LaTeX Document Classes Comparison: article vs report vs book

A LaTeX document class sets the paper size, the type size, and which heading commands exist. The defaults below come from the kernel classes on 26/10/2026.

This guide is part of our Documentation Tools in 2026: Markdown, LaTeX, PDF & Printing Workflows hub. The class line is read before any package, and \chapter exists only when that class defines it.

A distribution that can compile the line is covered in the LaTeX overview and install notes. This declaration uses extarticle:

\documentclass[a5paper, 10pt, twoside, twocolumn]{extarticle}

a5paper, 10pt, twoside, and twocolumn are kernel options. extarticle comes from the extsizes bundle, together with extreport, extbook, extletter, and extproc.

The kernel classes declare 10pt, 11pt, and 12pt. extsizes adds 8pt, 9pt, 14pt, 17pt, and 20pt. With 10pt the same paper and layout options work on article:

\documentclass[a4paper,11pt,twoside]{article}

The three kernel classes are article, report, and book. classes.dtx in the LaTeX kernel is dated 2026-06-04, version 1.4n. Each class runs a fixed \ExecuteOptions list, and anything you pass in the optional argument overrides that list.

Article

article is the class for a document whose highest numbered heading is \section. It has \part, and it has no \chapter. The LaTeX cheat sheet shows \section inside a complete article skeleton.

The class executes letterpaper,10pt,oneside,onecolumn,final, and it sets \@titlepagefalse. \maketitle therefore prints the title on the first page. Pass titlepage when the title should occupy a page of its own.

The abstract environment exists. With the default (no title page, one column) it is set in \small inside a quotation. In twocolumn it is an unnumbered \section*. The page style is plain, which the class file says is defined in the format. book is the class that selects headings, and that style is the one that prints \thepage in the header.

Report

report adds \chapter and turns the title page on. \ExecuteOptions is letterpaper,10pt,oneside,onecolumn,final,openany, and the class sets \@titlepagetrue.

\maketitle uses the titlepage environment, so the title is a separate page with the empty page style. Pass notitlepage to put the title on the first page, which is what article does with its default.

openany is the chapter default. \chapter calls \clearpage, so the chapter starts on the next page, odd or even. openright switches that to \cleardoublepage, which skips to the next odd page and can insert a blank even page. The page style is plain, the same call article makes. The headings header appears on a report only after \pagestyle{headings}.

Because the title page is on, the abstract environment is placed on a title page of its own, vertically centered, with \abstractname in bold. That is the \if@titlepage branch in classes.dtx. The environment is defined for article and report only.

Book

book is the class for a document that is printed on both sides and divided into front matter, main matter, and back matter. \ExecuteOptions is letterpaper,10pt,twoside,onecolumn,final,openright. The title page is on, as in report, and \chapter is defined.

openright means each chapter starts on a recto page. twoside makes the inner and outer margins differ, and it selects the two-sided form of the headings page style. In that definition the footer is empty. An even page has \thepage on the left of the header and \leftmark (the chapter) on the right. An odd page has \rightmark (the section) on the left and \thepage on the right.

The first page of a chapter runs \thispagestyle{plain}, so that page does not use the headings header.

\frontmatter, \mainmatter, and \backmatter exist only in book. \frontmatter issues \cleardoublepage, turns chapter numbering off, and switches to roman page numbers. \mainmatter clears to a double page, turns chapter numbering on, and restarts arabic numbering at 1. \backmatter clears the page, using a double page when openright is set, and turns chapter numbering off without resetting the page counter.

\cleardoublepage in \frontmatter and \mainmatter is unconditional in the current source. The openany alternatives next to those two commands are commented out.

What differs

14pt is not a declared option, so article keeps the 10pt it executed and passes 14pt on as a global option. The extsizes classes are the ones that declare 14pt, 17pt, and 20pt.

Paper, type size, and sides

classes.dtx declares these paper options. landscape swaps the two dimensions after the size is set.

TeX Live and MiKTeX ship these defaults as they are. letterpaper remains the paper until the file passes a4paper. a5paper is 148mm by 210mm, the stock size for an A5 insert such as the Filofax bill-tracker pages, which are printed as a booklet.

oneside and twoside exist on all three classes. onecolumn is the default, and twocolumn is the alternative. openright and openany are declared only for report and book. On article they are unused global options, because there is no \chapter for them to move.

titlepage and notitlepage flip \if@titlepage. leqno loads leqno.clo (equation numbers on the left). fleqn loads fleqn.clo (displays flush left). draft sets \overfullrule to 5pt so overfull boxes draw a rule. final sets that rule to 0pt and is already in the default list.

Tagged PDF

For article, report, and book, tagging is turned on with \DocumentMetadata before the class. The November 2025 LaTeX release made the old testphase key obsolete. \DocumentMetadata now loads the tagging modules, and tagging=on enables tags. The tagging project’s usage notes give this shape:

\DocumentMetadata{
  lang = en,
  pdfstandard = ua-2,
  tagging = on
}
\documentclass{article}

Frank Mittelbach’s TUGboat 47:2 (2026) paper on accessible classes describes article, report, and book as classes whose semantic elements have been made accessibility-aware through low-level interfaces. A template rewrite of those classes is still outstanding. Ulrike Fischer’s paper in the same issue records that testphase is obsolete and that the tagging key is the switch.

Slide files that start with \DocumentMetadata and then load beamer hit a class error. Beamer 3.78, class date 2026/08/20, raises ClassError with the text “The beamer class is not compatible with \DocumentMetadata” and names ltx-talk as the class for tagged output. That error was added in 3.77 (2026-01-22). Version 3.78 adds left triangle itemize and bibliography templates and keeps the error.

