You do not need to install anything to try LaTeX. Open an online editor in a browser, make an account, paste in a dozen lines and press “Recompile” — five minutes covers all of it. And what runs the moment you press it is a complete TeX installation carrying thousands of packages. This page is about that first five minutes only: what is happening on the far side of the browser, how the first session actually unfolds, and the three things everyone runs into straight away — the compile timeout, the range of packages available, and where your file is really stored. Comparing the services, and deciding whether to stay in the cloud or move to your own machine, belong on another page.
What the browser is actually doing when you press Recompile
Almost nothing. The typesetting runs on a server. Your browser sends up a string of source; on the far side sits a machine with a whole TeX Live installation, where pdflatex or lualatex is executed, and the resulting PDF comes back and fills the right half of the screen. That is the entire mechanism. An online editor is therefore not a lightweight imitation of TeX: it is the same engine, the same packages, the same output as a local install. What you learn carries over to your own machine intact, and a source file that works locally will usually compile there without changes.
Which service you open matters less than you would think at this stage. Overleaf is the most widely used, Cloud LaTeX sets Japanese correctly with no configuration, and Papeeria has a free tier with unlimited public projects. There are others — CoCalc, which folds an editor into a scientific-computing workspace, plus TeXpage and Authorea — but whichever you pick, the experience is the same: type source, press a button, get a PDF. Open one and spend five minutes in it. Comparing them can wait.
% paste this in, press Recompile, and you have used LaTeX
\documentclass{article}
\begin{document}
Hello from the browser. Here is an equation:
\[ \int_0^1 x^2 \, dx = \frac{1}{3} \]
\end{document}How the first session actually goes
Do not build an elaborate setup from a blank page — that is the single most useful habit in the first half hour. Open a template or the minimal example above, replace one paragraph with your own words, compile, and save that working state. Then add headings, equations, figures, and references one at a time. The advantage is that when something breaks, the culprit is already known: undoing the last thing you added always fixes it, so there is no detective work. Start instead with ten \usepackage lines stacked up, and the first error tells you nothing about which of them caused it.
The first error is usually one of two. Misspell a command and you get ! Undefined control sequence.; type _ or ^ in ordinary text and you get ! Missing $ inserted. — the latter is TeX insisting that subscripts belong to maths, and it is fixed by writing \_ or by entering maths, as in $x_1$. Online editors show you these in a list where the PDF would be, but always fix the topmost error first. TeX errors cascade: the ones further down are usually aftershocks of the first, and they vanish along with it. If the PDF still looks stale afterwards, look for the menu entry equivalent to “Recompile from scratch,” which throws away the cached auxiliary files and rebuilds.
The first wall you hit: the compile timeout
A server cannot give one person’s manuscript unlimited time, so free tiers impose a compile timeout. According to Overleaf’s own documentation, as of 2026 the free plan allows 10 seconds and paid plans 240 seconds. A dozen practice lines will never come close, but a heavy TikZ drawing, dozens of high-resolution images, a pgfplots graph plotting tens of thousands of points, or a long thesis genuinely will. When it is exceeded, no PDF appears — you get a timeout notice instead.
The remedies are well established. First, shrink your images — dozens of 300 dpi submission-quality figures left at full size are the commonest cause of overrun. Next, skip image rendering with \documentclass[draft]{article} or the service’s own draft or fast mode. If the figures themselves are heavy, compile each TikZ picture once, write it out as a PDF, and pull it back in with \includegraphics from then on; the external library automates exactly this. If that is still not enough, split the document into per-chapter files and build only the chapter you are working on with \includeonly. And by the time you are hitting this wall in earnest, it is usually time to install TeX locally.
How far do the packages go
Nearly all of them. The major services carry a complete TeX Live, so anything on CTAN generally works the moment you write \usepackage. The familiar local frustration of a missing package essentially does not occur online. Three other things do catch people. First, packages that call external programs: minted launches Python’s Pygments for syntax highlighting, so it needs -shell-escape enabled, and whether and how you can do that varies by service. Second, your own fonts — an OTF or TTF has to be uploaded and loaded with fontspec, which of course means switching the compiler to XeLaTeX or LuaLaTeX. Third, the TeX Live vintage: if the service is running an older one, the newest features of the newest packages will not be there.
There is now a route that uses no server at all: compiling in the browser itself via WebAssembly, of which SwiftLaTeX is the best-known example. It ports pdfTeX and XeTeX to WebAssembly, runs them on your own machine, and fetches only the packages it needs from a CTAN mirror. With no server round trip, the notion of a timeout disappears, and your source never leaves the device. But its package coverage and track record do not yet match a full TeX Live, so for a first try the server-based services remain the quicker path.
Where the file you are writing actually lives
Not on your computer, but on the provider’s server. Obvious as that sounds, it is easy to lose sight of in the first five minutes, and it has three practical consequences. First, where to keep unpublished research or anything confidential becomes a question to settle against your institution’s rules, not a matter of convenience. Second, check early how you get the source out: downloading the PDF is universal, but whether you can extract the whole bundle — the .tex plus images — as a ZIP, over Git, or through Dropbox varies by service. A document begun as an experiment routinely turns into the real thing, and at that point you want an exit. Third, losing the account means losing the manuscript, so pull a copy down to your own disk at each milestone.
One more thing to settle within the first five minutes if you intend to write Japanese. Most services default to the pdfLaTeX compiler, which cannot set Japanese at all; type Japanese with no configuration and you get either an error or a PDF with the characters missing. Switch the compiler to LuaLaTeX in the menu and use ltjsarticle or jlreq, and it works. Some services, Cloud LaTeX among them, handle Japanese out of the box, which is a fair basis for choosing if Japanese is your main language. If you need the pLaTeX route common in Japanese journals, you will have to add a latexmkrc to the project that calls platex and then dvipdfmx — not a five-minute job; the Overleaf page walks through it. Either way, get one short Japanese sentence to compile before you start writing the body.
% first set the compiler to LuaLaTeX in the service menu
\documentclass{ltjsarticle}
\begin{document}
こんにちは、\LaTeX。数式も書けます: $e^{i\pi}+1=0$
\end{document}- If you already know your target venue, find its official template in the service’s gallery before writing anything — IEEE, ACM (the
acmartclass) and Springer Nature’s LNCS all have official ones there, and it is reliably faster than a blank page. If the venue gave you a.sty, just upload it beside your.tex. - For Japanese, get one short sentence to compile before starting the body; the default
pdfLaTeXcannot set it. - Confirm early that you can export the whole bundle —
.texand images, not just the PDF — via ZIP, Git, or Dropbox. - Fix errors from the top down. TeX errors cascade, and the ones lower in the list often vanish once the first is gone.
- Practice files will never approach the timeout, but once you start pasting in many images, suspect their resolution and dimensions first.