What Is Overleaf? How to Use the Online LaTeX Editor (2026 Guide)

Overleaf is an online LaTeX editor that runs in your browser. You write LaTeX source on one side of the screen, Overleaf compiles it on its servers, and the finished PDF appears on the other side, with nothing to install. Several people can edit the same project at once, which is why it is the standard tool for papers, theses, CVs and technical reports written in LaTeX.

This guide explains what Overleaf is, how it relates to LaTeX, what the free plan includes, and how to create and organise your first project. It also covers templates, collaboration, Git and GitHub sync, the errors beginners hit most often, and the alternatives. The plan limits come from Overleaf’s own documentation, and the example project was compiled and checked before publishing.

What Is Overleaf?

Overleaf is a web-based, collaborative LaTeX editor. It bundles three things that normally take an afternoon to set up on your own computer: an editor with LaTeX syntax highlighting and autocomplete, a full TeX Live distribution with thousands of packages, and a PDF viewer that updates when you recompile.

• Who makes it: John Hammersley and John Lees-Miller started it in 2011 (originally as WriteLaTeX). It became part of Digital Science in 2014 and merged with its rival ShareLaTeX in 2017.
• Who uses it: Overleaf says it has more than 30 million users, mostly students, researchers and engineers, plus a growing number of technical writers and job seekers using its CV templates.
• Is it open source? Yes. The code behind Overleaf is published on GitHub under the AGPL-3.0 licence as Overleaf Community Edition, which you can host yourself. The hosted site at overleaf.com and the paid Server Pro edition add features on top.

If you searched for the meaning of the word: “overleaf” is an ordinary English word meaning “on the other side of the page”, as in “see the table overleaf”. In tech it almost always refers to the LaTeX editor.

Overleaf vs LaTeX: What Is the Difference?

People often say “I wrote it in Overleaf” and “I wrote it in LaTeX” as if they were the same thing. They are not:

So Overleaf uses LaTeX; it doesn’t replace it. Everything you learn in Overleaf (document classes, packages, environments) works in any other LaTeX setup, and a project downloaded from Overleaf as a .zip compiles locally. If you are new to the language itself, start with how to write in LaTeX.

Is Overleaf Free?

Yes. The free plan has unlimited projects and access to the whole template gallery. The paid plans (Student, Standard and Pro, plus group and organisation licences) mainly buy you more compile time, more collaborators and the team features. According to Overleaf’s plan-limits page:

Prices are shown in your local currency and vary by country, so check the Overleaf plans page for the current figure. Before paying, check whether your university or employer already has an institutional licence; many do, and you get premium features by confirming your institutional email.

The 10-second compile limit is the one free users notice. Short papers and CVs compile well within it; a long thesis with many high-resolution images or TikZ diagrams may not. The section on errors below covers how to bring compile time down before you consider upgrading.

How to Use Overleaf: Step by Step

1. Create an account at overleaf.com with an email address or an institutional or Google login.
2. Start a project. Click New project and choose a blank project, an example project, a template, or an import. Overleaf can import a .zip of an existing LaTeX project, a GitHub repository (premium), and even a Word (.docx) or Markdown file, which it converts to LaTeX with Pandoc. Converted tables, figures and citations usually need tidying.
3. Learn the three panes. The file tree is on the left, the editor in the middle and the PDF on the right. The editor has a Code Editor mode for raw LaTeX and a Visual Editor mode that hides most of the markup, which helps collaborators who don’t know LaTeX.
4. Write and recompile. Press Recompile (or Ctrl/Cmd + Enter) to rebuild the PDF. Click in the PDF to jump to the matching source line, and the other way round.
5. Check the main document and compiler. Each project compiles one main .tex file. In the project settings you can change it, choose the TeX Live version, and switch the compiler between pdfLaTeX (the default), LaTeX, XeLaTeX and LuaLaTeX. Use XeLaTeX or LuaLaTeX if you need system fonts or a lot of Unicode.
6. Download or share. Download the PDF, or the whole project as a .zip, or share the project with collaborators.