KOMA-Script

KOMA-Script 3.49.3 is dated 2026-10-19. The classes that replace the kernel ones are scrartcl, scrreprt, and scrbook. scrlttr2 is the letter class. scrarticle and scrreport are wrappers, and the bundle README says to load scrartcl rather than scrarticle.

The guide’s defaults differ from article on two points. Paper is A4 in portrait, and fontsize=11pt is the default for scrartcl, scrreprt, and scrbook, where the kernel default is 10pt. Renaming the class and leaving the option list empty switches a 10pt letter document to 11pt A4.

fontsize accepts a size with a TeX unit, and a bare number is read as pt. Changing it after the class is loaded leaves the type area as it was. \recalctypearea rebuilds it, and the same command follows a later paper change. The guide forbids fontsize inside a paragraph.

scrkernel-typearea.dtx executes twoside=true for scrbook and twoside=false for the other classes. With twoside=semi, the guide puts the binding correction on the left margin of both pages. Title pages are the default for scrbook and scrreprt. scrartcl uses an in-page title.

Chapters in scrreprt start on the next page (open=any). Chapters in scrbook start on the next right-hand page (open=right). chapterprefix=false is the default, so the chapter title is a single line. report and book put the word “Chapter” on a line of its own. chapterprefix=true does the same on KOMA-Script.

The 3.49.3 preface says deprecated options produce a warning, and deprecated commands produce an error. noheadsepline, cited there as obsolete for twenty years, is one of the warnings. The documented switch is headsepline. Setting it true, or giving it with no value, draws a rule under the header. Deactivating it removes the rule.

From 3.50 the preface says those warnings go away, and the version option will no longer restore the old settings. Tagging was postponed in 3.49.3. The preface says \DocumentMetadata support missed this release, and CTAN lists scrartcl as incompatible with tagged PDF.

\documentclass[fontsize=10pt]{scrreprt}

fontsize=10pt is the option that keeps the kernel type size. paper=a4 can be omitted, because A4 is already the KOMA-Script default.

Memoir

memoir 3.8.4b is dated 2025/11/04. The manual’s chapter on class options states that twoside is the default. The article option changes chapter behaviour so that a new chapter does not necessarily start a new page. Base type-size options are 9pt, 10pt, 11pt, 12pt, 14pt, 17pt, 20pt, 25pt, 30pt, 36pt, 48pt, and 60pt. The *pt option is an author-defined size and needs a .clo file named from \anyptfilebase and \anyptsize, both set before \documentclass.

extrafontsizes, together with outline fonts, extends the relative sizes past the bitmap limit. On the 60pt option the manual’s size table lists \HUGE at 132pt. Without extrafontsizes, \huge, \Huge, and \HUGE stay at \LARGE for the 14pt option, and a bitmap \HUGE is limited to 25pt.

CTAN’s class description says memoir provides the functionality of over thirty of the more popular packages. Since version 3.8 the manual says some of those are loaded as packages rather than copied into the class. booktabs moved that way in 2023.

Tagging through \DocumentMetadata is not available in this release. Tagging-project issue 1040 (2025-11-04) records that memoir is incompatible with the code that command loads, and the reply there is that tagging work is not underway. PDF management without tagging, as given in that issue, is:

\RequirePackage{pdfmanagement}
\SetKeys[document/metadata]{lang=en}
\documentclass{memoir}

Presentations, IEEE, and the small kernel classes

beamer puts slide content in frame. For a tagged PDF, ltx-talk 0.6.10 (2026-10-13) is the class CTAN describes as experimental, with tagging ahead of design, and it needs a LaTeX format from 2025-11-01 or later. Beamer theme files are not ltx-talk themes. The manual’s tagging section uses this preamble:

\DocumentMetadata{tagging=on, pdfstandard=ua-2}
\documentclass{ltx-talk}

ltx-talk also uses frame. The manual tags a frame title as a heading at level H4, under section and subsection, and it says some accessibility checkers warn about that level.

IEEEtran 1.8b is dated 2015/08/26 in \ProvidesClass. \documentclass[journal]{IEEEtran}, [conference], and [technote] are the publication forms the class declares. compsoc is the Computer Society variant. CTAN lists the class as incompatible with tagged PDF.

Three more kernel classes sit beside article. proc passes twocolumn to article and redefines abstract as \section*{\abstractname}. minimal, dated 2001/05/25 in its \ProvidesClass line, sets \normalsize to 10pt on 12pt leading, \textwidth to 6.5in, and \textheight to 8in, and it defines no sectioning. It is a test class. letter is the kernel correspondence class. standalone crops the page to the typeset box, which is how a diagram is compiled to its own PDF and then included in another document.

When the layout is not what you asked for

An undefined \chapter means the loaded class has no chapters. report or book is the kernel class that defines the command. A blank even page before each chapter is openright, the book default. openany starts the chapter on the next page.

US Letter output from article, report, or book is letterpaper. Add a4paper. After a rename to scrreprt or scrbook, A4 is already in force and the type size is 11pt. fontsize=10pt keeps the previous measure.

On KOMA-Script 3.49.3, replace a noheadsepline warning with headsepline=false, or with headsepline when the rule should be drawn. A deprecated command is an error in this release. When the log says the type area was left unchanged, call \recalctypearea after the paper or fontsize assignment.

If beamer stops on \DocumentMetadata, remove that line to keep the current slides, or compile with ltx-talk when the PDF has to be tagged. memoir 3.8.4b and KOMA-Script 3.49.3 are outside the tagging setup documented for article, report, and book.

Stay with article for a sectioned document. Step up to report or book when a chapter has to start a page, and step outside the kernel when the job is a calculated type area, a type size past 12pt, or a tagged slide file.

Useful links

• Converting LaTeX to Markdown – Tools & Workflows