querno Download
A local LaTeX editor. A simpler way to write.

A line of thought.A page of possibility.

thought.texLaTeX
\documentclass{article} \usepackage{amsmath}   \begin{document} \[ e^{i\pi} + 1 = 0 \] \end{document}
Saved on your computerUTF-8
Click to typeset
thought.pdfPreview
eiπ+1=0

Five constants. One beautiful identity.

Beautifully typeset1 / 1
01 The source
02 The page

Write the source. See the page take shape.
Querno brings them together, right on your computer.

Download for macOSHow it works
  • No account
  • No TeX installation
  • Your files stay yours
The Querno editor: a project sidebar, LaTeX source in the middle, and the typeset PDF with a plotted figure on the right.
Figure 1: A paper in progress. The PDF updates a moment after you stop typing.

Abstract

Querno is for people who would rather write LaTeX than maintain a TeX installation. It runs locally, typesets with a bundled engine, and shows the PDF next to the source while you work. Nothing is uploaded, and nothing needs an account. This page describes what it does, what it stores, and where its limits are.

1Type, pause, and it is typeset

Querno saves as you type and rebuilds the PDF when you stop. If a build fails, the last good PDF stays in place and the error points to the line that caused it.

main.tex
Up to date

A Short Note on Primes

Euclid of Alexandria

1Introduction

Every integer n > 1 has a prime factor.

Theorem 1 (Euclid). There are infinitely many primes.

N = p1p2 ⋯ pk + 1 (1)

Hence N has a prime factor not in the list.

1
Showing last successful PDF

2Built for real documents

Multi-file projects, bibliographies, figures, and the tools to keep track of them as a document grows.

1 error 2 warnings
!
This expression needs math mode Wrap inline math in $…$. Underscores and carets need math mode too.
results.tex:28
?
Citation “lamport1994” is undefined Add the entry to a .bib file, or check the key.
main.tex:41

Errors in plain language

Common TeX errors are explained in plain words and linked to the file and line. The full log is one click away.

27\section{Experiment} 28Figure~\ref{fig:loss} compares 29the bound with the measured

2Experiment

Figure 1 compares the bound with the measured error on a quadratic with condition number 20.

Source and PDF, linked both ways

“Show in PDF” scrolls to the line under your cursor. Double-click the PDF to jump back to the source that produced it.

  1. Successful build2 min ago · 6 files
  2. Sent to advisorYesterday · named
  3. Successful buildMon 14:02 · 5 files

Version history

A snapshot after every successful build, plus named versions whenever you like. Restoring saves the current state first.

  • chapters
  • introduction.tex
  • results.tex
  • figures
  • loss.png
  • main.texmain
  • references.bib

Multi-file projects

Folders, \input, images, class and style files. Renaming a file updates the references to it.

book Introductory Lectures on Convex Optimization Yurii Nesterov · 2004
nesterov2004 Insert citation +

Citations from your .bib

Browse entries in the sidebar and insert them in one click. Keys autocomplete inside \cite{}.

Articleℒ(θ) = ½∑(y − f)²
NotesDefinition 1.1
ReportContents
Alex Morgan
Experience
Street · CityDear Recipient,
Untitled

Six templates that compile on the first try

Article, notes, report, résumé, letter, and blank. Or import an existing project from a ZIP.

Light, dark, or system

The interface follows your choice. The PDF keeps the document’s own colors.

3Everything is stored on your disk

  1. No account, no sign-in, no analytics. Querno is a small local service. It listens only on your own machine and rejects requests from other sites.
  2. Projects are ordinary files. Sources, PDFs, and version history live in ~/.querno. Back up that folder and you have backed up everything.
  3. Leave whenever you like. Export any project as a plain ZIP of .tex, .bib, and image files that any LaTeX setup can build.
  4. The network is used for one thing. The first build of a document downloads the TeX packages it uses.1 Fonts and app assets are served locally.
~/.querno 
projects/
  3f2c…/
    project.json      # sources + metadata
    history/          # version snapshots
    outputs/          # PDFs + SyncTeX maps
    latest.json       # last good PDF
    build.json        # last build + log
  9a71…/
  c04e…/

4Tectonic is included. Your TeX distribution works too.

Bundled · default 0.17.0

Tectonic

Based on XeTeX. Downloads packages on demand, runs BibTeX, and repeats passes until cross-references settle. The binary is pinned and verified by SHA-256.

Uses your installation

pdfLaTeX, XeLaTeX, LuaLaTeX

Selectable per project when they are on your PATH. Querno runs the extra passes and calls BibTeX or Biber when the document asks for them.

Shell escape is always disabled, so packages that run external programs, such as some minted setups, need adjusting.

5Specifications

Table 1: What Querno runs on and what it keeps.
Platform macOS 13.5 or later on Apple Silicon.
Requirements No separate Node, Homebrew, or TeX installation required.
Typesetting Tectonic 0.17.0, bundled. pdfLaTeX, XeLaTeX, and LuaLaTeX when installed.
Bibliographies BibTeX, bundled. Biber with a local installation.
Storage ~/.querno: JSON manifests, PDFs, and snapshots.
History The 30 most recent automatic snapshots and every named version.
Limits 300 files per project, 20 MB per file, 3-minute build timeout.
Network TeX package downloads on a document’s first build. Nothing else.

6Questions

Do I need to install LaTeX first?

No. The portable app includes Tectonic, which fetches the packages each document needs and caches them. If you already have TeX Live or MacTeX, you can switch a project to pdfLaTeX, XeLaTeX, or LuaLaTeX.

Can I bring in an existing project?

Yes. Import a ZIP of your sources, including subfolders, images, .bib, .cls, and .sty files, then choose the main document in project settings.

Does it work without an internet connection?

Once a document has been built, yes. The first build downloads the TeX packages that document uses; after that they come from Tectonic’s local cache.

Is my writing uploaded anywhere?

No. The editor talks to a service on your own machine, bound to localhost. There are no accounts, analytics, or remote fonts.

What about Windows and Linux?

The current release is for Mac with Apple Silicon. Windows and Linux downloads are not available yet.

Why does macOS warn me when I open it?

The Mac app is ad-hoc signed and is not yet notarized. Use Finder’s Open command, or allow it under System Settings → Privacy & Security.

Get Querno

Mac app for Apple Silicon

macOS 13.5 or later. Includes its own runtime and typesetter.

Download for macOS
  1. Open the ZIP archive.
  2. Drag Querno.app into Applications.
  3. Open Querno from Applications or Spotlight.

Verify your download

Save the SHA-256 checksum beside the ZIP to verify your download.

Choose the Mac ZIP and matching checksum file from the latest release on GitHub.