Replaces specified fonts with alternatives across all page elements
Version au
// ==UserScript==
// @name Font Replacer
// @namespace https://openuserjs.org/users/pfzim
// @version 0.2
// @description Replaces specified fonts with alternatives across all page elements
// @author pfzim
// @copyright 2025, pfzim (https://openuserjs.org/users/pfzim)
// @license GPL-3.0-or-later
// @match *://*/*
// @grant none
// ==/UserScript==
(function ()
{
'use strict';
// Font replacement settings (format: { "target font": "replacement", ... })
const fontReplacements = {
"Helvetica": "Verdana",
"Kaspersky Sans": "Verdana",
"Verdana Neue": "Verdana",
"GitLab Sans": "Verdana",
"Segoe UI": "Arial",
"Inter": "Arial",
"Georgia": "Times New Roman",
"Roboto Mono": "Courier New",
"Roboto": "Verdana",
"Metropolis": "Verdana",
"Open Sans": "Verdana",
"Manrope": "Verdana",
"GitLab Mono": "Courier New"
//"Inter": "Arial"
// Add your custom replacements here
};
function parseAndReplaceFonts(fontFamilyString, replacements)
{
if(!fontFamilyString) return '';
const withoutComments = fontFamilyString.replace(/\/\*.*?\*\//g, '');
const fontList = [];
let currentFont = '';
let inQuotes = false;
let quoteChar = null;
let inParentheses = false;
let escapeNext = false;
for(let i = 0; i < withoutComments.length; i++)
{
const char = withoutComments[i];
if(escapeNext)
{
currentFont += char;
escapeNext = false;
continue;
}
if(char === '\\')
{
escapeNext = true;
currentFont += char;
continue;
}
if((char === '"' || char === "'") && !inParentheses)
{
if(!inQuotes)
{
inQuotes = true;
quoteChar = char;
} else if(char === quoteChar)
{
inQuotes = false;
quoteChar = null;
}
currentFont += char;
} else if(char === '(' && !inQuotes)
{
inParentheses = true;
currentFont += char;
} else if(char === ')' && !inQuotes)
{
inParentheses = false;
currentFont += char;
} else if(char === ',' && !inQuotes && !inParentheses)
{
if(currentFont)
fontList.push(processFont(currentFont, replacements));
currentFont = '';
} else
{
currentFont += char;
}
}
if(currentFont)
fontList.push(processFont(currentFont, replacements));
return fontList.join(', ');
}
function processFont(font, replacements)
{
let unquotedFont = font;
font = font.trim();
if(font.startsWith('"') && font.endsWith('"'))
{
unquotedFont = font.slice(1, -1).replace(/\\"/g, '"');
}
else if(font.startsWith("'") && font.endsWith("'"))
{
unquotedFont = font.slice(1, -1).replace(/\\'/g, "'");
}
const lowerFont = unquotedFont.toLowerCase();
for(const [original, replacement] of Object.entries(replacements))
{
if(lowerFont === original.toLowerCase())
{
return replacement;
}
}
return unquotedFont;
}
// // Function to replace fonts in a string
// function replaceFonts(fontFamily)
// {
// let newFontFamily = fontFamily;
// for(const [oldFont, newFont] of Object.entries(fontReplacements))
// {
// newFontFamily = newFontFamily.replace(
// new RegExp(`\\b${oldFont}\\b`, 'gi'),
// newFont
// );
// // Alternative matching approach (commented out):
// // if(newFontFamily.toLowerCase().includes(oldFont.toLowerCase()))
// // {
// // return newFont;
// // }
// }
// return newFontFamily;
// }
// Main element processing function
function processElement(element)
{
const computedStyle = window.getComputedStyle(element);
const originalFont = computedStyle.fontFamily;
if(!originalFont) return;
//const newFont = replaceFonts(originalFont);
const newFont = parseAndReplaceFonts(originalFont, fontReplacements)
if(newFont.toLowerCase() !== originalFont.toLowerCase())
{
element.style.fontFamily = newFont;
// Debug logging (commented out):
// console.log('Old font: ' + originalFont + '\nNew font: ' + newFont);
}
}
// Recursive function to check all elements
function checkAllElements(node)
{
processElement(node);
for(let i = 0; i < node.children.length; i++)
{
checkAllElements(node.children[i]);
}
}
// Process the entire page
checkAllElements(document.body);
// Monitor dynamically added elements
const observer = new MutationObserver(mutations =>
{
mutations.forEach(mutation =>
{
mutation.addedNodes.forEach(node =>
{
if(node.nodeType === 1) // Node.ELEMENT_NODE
{
checkAllElements(node);
}
});
});
});
observer.observe(document.body, {
childList: true,
subtree: true
});
// Optional: Add @font-face style to force font replacement (commented out)
// const style = document.createElement('style');
// style.textContent = `
// * {
// font-family: ${Object.values(fontReplacements).join(', ')} !important;
// }
// `;
// document.head.appendChild(style);
})();