Cloud LaTeX is a free online LaTeX environment run by the Japanese company Acaric. Its defining strength is that Japanese typesets with no configuration from the moment you sign in: unlike Overleaf, you do not switch engines or write a latexmkrc — you just type Japanese and compile, and a PDF comes out. The broad survey of online editors lives on “Try it online”; this page focuses on Cloud LaTeX itself — why Japanese works out of the box, how compilation on their servers works, and the practical workflows around Dropbox sync, the VS Code extension, and public share links.
Who runs it, and why
It is operated by Acaric Co., Ltd. (Tokyo), a company whose main business is career support for graduate students and researchers. Cloud LaTeX began as a prototype built by a chemistry master’s student at a national university who wanted to write LaTeX without setting up an environment; it won Acaric’s app-development contest, and the company invested to grow it. It launched in beta in 2014 and as an official product in 2016, has surpassed 50,000 cumulative registrations, and adds more than ten thousand new users a year. It is free, and you can start writing as soon as you register.
It is worth being precise about collaboration. Cloud LaTeX’s model is built around share (public) links and Dropbox sync rather than Overleaf-style live co-editing, where several cursors move over the same manuscript at once. So for many people writing simultaneously, Overleaf is a step ahead, while for turnkey Japanese, Cloud LaTeX leads. We compare it with Overleaf on a separate page.
Why Japanese works out of the box
Cloud LaTeX bills itself as “the first service to natively support Japanese LaTeX.” Where the international services of the same era (ShareLaTeX and WriteLaTeX, later Overleaf) targeted English and did not assume Japanese, Cloud LaTeX was built around pLaTeX from the start. Concretely, the server’s default engine is platex, and latexmk runs the platex → dvipdfmx pipeline for you. So you never choose an engine or write a latexmkrc: you write a Japanese body and compile. The first stumbling block of a Japanese setup simply isn’t there.
The document below is a minimal Japanese example that compiles as-is if you paste it into a fresh Cloud LaTeX project. It uses the jsarticle class with no special font setup and no engine directive.
\documentclass{jsarticle}
\begin{document}
こんにちは、\LaTeX！
日本語が初期設定のまま組めます。数式も書けます:
\[ \int_0^1 x^2 \, dx = \frac{1}{3} \]
\end{document}The default platex handles characters in the ASCII and JIS X 0208 ranges. To use Unicode characters outside that range — some emoji or variant glyphs, in filenames or text — switch the engine to uplatex. You do this by placing a .latexmkrc in the project with upLaTeX settings, which changes it per project (the mechanism is the same latexmk configuration as on Overleaf; see the latexmk page for details). Many of the ready-made templates ship with this configuration already in place.
The template library is another real advantage for Japanese users. More than 100 templates are provided — starting with “科研費 LaTeX” (the Grant-in-Aid and JSPS-fellowship application forms) and spanning journals and conference styles, poster presentations, résumés, and even novels and essay collections — and common Japanese .sty/.bst files such as ceo.sty, jecon.bst, and IEEJtran.bst are bundled in. Each Grant-in-Aid season, that year’s application templates are published. If your writing is mostly Japanese, Cloud LaTeX is an easy pick.
Compiling in the cloud
Compilation happens entirely on Acaric’s servers. Your browser uploads the source and shows the returned PDF in the right pane — there is no local TeX Live or fonts to install. The current environment is TeX Live 2025 frozen (the year’s final release, pinned), and the server invokes the latexmk command to build. Because it is pinned to the frozen release, the same project reproduces in the same environment whenever you open it.
Your edits are always autosaved — there is no explicit save, and you can stop and resume at any time. There is also file versioning and restoration: choosing “Restore” from the “⋯” menu in the file tree rolls a file back to an earlier version (retention is roughly 90 days, up to 100 versions). The editor is tuned for TeX, with syntax highlighting and autocompletion of LaTeX commands, and it supports SyncTeX, so you can jump between a place in the source and the matching spot in the PDF.
It helps to know the practical limits on the cloud side: the compile timeout is about 2 minutes, storage is 1 GB per account, you can have up to 999 projects, and 500 files per project (though staying well under 100 is recommended for responsiveness). You designate which .tex is the compile target within a project, and multi-file projects are supported. Figures and the like go in by drag-and-drop, and you can download the whole project as a ZIP.
Dropbox sync, VS Code, and public links
While it is cloud-first, there are paths to connect it to your own setup. One is Dropbox sync: “Sync with Dropbox” in the menu exports a project to Dropbox preserving its folder hierarchy, and the “Import” function on your My Page pulls a Dropbox folder back in. This lets you keep the cloud compile environment while also working in a local editor or keeping your own backups.
The other is the VS Code extension. Acaric released it as official open source in December 2020, distributed through the VS Code Marketplace and GitHub. It automatically syncs your local VS Code with the server-side project in both directions; on save, compilation runs on the server, and the finished PDF is downloaded locally. In other words, you write in familiar VS Code without installing TeX Live locally. Authentication is just a client ID and token (plus your email) issued on your My Page and entered into the extension. It even supports offline editing, syncing automatically when you come back online.
For sharing, a March 2024 update (v2.102.0) added public project links. The “Share” button at the top of a project issues a view-only URL, and anyone — even without a Cloud LaTeX account — can open the project through that link with read-only permission. In view mode, they can download both the PDF and the ZIP source. It suits showing work to a reviewer or seminar group, or serving as a place to hand out a document.
In short, Cloud LaTeX is the shortest route to “Japanese works from the start” and “nothing to set up,” and via Dropbox or VS Code you can have it both ways with a local setup. If you need serious simultaneous multi-author editing, reach for Overleaf; if you are ready to commit to a local toolchain, consider installing TeX Live or MiKTeX.