Your first document

Your first LaTeX document

LaTeX lets you make beautiful documents — reports, books, and especially maths.
You write plain text with commands, and the computer turns it into a polished PDF.
Your LaTeX is compiled on our server — press Run and the PDF appears next to your code.

$You write main.tex, our server compiles it, and a PDF comes out$

The shape of every document

Every document has two parts — a preamble and a body:

\documentclass{article}
\begin{document}
Hello, world!
\end{document}

\documentclass{article} is the preamble: it sets the kind of document.
Everything between \begin{document} and \end{document} is the body — the part that actually appears in the PDF.

$Every document has a preamble (the setup) and a body (what appears)$

Now you try

Below is a document skeleton. Add a greeting in the body.
Press Run to compile it and see the PDF, then Check when you think it is right.

Common mistakes

A document needs \documentclass{...} and a \begin{document} ... \end{document}.
The text you want to see goes inside the document environment.

The skeleton below is a complete LaTeX document. Replace the comment in the body with a greeting (any text containing the word Hello), then click Run to compile it and see the PDF.

\documentclass{article}
\begin{document}
% Replace this comment with a greeting.
\end{document}

Click Run to compile and preview the PDF.

Options in square brackets change the whole document. Make the text bigger by adding the [12pt] option: \documentclass[12pt]{article}. Run and see every letter grow.

\documentclass{article}
\begin{document}
This text looks a little small at the default size.
\end{document}