[Troubleshooting] Fixing Broken LaTeX Rendering in Jekyll Chirpy

Introduction

After migrating my algorithm posts to Jekyll Chirpy, I noticed a glaring issue. Complex mathematical formulas, which are essential for explaining time complexity like $O(N \log N)$ or recurrence relations, were displaying as raw text.

Instead of a beautifully rendered formula, I saw: $O(N \log N)$

This post documents why this happened and how I automated the fix for over 30 posts using a Python script.

The Problem

I use LaTeX syntax (wrapped in $) for mathematical expressions in my Markdown files. For example:

The time complexity is $O(N \log N)$.

I expected the theme to automatically render this using MathJax or KaTeX. However, it rendered literally as $O(N \log N)$.

Root Cause Analysis

The Jekyll Chirpy theme is optimized for performance. To avoid loading heavy JavaScript libraries like MathJax on every page, it only loads them on demand.

The trigger for loading MathJax is a specific variable in the Front Matter:

---
title: "My Post"
math: true  # <--- This was missing!
---

Since my migrated posts didn’t have this line, the theme assumed they were plain text posts and didn’t load the math rendering engine.

The Solution

The manual fix is simple: add math: true to the front matter of every post containing math. However, I have dozens of algorithm posts. Doing this manually is tedious and error-prone.

Automation with Python

I wrote a Python script to:

1. Scan all Markdown files in _posts/.
2. Detect if they contain LaTeX delimiters ($, \(, \[).
3. Check if math: true is missing.
4. Automatically insert math: true into the front matter.

Here is the script enable_math.py:

import glob
import re

def enable_math_in_files():
    # Find all markdown files in _posts
    files = glob.glob("_posts/*.md")
    
    for file_path in files:
        with open(file_path, 'r') as f:
            content = f.read()
            
        # Check if file contains math delimiters
        if not ("$" in content or "\\(" in content or "\\[" in content):
            continue
            
        # Check if math: true is already present
        if "math: true" in content:
            continue
            
        # Insert math: true before the second ---
        match = re.search(r'^---\s*$', content, re.MULTILINE) # First ---
        if match:
            end_match = re.search(r'^---\s*$', content[match.end():], re.MULTILINE) # Second ---
            if end_match:
                insert_pos = match.end() + end_match.start()
                
                new_content = content[:insert_pos] + "math: true\n" + content[insert_pos:]
                
                with open(file_path, 'w') as f:
                    f.write(new_content)
                print(f"Enabled math in {file_path}")

if __name__ == "__main__":
    enable_math_in_files()

Result

Running this script instantly fixed 13 posts that were missing the configuration, including:

• [BOJ] 11401. 이항 계수 3 (Heavy math content)
• [BOJ] 1920. 수 찾기 (Time complexity analysis)

Now, $O(N \log N)$ renders perfectly!

Conclusion

If your LaTeX formulas aren’t rendering in Jekyll Chirpy:

1. Check if math: true is in your Front Matter.
2. Don’t waste time editing files manually—script it!

This small automation saved me a lot of repetitive work and ensured no post was left behind.