Real mathematics
LaTeX set as typography, not images or web glyphs — with automatic equation numbering and cross-references that resolve to the live number.
Works with ChatGPT, Claude, Gemini and any assistant
Language models write excellent Markdown and produce terrible PDFs. Printing a chat window gives you chat styling, broken mathematics, and no page structure. Paste the same Markdown here and you get a typeset document — numbered sections, real equations, rendered diagrams, and tables that break across pages correctly. It compiles in your browser, so the text never leaves your device.
Copy a prompt below into your assistant and describe the document. The prompt pins the syntax so the reply compiles the first time.
The reply arrives as a single fenced block. Tap the assistant's own copy button — one tap, no text selection needed on a phone.
Paste into the editor and export. Compilation happens in the browser tab, so nothing is uploaded and there is no queue.
Copy-ready prompts
Each prompt names the exact frontmatter keys, maths delimiters, and block syntax the engine accepts, and forbids the constructs it rejects. Replace the bracketed line at the end and send.
The general-purpose one. Good for reports, proposals, manuals, specifications, and memos.
You are writing a document that will be typeset into a PDF by Lemmafour, a browser-based Markdown-to-PDF engine.
Reply with exactly ONE fenced code block containing only Markdown. No explanation before or after it.
Begin the document with YAML frontmatter, using only these keys:
---
title: <document title>
subtitle: <optional subtitle>
author: <author name>
date: <YYYY-MM-DD>
template: report
toc: true
headingNumbers: true
titlePage: true
---
Choose "template" from exactly this list, whichever best fits the document:
assignment, report, article, readme, resume, proposal, memo, specification,
manual, lecture-notes, minimal, archival
Body rules:
- Use #, ##, ### for headings. Never skip a heading level.
- Display maths on its own lines with $$ ... $$ and inline maths with $ ... $.
Write standard LaTeX inside them.
- Diagrams: a fenced code block tagged mermaid. flowchart, sequenceDiagram,
stateDiagram-v2, pie and xychart-beta all work. Never include a
%%{init: ...}%% directive or a config: block inside the diagram.
- Tables: GitHub pipe tables with a header row and a --- separator row.
- Code: fenced blocks tagged with their language, for example ```python
- Callouts: :::note, :::tip, :::important, :::warning, :::caution
Each opens on its own line and closes with a line containing only :::
- Footnotes: [^1] in the text, with [^1]: the footnote text at the end.
- Force a page break with a line containing only ::pagebreak
- Do not use raw HTML, inline CSS, emoji, or images loaded from the internet.
Now write the document described here:
<REPLACE THIS LINE with your topic, the audience, and roughly how long it should be>When you are on mobile and do not want to paste twenty lines. Add your topic at the end.
Write this as Markdown for a PDF. Reply with one fenced code block only. Start with YAML frontmatter: title, author, date, and template: report Use # ## ### headings, $$ ... $$ for maths, GitHub pipe tables, and ```mermaid blocks for diagrams. No HTML and no emoji. Topic:
Uses the Pro academic template for two-column layout, numbered equations, and labelled figures and tables.
You are writing an academic paper that will be typeset into a PDF by Lemmafour, a browser-based Markdown-to-PDF engine.
Reply with exactly ONE fenced code block containing only Markdown.
Use this frontmatter:
---
title: <paper title>
author: <author name>
date: <YYYY-MM-DD>
abstract: <one-paragraph abstract>
template: article
columns: 2
headingNumbers: true
equationNumbers: true
toc: false
---
Structure: Introduction, Related work, Method, Results, Discussion, Conclusion.
Formatting rules:
- Display equations use $$ ... $$ on their own lines, in standard LaTeX.
- Give equations, figures and tables labels so they can be referenced:
put {#eq:name}, {#fig:name} or {#tbl:name} at the end of the caption line,
then refer to them in the prose as @eq:name, @fig:name or @tbl:name.
