Copies any selection containing KaTeX or MathJax as clean LaTeX (plain-text + HTML). Shortcut: ⌃/⌘+C or floating "Copy" button.
// ==UserScript==
// @name Copy-as-LaTeX for ChatGPT
// @namespace http://tampermonkey.net/
// @version 1.2.0
// @description Copies any selection containing KaTeX or MathJax as clean LaTeX (plain-text + HTML). Shortcut: ⌃/⌘+C or floating "Copy" button.
// @author yazanzaid00
// @match *://*.chatgpt.com/*
// @match *://chatgpt.com/*
// @match *://chat.openai.com/*
// @grant none
// @license MIT
// ==/UserScript==
function decodeHTMLEntities(text) {
const parser = new DOMParser();
return parser.parseFromString(text, 'text/html').documentElement.textContent;
}
function isEditable(node) {
if (!node) return false;
for (let n = node; n; n = n.parentNode) {
if (n.nodeType === Node.ELEMENT_NODE &&
n.matches('input, textarea, [contenteditable]')) {
return true;
}
}
return false;
}
const defaultCopyDelimiters = { inline: ['\\(', '\\)'], display: ['\\[', '\\]'] }; // alternative: inline: ['$', '$'], display: ['$$', '$$']
function katexReplaceWithTex(fragment, copyDelimiters = defaultCopyDelimiters) {
fragment.querySelectorAll('.katex-mathml + .katex-html')
.forEach(node => node.remove?.() || node.parentNode?.removeChild(node));
fragment.querySelectorAll('.katex-mathml').forEach(el => {
const ann = el.querySelector('annotation');
if (!ann) return;
el.replaceWith?.(ann) || el.parentNode?.replaceChild(ann, el);
ann.innerHTML = copyDelimiters.inline[0] + ann.innerHTML + copyDelimiters.inline[1];
});
fragment.querySelectorAll('.katex-display annotation').forEach(ann => {
const { inline, display } = copyDelimiters;
const body = ann.innerHTML.slice(inline[0].length, -inline[1].length);
ann.innerHTML = display[0] + body + display[1];
});
return fragment;
}
function closestKatex(node) {
const el = node instanceof Element ? node : node.parentElement;
return el?.closest('.katex') || null;
}
function mathjaxReplaceWithTex(fragment) {
// Remove preview & Assistive MathML duplicates
fragment.querySelectorAll('.MathJax_Preview, mjx-assistive-mathml')
.forEach(n => n.remove());
// Replace rendered MathJax blocks with their LaTeX annotation
fragment.querySelectorAll('annotation[encoding="application/x-tex"], annotation[encoding="LaTeX"]')
.forEach(ann => {
const tex = ann.textContent.trim();
const math = ann.closest('math');
if (!math) return;
// display="block" is set either on <math> or on its outer container
const isDisplay = math.getAttribute('display') === 'block' ||
ann.closest('mjx-container')?.getAttribute('display') === 'block';
const node = document.createTextNode(
(isDisplay ? defaultCopyDelimiters.display[0] : defaultCopyDelimiters.inline[0]) + tex + (isDisplay ? defaultCopyDelimiters.display[1] : defaultCopyDelimiters.inline[1])
);
math.replaceWith(node);
});
// Remove leftover rendered output
fragment.querySelectorAll('mjx-container, .MathJax').forEach(el => el.remove());
return fragment;
}
function replaceMathWithTex(fragment) {
katexReplaceWithTex(fragment);
mathjaxReplaceWithTex(fragment);
return fragment;
}
function getTextContentWithReplacements(node) {
let text = '';
if (node && node.childNodes) {
node.childNodes.forEach(child => {
let replaced = false;
if (child.nodeType === Node.TEXT_NODE) text += child.textContent;
if (child.nodeType === Node.ELEMENT_NODE) {
const nodeName = child.nodeName.toLowerCase();
if (nodeName === 'span' &&
child.getElementsByTagName('annotation').length > 0) {
replaced = true;
text += defaultCopyDelimiters.inline[0] + child.getElementsByTagName('annotation')[0].textContent + defaultCopyDelimiters.inline[1];
}
}
if (!replaced &&
child.nodeType === Node.ELEMENT_NODE &&
!['script', 'math', 'img'].includes(child.nodeName.toLowerCase())) {
text += getTextContentWithReplacements(child);
}
});
}
return text.replace(/\n+/g, '\n').trim();
}
function onCopy(event) {
/* Skip everything when the focus is in an editable control */
if (isEditable(event.target || document.activeElement)) return;
const sel = window.getSelection();
if (sel.isCollapsed || !event.clipboardData) return;
const range = sel.getRangeAt(0);
// Expand selection to whole KaTeX block
const sK = closestKatex(range.startContainer);
if (sK) range.setStartBefore(sK);
const eK = closestKatex(range.endContainer);
if (eK) range.setEndAfter(eK);
const frag = range.cloneContents();
if (!frag.querySelector('.katex-mathml') &&
