Lesson 5 of 8

Figures and Images: Including, Sizing, and Captioning

~8 min read

By the end of this lesson you can insert an image, scale it, give it a caption and label, position it, and refer to it by number. Load graphicx, then use \includegraphics inside a figure environment.

Loading graphicx and inserting an image

Add \usepackage{graphicx} to the preamble, then place the image with \includegraphics. Upload the image file into your project so LaTeX can find it.

\usepackage{graphicx}   % in the preamble
% ...
\includegraphics[width=0.8\linewidth]{diagram.png}

Sizing options

Option	Effect
width=0.8\linewidth	Scale to 80% of the text width
width=5cm	Fixed width of 5 cm
height=4cm	Fixed height
scale=0.5	Scale to 50% of natural size
angle=90	Rotate 90 degrees

The figure environment: captions and labels

Wrap the image in a figure environment to add a numbered caption and a label you can reference. \centering centers it.

A complete, referenceable figure

\begin{figure}[ht]
  \centering
  \includegraphics[width=0.8\linewidth]{diagram.png}
  \caption{System architecture overview.}
  \label{fig:arch}
\end{figure}

As shown in Figure~\ref{fig:arch}, the system has three layers.

The ~ in Figure~\ref{...} is a non-breaking space. It keeps “Figure” and the number together on the same line.

Placement: where figures land

The optional [ht] is a placement hint, LaTeX floats figures to a convenient spot. Common specifiers:

h, “here”, approximately where written
t, top of a page
b, bottom of a page
p, a dedicated page of floats
!. Try harder to honor your request (e.g. [!ht])

For an image that must appear exactly where written, load \usepackage{float} and use [H].

Supported formats

pdflatex accepts .png, .jpg, and .pdf. Vector graphics (PDF) stay crisp at any size, prefer them for diagrams and plots.

Frequently asked questions

My image does not appear. Why?

Check that the file is uploaded to the project, the filename matches exactly (case-sensitive), and graphicx is loaded. The LetX file browser shows what is available to include.

How do I put two images side by side?

Use two \includegraphics inside one figure, or the subcaption package with subfigure environments for individually captioned panels.

How do I force a figure to stay in place?

Load \usepackage{float} and use the [H] specifier: \begin{figure}[H]. This disables floating for that figure.