Your First Overleaf Project, Organised Properly

A single long main.tex becomes hard to manage after a few pages, especially with more than one author. Split the project from the start:

first-project/
├── main.tex              % preamble + document structure
├── refs.bib              % bibliography entries
├── sections/
│   └── introduction.tex  % one file per section or chapter
└── figures/
    └── latency.png

main.tex holds the preamble (document class and packages) and pulls in each section with \input:

\documentclass[11pt]{article}
\usepackage[margin=1in]{geometry}
\usepackage{amsmath}
\usepackage{graphicx}
\usepackage{booktabs}
\usepackage[hidelinks]{hyperref}

\title{Measuring API Latency}
\author{Your Name}
\date{\today}

\begin{document}
\maketitle

\input{sections/introduction}

\section{Results}
The median latency fell from 180\,ms to 95\,ms after caching
(Table~\ref{tab:latency}, Figure~\ref{fig:latency}).
We report the 95th percentile as
\begin{equation}
  p_{95} = \min\{\, x : F(x) \ge 0.95 \,\}
  \label{eq:p95}
\end{equation}
where $F$ is the empirical distribution of response times.

\begin{table}[h]
  \centering
  \begin{tabular}{lrr}
    \toprule
    Endpoint & Before (ms) & After (ms) \\
    \midrule
    /search  & 180 & 95 \\
    /profile & 120 & 70 \\
    \bottomrule
  \end{tabular}
  \caption{Median latency before and after caching.}
  \label{tab:latency}
\end{table}

\begin{figure}[h]
  \centering
  \includegraphics[width=0.6\textwidth]{figures/latency.png}
  \caption{Median latency per endpoint.}
  \label{fig:latency}
\end{figure}

\bibliographystyle{plain}
\bibliography{refs}
\end{document}

sections/introduction.tex contains only content, so co-authors can each own a file:

\section{Introduction}
Caching is one of the cheapest ways to cut response times \cite{fielding2000}.
This report compares two endpoints before and after adding a cache.

refs.bib holds the bibliography in BibTeX format. Reference managers such as Zotero and Mendeley can export (or, on premium plans, sync) this file for you:

@phdthesis{fielding2000,
  author = {Roy Thomas Fielding},
  title  = {Architectural Styles and the Design of Network-based Software Architectures},
  school = {University of California, Irvine},
  year   = {2000}
}

I compiled this exact project locally with Tectonic 0.17 (a self-contained TeX engine) to check it: it built cleanly with no warnings, and every cross-reference and the citation resolved. You can upload the same files to Overleaf as a .zip. Here is page 1 of the result:

A few habits from this example that pay off in every project:

• Label everything you refer to (\label{tab:latency}) and use \ref. Numbers update automatically when you add or move a table.
• Use booktabs (\toprule, \midrule, \bottomrule) for clean tables without vertical lines.
• Load hyperref with hidelinks if you don’t want coloured boxes around links in the PDF. Without the option, my first build had red and green boxes around every reference.
• Keep images in a folder and size them relative to the text width, as in width=0.6\textwidth.

Overleaf Templates

The Overleaf template gallery is one of the main reasons people sign up. It includes:

• Journal and conference templates from publishers such as IEEE, ACM, Springer and Elsevier, set up with the required formatting. Many journals let you submit directly from Overleaf.
• Theses and dissertations, often provided by the universities themselves.
• CVs and resumes, which are among the most popular templates on the site.
• Presentations built with Beamer, plus posters, letters, reports and lab notebooks.

Opening a template creates a copy in your account, so you can’t break the original. Read the template’s licence before reusing it outside Overleaf; most are permissive, but not all.