!frag.querySelector('annotation[encoding="application/x-tex"], annotation[encoding="LaTeX"]')) {
return;
}
/* HTML clipboard data – remove hidden math markup to avoid duplicates */
const htmlClone = frag.cloneNode(true);
htmlClone.querySelectorAll('.katex-mathml, .MathJax_MathML, mjx-assistive-mathml')
.forEach(el => el.remove());
htmlClone.querySelectorAll('.MathJax_Preview, script[type*="math/tex"]')
.forEach(el => el.remove());
const tmp = document.createElement('div');
tmp.appendChild(htmlClone);
event.clipboardData.setData('text/html', tmp.innerHTML);
/* Plain-text clipboard data – KaTeX + MathJax → TeX */
const plain = decodeHTMLEntities(replaceMathWithTex(frag).textContent)
.replace(/\u00A0/g, ' ');
event.clipboardData.setData('text/plain', plain);
event.preventDefault();
event.stopImmediatePropagation();
}
(function () {
'use strict';
if (!window.__LaTeXCopierInstalled) {
// light DOM first
document.addEventListener('copy', onCopy, true);
// monkey-patch attachShadow so future roots inherit the listener
const orig = Element.prototype.attachShadow;
Element.prototype.attachShadow = function (init = {}) {
const root = orig.call(this, { ...init, mode: 'open' });
root.addEventListener('copy', onCopy, true);
return root;
};
// hook all *existing* open shadow roots (rare on ChatGPT but safe)
document.querySelectorAll('*').forEach(el => {
if (el.shadowRoot) el.shadowRoot.addEventListener('copy', onCopy, true);
});
window.__LaTeXCopierInstalled = true;
}
if (!document.getElementById('__latexCopyStyle')) {
const css = `
:root{--latex-bg:var(--background-secondary,#fff);--latex-fg:var(--text-primary,#000);--latex-hover:rgba(0,0,0,.05)}
html.dark{--latex-bg:var(--background-secondary,#2c2c2e);--latex-fg:var(--text-primary,#eee);--latex-hover:rgba(255,255,255,.10)}
.latex-copy-btn{all:unset;position:absolute;z-index:2147483647;display:none;visibility:visible;padding:4px 10px;border-radius:8px;cursor:pointer;background:var(--latex-bg);color:var(--latex-fg);backdrop-filter:blur(8px);border:1px solid rgba(0,0,0,.14);box-shadow:0 1px 3px rgba(0,0,0,.08);transition:background .15s}
.latex-copy-btn:hover{background:var(--latex-hover)}`;
const style = Object.assign(document.createElement('style'), { id: '__latexCopyStyle', textContent: css });
document.head.appendChild(style);
}
const button = Object.assign(document.createElement('button'), {
textContent: 'Copy', className: 'latex-copy-btn'
});
document.body.appendChild(button);
button.addEventListener('click', () => {
const sel = window.getSelection();
if (sel) copySelection(sel);
button.style.display = 'none';
});
let last = '';
document.addEventListener('mouseup', e => {
const s = window.getSelection().toString().trim();
/* Do NOT show the button if the mouse-up happened in an editable area */
if (s && s !== last && !isEditable(e.target)) {
button.style.left = `${e.pageX + 5}px`;
button.style.top = `${e.pageY + 5}px`;
button.style.display = 'block';
last = s;
} else {
button.style.display = 'none';
last = '';
}
});
function copySelection(selection) {
const range = selection.getRangeAt(0);
const sK = closestKatex(range.startContainer);
if (sK) range.setStartBefore(sK);
const eK = closestKatex(range.endContainer);
if (eK) range.setEndAfter(eK);
const frag = range.cloneContents();
let text;
if (frag.querySelector('.katex-mathml') ||
frag.querySelector('annotation[encoding="application/x-tex"], annotation[encoding="LaTeX"]')) {
text = replaceMathWithTex(frag).textContent;
} else {
text = getTextContentWithReplacements(frag);
}
text = text.replace(/\\bm\{([^}]+)\}/g, '\\mathbf{$1}')
.replace(/\\bigg\{\\\|\}/g, '\\Bigl|')
.replace(/\\big\{\\\|\}/g, '\\big|')
.replace(/\u00A0/g, ' ');
navigator.clipboard.writeText(decodeHTMLEntities(text));
}
document.addEventListener('keydown', e => {
if (!(e.ctrlKey || e.metaKey) || e.key.toLowerCase() !== 'c') return;
const sel = window.getSelection();
if (!sel || sel.isCollapsed || isEditable(sel.anchorNode)) return;
/* Intercept only when the fragment actually contains math */
const frag = sel.getRangeAt(0).cloneContents();
const hasMath = frag.querySelector('.katex-mathml') ||
frag.querySelector('annotation[encoding="application/x-tex"], annotation[encoding="LaTeX"]');
if (!hasMath) return; // plain text → let the browser handle it
e.preventDefault(); // math present → use custom copier
copySelection(sel);
}, true);
})();