LTeX+ LS
LTeX+ LS is an open-source language server under MPL-2.0 that brings grammar and spelling checks into editors for markup documents: LaTeX, Markdown, Typst, AsciiDoc, Org, Quarto and ten more formats. It checks with LanguageTool in more than 20 languages, works offline, and ships with Java and LanguageTool included, so nothing else is needed. Its reference client is the LTeX+ extension for Visual Studio Code.
What does LTeX+ LS do?
LTeX+ LS "implements a language server according to the Language Server Protocol (LSP) and provides grammar and spelling errors in markup documents (LaTeX, Markdown, etc.)." A language server is a background program an editor talks to for checks and suggestions, so one install serves any editor that speaks the protocol. "The documents are checked with LanguageTool."
It handles 16 markup formats, including BibTeX, ConTeXt, git commit messages, LaTeX, Markdown, MDX, Typst, AsciiDoc, Org, Neorg, Quarto, reStructuredText, R Markdown, R Sweave and XHTML, and can optionally check comments in many programming languages. It "supports over 20 languages: English, French, German, Dutch, Chinese, Russian, etc.", offers one-click replacements, word completion for English and German, user dictionaries and mixed-language documents. It comes "with everything included, no need to install Java or LanguageTool", and does not upload anything, though it can use external LanguageTool servers if you prefer.
Key facts
- Licence: MPL-2.0, copyright Julian Valentin, Daniel Spitzer and the LTeX+ Development Community.
- A language server, so it works in any editor that speaks the Language Server Protocol; the reference client is the LTeX+ extension for Visual Studio Code.
- 16 markup formats, including LaTeX, Markdown, Typst, AsciiDoc, Org, Quarto, reStructuredText, R Markdown and BibTeX; optional checking of code comments.
- More than 20 languages, including English, French, German, Dutch, Chinese and Russian.
- Checking is done by LanguageTool, which ships bundled along with Java, so nothing else needs installing.
- Offline: it does not upload anything, and can optionally use external LanguageTool servers.
- One-click replacement suggestions, word completion for English and German, user dictionaries, and mixed-language documents.
- A command-line mode prints results without an editor. Latest tagged release when read: 18.7.0 on 2026-06-13; 256 stars on 2026-09-17.
What does it replace, and where does it fall short?
LTeX+ replaces Grammarly for writing in markup: a thesis in LaTeX, documentation in Markdown or AsciiDoc, notes in Org or Quarto, where a plain checker trips over the syntax. It understands the markup, checks the prose inside it, and runs offline in your own editor. It is the pick for LaTeX and Markdown authors on the open-source alternatives to Grammarly page.
Where it falls short: it is a language server, so you need an editor that supports one, and it does no AI rewriting. Its README states neither platforms nor limitations. It is a small project at 256 stars, continuing an earlier one that its author stopped maintaining. For general writing anywhere, Writing Tools or Harper.
How does LTeX+ LS run?
Start the server locally or on another machine and connect it to your editor, or pass file paths on the command line for results with no editor at all. Java and LanguageTool are bundled, so there is nothing else to install; the website carries the step-by-step instructions. There is no hosted or paid tier.
Who is LTeX+ LS for?
Anyone writing LaTeX, Markdown, Typst or AsciiDoc in an editor that supports language servers, who wants grammar checking that understands the markup and stays offline. Someone writing in a word processor should use LanguageTool's extension.
What limits does the README state?
None stated in the README, which also does not state which operating systems it supports.
Questions people ask
Is LTeX+ open source?
Yes. LTeX+ LS is under MPL-2.0, an OSI-approved licence. It bundles LanguageTool, which is LGPL-2.1, and a Java runtime, so the download includes everything needed to check documents without installing anything else on your machine.
Which file formats does LTeX+ check?
Sixteen markup formats, including LaTeX, Markdown, MDX, Typst, AsciiDoc, Org, Neorg, Quarto, reStructuredText, R Markdown, R Sweave, ConTeXt, BibTeX, XHTML and git commit messages. It can also check comments in many programming languages, which is off until you turn it on.
Does LTeX+ work offline?
Yes. The README says it does not upload anything to the internet, because LanguageTool and Java are bundled and run locally. If you prefer, it can be pointed at an external LanguageTool server instead.
Which editors support LTeX+?
Any editor that speaks the Language Server Protocol. The reference client is the LTeX+ extension for Visual Studio Code, and a command-line mode prints results with no editor at all.
How is LTeX+ related to LTeX?
The README says Julian Valentin developed LTeX LS until version 16.0.0, and that LTeX LS was a fork of an earlier language server project. LTeX+ continues that line with a wider format list; the original repository is archived.
Sources
- LTeX+ LS README and LICENSE.md (MPL-2.0): github.com/ltex-plus/ltex-ls-plus, read 2026-09-17.
Compared with the others
On the open-source alternatives to Grammarly page, LTeX+ LS is the pick for latex, markdown and typst. MPL-2.0 language server checking 16 markup formats in 20+ languages with LanguageTool bundled, offline, in any editor that speaks the protocol.
Also on that page: LanguageTool for grammar in more than 25 languages, Harper for fast english checking in your editor, Writing Tools for ai rewriting anywhere on screen.
More writing and grammar
An Apache-2.0 English grammar checker from Automattic that lints a document in milliseconds, uses a fraction of LanguageTool's memory by its own measure, runs privately in your editor or in the browser through WebAssembly.
An LGPL-2.1 proofreading engine for English, Spanish, French, German, Portuguese, Polish, Dutch and more than 20 other languages, which you can run as your own HTTP server with an API, or inside LibreOffice.
An MIT command-line prose linter that turns a team's writing guidelines into checks that run in an editor, in CI and beside code, offline, understanding Markdown, AsciiDoc and code comments rather than plain text.
A GPL-3.0 system-wide writing assistant for Windows, Linux and macOS that rewrites, proofreads or summarises selected text anywhere with one hotkey, using a local model through Ollama or a cloud model with your own key.
Added September 17, 2026. Every claim above comes from the project's README, LICENSE or model card, read on September 17, 2026, or from the GitHub API on the date shown in the panel. Found an error? Write to reveneau@licheo.com and it is fixed in the next weekly pass. Repository: github.com/ltex-plus/ltex-ls-plus.
Running one of these inside your own environment, with your own data and your own security rules, is the kind of work Reveneau does. Read how a forward deployed engagement works.