Why do web paragraphs break, while print paragraphs indent?

Question

Both indentations and line breaks create a strong disruption that signals "this is a new paragraph" to the user.

Question: Several decades into web browsers becoming a major form of communication, web browsers use new lines for each paragraph, while printed books and magazines still use indentations. Certainly e-books are often printed as paper-books, and printing houses want to save paper by condensing the number of pages printed. Why wasn't the <p> tag developed to also use an indentation?

Author Erika Hall on Medium, using line-break paragraphs:

Author Erika Hall in her e-Book, Just Enough Research:

Answer 1

Practically almost all the typographic rules that are followed today are not a recent invention, most of them come from the first reunification of criteria regarding the book design and composition back in the 18th century.

These rules are innumerable, among them the indentation for the paragraph break. On pages with several text columns, the graphical way of showing that a paragraph ended giving way to the next is a blank space regularly defined by m-quads = a block the same width and height as the font size and without print relief. Once printed this empty space also serves to make the reading more relaxing.

It was also a way for the typesetter to follow a certain rhythm while assembling the page in a metallic type form, where he/she not only had to place letter by letter manually, but also had to do it the other way around. All typographic blanks are guidelines to better understand and follow the page composition.

_{Image source Wikimedia.org}

In web pages it is rare to find these spaces and other typographic rules applicable to the printed edition because it is unlikely:

• Find endless texts like in a book
• Have long paragraphs arranged in two or more columns

On the other hand, a book or page has physical limits, the page itself or the amount that should be in a book, while a website has no those limits. On many web pages, paragraph breaks don't need indentation because they usually use another resources like adding an empty line as a space between paragraphs:

Answer 2

Good question. I can think of two reasons.

First, print has limited space. An indentation takes much less space than a lead. The need to save space due to the cost of paper was such that the earliest printed books had indentations, and very small ones indeed. Handwritten books rarely broke paragraphs at all and the earliest ones that did break paragraphs used a symbol instead of a line break at all. It's so dense. On the Internet, of course, vertical space is of almost no concern. You can insert whole leads with impunity, and make font sizes relatively large and tracking relatively wide, to aid reading.

The other consideration is a technological one. Again, on computers vertical space is easy, but horizontal space is hard. In the early days, you had only 80 characters per line; this limitation is still followed by many style guides and still makes indentation feel like it's stealing space when coding.

Also, somehow the community never seems to have come to an agreement about how to implement it -- even today we argue about spaces vs tabs. There is a \t tab character but it's impossible to predict how it will be displayed cross-platform. HTML does have the <p> paragraph tag and CSS has the widely and early adopted text-indent property, but I suppose by then it was already late in the game for establishing digital typesetting conventions. I've only seen it used to try and faithfully reproduce print layout on magazine websites and whatnot.