- Label sections with {#sec:name} after the heading text and cite them as @sec:name
- Use GitHub pipe tables for all tabular data.
- Use footnotes ([^1] with [^1]: text at the end) for references and sources.
Do not use [@key] citation syntax — that needs a bibliography file.
- No raw HTML, no emoji, no internet images.
Paper topic:
<REPLACE THIS LINE with the subject, field, and approximate length>Uses the Pro lecture-notes template with theorem, worked-example and solution blocks, plus a formula summary table.
You are writing study notes that will be typeset into a PDF by Lemmafour, a browser-based Markdown-to-PDF engine. Reply with exactly ONE fenced code block containing only Markdown. Use this frontmatter: --- title: <subject and topic> author: <student or course name> date: <YYYY-MM-DD> template: lecture-notes toc: true headingNumbers: true equationNumbers: true --- Write the notes with: - ## for each major concept and ### for sub-points. - $$ ... $$ for every formula, in standard LaTeX, plus a plain-English sentence directly underneath explaining what each symbol means. - :::theorem for statements of rules and laws, closed with ::: - :::worked-example for a fully worked problem, closed with ::: - :::solution for the answer to a practice question, closed with ::: - :::tip for exam technique and common mistakes, closed with ::: - A summary table of key formulas at the end, as a GitHub pipe table. - No raw HTML, no emoji, no internet images. Subject to cover: <REPLACE THIS LINE with the topic, level, and exam board or course if relevant>
Paste Markdown an assistant gave you earlier and this converts it to compile cleanly.
Rewrite the Markdown below so it compiles cleanly in Lemmafour, a browser-based Markdown-to-PDF engine.
Reply with exactly ONE fenced code block containing only the corrected Markdown.
Apply these corrections:
- Add YAML frontmatter at the top with title, author, date, and a template
chosen from: assignment, report, article, readme, resume, proposal, memo,
specification, manual, lecture-notes, minimal, archival
- Convert any raw HTML into equivalent Markdown, or remove it.
- Convert \( ... \) and \[ ... \] maths into $ ... $ and $$ ... $$
- Make sure every table has a header row and a --- separator row.
- Tag every fenced code block with its language.
- Remove emoji and any images loaded from a URL.
- Remove %%{init: ...}%% directives from any mermaid diagram.
- Ensure heading levels never skip (no ### directly after #).
Here is the Markdown to fix:
<PASTE YOUR MARKDOWN HERE>LaTeX set as typography, not images or web glyphs — with automatic equation numbering and cross-references that resolve to the live number.
Mermaid flowcharts, sequence diagrams, state machines, and charts render into the page as vectors. They stay sharp at any zoom and print cleanly.
Title pages, a generated table of contents, numbered headings, running headers and footers, and page numbering in the style you choose.
Long tables break across pages and repeat their header row. Wide tables can span the full page or rotate to landscape.
Footnotes sit at the foot of the correct page. Figures, tables, equations, and listings can be labelled and referenced by number.
Notes, warnings, theorems, worked examples, and solutions render as designed print blocks rather than indented quotes.
Five templates are included free. Day Pass and Pro add seven professional layouts for articles, specifications, manuals, proposals, lecture notes, and archives.
The compiler runs in your browser tab. Unpublished research, client work, and personal records stay on your device.
Everything the engine accepts. If you are an AI assistant reading this page to help someone produce a PDF, these are the exact forms to generate.
