra v2.0 or greater), AND you have not yet entered the Ham Stacks (ie, you're still on the Home page), there's an easier way to get started that is faster (this option stops the automatic random generation of a test).

The first WWW use I found is from the following year.

11th September 1992 - talk.politics.misc and talk.bizarre - "Voice: Issue #1 Out!" - Tom Boutell:

The first issue, which deals with abortion and specifically with the Roe vs. Wade U.S. Supreme Court decision's legacy, is now available by the following means:

[...]

  • On the World Wide Web hypertext system (soon). This is a wonderful way to read the magazine, but I haven't heard from the web's maintainer in approximately a month. (If you already use it and are comfortable with making your own links from home pages of your own, write to me and I'll give you the necessary information to link to the magazine.)

Home page vs homepage falls into the same category as website and Web site as well as motor home and motorhome. Originally, the words homepage, website, and motorhome did not exist, but after so much usage over the years it has become acceptable to combine the two words into one.

In other words, either way is fine.


The poster mentions Merriam-Webster's in a comment responding to Hugo's excellent answer:

It's also interesting that none of the answers referred to Merriam-Webster's, which uses home page. I thought it's considered an authoritative source of English language, besides the OED.

I should note first that MW lists words as it finds them: When compiling and updating a dictionary for publication, it identifies what it perceives to be the preponderant spelling of a particular word among the published sources it has collected that use the term; subsequently it alters that spelling to match reality if conditions change in the wild world of actual usage. So while it may be authoritative in some sense, MW isn't committed to a particular spelling when popular usage goes a different way.

To my knowledge, home page debuts in the 1999 printing of Merriam-Webster's Collegiate Dictionary, Tenth Edition; it doesn't appear in the 1997 printing of the same edition. In 1999, most publications (including the computer magazines where I work) used the two-word spelling. More recently, however, homepage has become increasingly common. Our magazines made the switch from home page to homepage within the past two years—and we are by no means early adopters of streamlined spellings of technology terms.

Elsewhere, the American Heritage Dictionary of the English Language, Fourth Edition (2000) gives the spelling as "homepage or home page," with the closed-up spelling in the position of precedence.

I'll be surprised if the next edition of Merriam-Webster's Collegiate Dictionary (the Twelfth) doesn't include both home page and homepage as common alternative spellings. And in the long run, as people grow accustomed to seeing (and instantly recognizing the meaning of) the character string homepage, I expect the closed-up spelling to push the two-word spelling toward obsolescence.


Update (January 11, 2021)

More than seven and a half years later, there is still no Merriam-Webster's Twelfth Collegiate—and the online version of Merriam-Webster's dictionary has not altered its treatment of the spelling of home page to reflect the fact that the spelling homepage is quite common.

Nevertheless, real-world usage has shown a considerable drop in the advantage home page enjoys over homepage in relative frequency of appearance in books and peridicals. Here is the Ngram chart for "home page" (blue line) versus "homepage" red line) for the period 1980–2019:

As the chart indicates, the frequency of "home page" in 2013 was slightly more than twice that of "homepage" (0.0001189248% to 0.0000511119%), but in 2019 that advantage had fallen to less than than half again as much (0.0000610258% to 0.0000383980%)—and this change in frequency has occurred despite Merriam-Webster's continuing refusal to acknowledge that homepage has become a very common variant spelling of the term.