Collaborating in Overleaf

• Sharing: invite people by email, or turn on link sharing with separate view-only and edit links. On the free plan you can invite one collaborator per project.
• Real-time editing: everyone edits the same files at once and sees each other’s cursors, so there are no merge conflicts inside Overleaf.
• Comments and chat: highlight text to leave a comment thread, or use the project chat.
• Track changes (premium): edits appear as suggestions that the owner can accept or reject, like suggestion mode in Google Docs.
• History: free users can see and restore the last 24 hours; premium users get the full history and can label versions, for example “submitted draft”.

For technical writers, this is the main difference from a local LaTeX setup: reviewers can comment in the document without installing anything or learning Git. The same review habits from version control for documentation still apply.

Git, GitHub and the Overleaf API

Overleaf has two Git options, both premium on overleaf.com:

• Git integration: every project has a Git remote. Clone it, edit in your own editor, then push and pull. Overleaf recommends keeping projects under about 100 MB when you use Git.
• GitHub synchronization: link a project to a GitHub repository and push or pull between them from inside Overleaf.

There is no general public API for editing existing projects. What Overleaf calls its API is the “Open in Overleaf” feature: a website can send a .tex file or a zipped project to Overleaf, which opens it as a new project for the visitor. The simplest form is a link:

https://www.overleaf.com/docs?snip_uri=https://example.com/paper.tex

For automation, such as building PDFs on every commit, use the Git integration and compile in CI with your own TeX installation.

Common Overleaf Errors and How to Fix Them

Compile timeout

On the free plan, a compile that takes longer than 10 seconds stops with a timeout. Overleaf’s own troubleshooting steps, in order:

1. Turn on Stop on first error in the Recompile menu and fix errors one by one; a pile of errors can stall the build.
2. Compile in Fast [draft] mode, which replaces images with boxes. If that works, your images are the problem: use PDF for diagrams and plots, and keep JPEG for photos.
3. Look for slow packages and content, such as large TikZ or pgfplots drawings. Compile them once to PDF and include the PDF instead.

“Missing $ inserted”

This is the most common beginner error. It means LaTeX found a maths-only character, usually an underscore or caret, in normal text. This line causes it:

Open the file config_prod.yaml and set the timeout.

Compiling it produced main.tex:3: Missing $ inserted, pointing at the underscore on line 3. Escape the special characters instead:

Open the file \texttt{config\_prod.yaml} and set the timeout to 50\%.

The characters that need a backslash in normal text are # $ % & _ { }; the tilde, caret and backslash need commands such as \textasciitilde, \textasciicircum and \textbackslash.

“Undefined control sequence”

A command is misspelled or its package isn’t loaded, for example using \includegraphics without \usepackage{graphicx}. Click the error in the log to jump to the line, then fix the spelling or add the package. Because Overleaf ships a full TeX Live distribution, you almost never need to install packages yourself.

Citations show as [?]

The key in \cite{...} doesn’t match an entry in your .bib file, or the .bib file isn’t named in \bibliography{...}. Check the spelling, then recompile; Overleaf runs BibTeX or Biber automatically.

Overleaf AI Features

Overleaf now has built-in AI tools that can explain and help fix compile errors, generate tables and equations, and suggest wording. Every plan has a daily AI allowance; the free plan has a basic allowance without the AI Assistant, and paid plans get more uses and the Assistant. Organisations can switch AI features off. As with any AI writing tool, check the generated LaTeX and never let it invent citations.

Overleaf Alternatives

For most people the choice is simple: use Overleaf when you collaborate or don’t want to install anything, and a local setup when you work offline or hit the free compile limit. Because both run LaTeX, you can move a project between them at any time. For more writing tools compared, see the best technical writing tools.

Conclusion

Overleaf is LaTeX without the setup: an online editor, a full TeX Live distribution and a live PDF preview, with real-time collaboration built in. The free plan is enough for papers, CVs and most reports; upgrade, or use your institution’s licence, when you need longer compiles, track changes, full history or Git. Start from a template or the structure above, keep sections in separate files, label everything you reference, and fix errors from the first one in the log.

FAQs