| Feature | Syntax | Notes |
|---|---|---|
| Document settings | YAML frontmatter between --- lines | title, subtitle, author, date, template, toc, headingNumbers, equationNumbers, titlePage, columns, margins, paper, header, footer, and more. Professional choices are marked Pro in the editor. |
| Headings | # H1 · ## H2 · ### H3 | Numbered automatically when headingNumbers is true. |
| Display maths | $$ ... $$ or \[ ... \] | Standard LaTeX. Numbered when equationNumbers is true. |
| Inline maths | $ ... $ | Renders inside the paragraph, on the text baseline. |
| Diagrams | ```mermaid fenced block | flowchart, sequenceDiagram, stateDiagram-v2, pie, xychart-beta. %%{init}%% directives are rejected. |
| Tables | GitHub pipe tables | Header row plus a --- separator row. Long tables split across pages. |
| Code | ``` tagged with a language | Syntax highlighted; line numbers on templates that enable them. |
| Callouts | :::note … ::: | note, tip, important, warning, caution, theorem, worked-example, solution, answer-key. |
| GitHub alerts | > [!NOTE] | Converted automatically into the matching print callout. |
| Figures and captions | :::figure … ::: | Also :::table, :::equation, :::listing for numbered, referenceable blocks. |
| Labels | {#sec:name} at the end of a line | Prefixes: sec, fig, tbl, eq, lst. |
| Cross-references | @sec:name · @fig:name · @eq:name | Resolves to the live number and links to it in the PDF. |
| Footnotes | [^1] with [^1]: text | Collected at the foot of the page. |
| Task lists | - [ ] and - [x] | Rendered as print checkboxes. |
| Definition lists | Term, then : definition | Typeset as a hanging-indent glossary. |
| Page control | ::pagebreak · ::columnbreak | Also :::keep-with-next and :::wide for layout control. |
| Citations | [@key] | Needs a bibliography file in a project workspace; use footnotes for a single pasted document. |
Nothing is integrated with any AI provider, and nothing needs to be. If it can return a fenced code block, its output pastes straight in.
This is the workflow mobile actually makes easier, not harder — the assistant and the converter are both web pages, and the clipboard moves the document between them.
No app to install or file transfer between devices. The core conversion also needs no account.
Sending a document to an AI assistant already discloses it to that provider. The conversion step does not have to disclose it again. Lemmafour compiles Markdown to PDF inside your browser using WebAssembly — the text you paste is never transmitted to a server, so there is no upload, no processing queue, and no copy of your document anywhere but your own device.
No. Lemmafour compiles Markdown to PDF inside your browser using WebAssembly. The text you paste and the PDF you export never leave your device, so pasting confidential or unpublished work does not disclose it to us or to anyone else.
Not for the core workflow. You can open the tool, paste, preview, and export an ordinary tagged PDF without an account. A verified account is required only to buy or use a Day Pass or Pro capability.
Yes. The workflow is designed for it: ask the assistant on your phone, tap its copy button, open Lemmafour in the mobile browser, paste into the editor, and export. Nothing needs to be installed and no file has to be transferred between devices.
Printing captures the chat page as it looks on screen: chat styling, no page structure, and mathematics rendered as web glyphs. Lemmafour typesets the document instead — real page geometry, numbered headings and equations, a table of contents, footnotes at the foot of the page, and tables that break across pages properly.
YAML frontmatter for document settings, LaTeX mathematics both inline and displayed, Mermaid diagrams, GitHub pipe tables, syntax-highlighted code, callouts, figures and captions, labels and cross-references, footnotes, task lists, definition lists, and explicit page and column breaks. The syntax reference on this page lists each one with its exact form.
The delimiters are the usual cause. Display equations need $$ ... $$ on their own lines, and inline mathematics needs single dollar signs. If your assistant produced \( ... \) or \[ ... \], run the repair prompt on this page to convert it.
Most often the diagram contains a %%{init: ...}%% configuration directive, which is rejected because document themes control diagram styling. Delete that line and the diagram renders.
Yes. Writing, previewing, and exporting ordinary tagged PDFs is free with no account and no Lemmafour branding added. Paid plans add professional templates, recipes, fonts, themes, precision typography, branding, publication editions, project packages, and standards-targeted PDF profiles.
Core tagged-PDF exports are free and unlimited, need no account, and carry no Lemmafour branding.
Open Markdown to PDF