Static site generation with Flask and Pelican: a comprehensive comparison

An in-depth comparison of Flask-FlatPages and Pelican for static site generation, covering implementation approaches, performance considerations, and best practices.

Introduction

When building static websites with Python, developers often find themselves choosing between Flask with Flask-FlatPages and Pelican. This article explores both approaches, examining their strengths, limitations, and ideal use cases to help you make an informed decision for your next project.

Before diving into the comparison, you should have:

Basic understanding of Python web development
Familiarity with static site concepts
Experience with templating engines (particularly Jinja2)
Working knowledge of Markdown

Understanding static site generation

Static site generators create pre-rendered HTML pages rather than generating content on-demand. This approach offers several advantages, including improved performance, enhanced security, and simplified deployment. Both Flask-FlatPages and Pelican provide Python-based solutions for this task, though they approach it differently.

Flask with Flask-FlatPages

Flask-FlatPages extends Flask's capabilities to handle static content through Markdown files. This approach maintains Flask's flexibility while adding static site functionality.

Implementation approach

from flask import Flask, render_template
from flask_flatpages import FlatPages

app = Flask(__name__)
app.config['FLATPAGES_EXTENSION'] = '.md'
pages = FlatPages(app)

@app.route('/')
def index():
    posts = [p for p in pages if "date" in p.meta]
    sorted_posts = sorted(posts, reverse=True, key=lambda p: p.meta['date'])
    return render_template('index.html', posts=sorted_posts)

Note

Flask-FlatPages supports YAML frontmatter by default, making it compatible with many existing static site workflows.

Content organisation

Flask-FlatPages allows for flexible content organisation through Python's routing system. Content files can be structured in directories that mirror your URL patterns:

content/
├── posts/
│   ├── flask-tutorial.md
│   └── python-tips.md
├── pages/
│   ├── about.md
│   └── contact.md
└── projects/
    └── portfolio.md

Development workflow

The development experience with Flask-FlatPages remains similar to traditional Flask applications. You maintain access to Flask's extensive ecosystem while gaining static site capabilities.

Tip

Use Flask's development server with debug mode enabled during content creation to see changes in real-time:

if __name__ == '__main__':
    app.run(debug=True)

</div>

Pelican

Pelican is purpose-built for static site generation, offering a more opinionated and streamlined approach. It provides built-in support for common blog features and content management patterns.

Content processing

Pelican processes content through a well-defined generation pipeline:

from pelican import Pelican
from pelican.settings import read_settings

settings = read_settings('pelicanconf.py')
pelican = Pelican(settings)
pelican.run()

Theme development

Pelican's theming system builds on Jinja2 while providing specific context variables and helpers:

{% extends "base.html" %}

{% block content %}
<article>
    <h1>{{ article.title }}</h1>
    <div class="metadata">
        <time datetime="{{ article.date.isoformat() }}">
            {{ article.locale_date }}
        </time>
    </div>
    {{ article.content }}
</article>
{% endblock %}

Important

Pelican themes must follow a specific structure to access built-in features like pagination and category pages.

Performance and deployment

Build performance comparison

Both solutions offer good build performance, but their characteristics differ:

Flask-FlatPages:
- Generates pages on-demand during development
- Requires additional setup for production static generation
- Maintains Flask's memory efficiency
Pelican:
- Processes all content during the build phase
- Optimised for batch processing of content
- Includes built-in performance optimisations for large sites

Deployment options

Production deployment workflows vary between the two approaches:

Flask-FlatPages requires additional steps to generate a fully static site:

from flask_frozen import Freezer

freezer = Freezer(app)

if __name__ == '__main__':
    freezer.freeze()

Pelican provides built-in deployment capabilities:

pelican content -o output -s publishconf.py

Integration with modern tools

Flask-FlatPages with Alpine.js and Tailwind CSS

Flask-FlatPages works seamlessly with modern frontend tools. Here's how you can integrate Alpine.js and Tailwind CSS into your Flask static site:

<!-- In your base template -->
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>{{ page.title }}</title>
    <script defer src="https://cdn.jsdelivr.net/npm/alpinejs@3.x.x/dist/cdn.min.js"></script>
    <link href="https://cdn.jsdelivr.net/npm/tailwindcss@4.x.x/dist/tailwind.min.css" rel="stylesheet">
</head>
<body>
    <div x-data="{ darkMode: false }">
        <header x-bind:class="darkMode ? 'bg-gray-800 text-white' : 'bg-white text-gray-800'">
            <button @click="darkMode = !darkMode">Toggle theme</button>
        </header>
        <main>
            {% block content %}{% endblock %}
        </main>
    </div>
</body>
</html>

Pelican's plugin ecosystem

Pelican offers a rich plugin ecosystem that can extend its functionality:

# In pelicanconf.py
PLUGINS = [
    'sitemap',
    'seo',
    'related_posts',
    'optimize_images'
]

Making the choice: decision framework

Consider Flask with Flask-FlatPages when:

Your site requires dynamic features alongside static content
You need to maintain consistency with existing Flask applications
Custom build processes or integrations are required
You prefer working within a familiar Flask application structure

Choose Pelican when:

Building content-focused sites like blogs or documentation
You prefer a convention-over-configuration approach
Built-in features like RSS feeds and sitemap generation are priorities
Content organisation and taxonomies are central to your site

Caution

While both tools can handle large sites, carefully consider content volume and update frequency when choosing between them. Pelican's batch processing approach may be more suitable for sites with frequent content updates.

Containerisation considerations

Both solutions can benefit from Docker containerisation for consistent development and deployment environments:

# Flask-FlatPages Dockerfile example
FROM python:3.11-slim

WORKDIR /app

COPY requirements.txt .
RUN pip install -r requirements.txt

COPY . .

CMD ["python", "app.py"]

For Pelican, a similar approach works well:

# Pelican Dockerfile example
FROM python:3.11-slim

WORKDIR /app

COPY requirements.txt .
RUN pip install -r requirements.txt

COPY . .

CMD ["pelican", "content"]

Conclusion

Both Flask-FlatPages and Pelican offer robust solutions for static site generation in Python. Flask-FlatPages provides flexibility and integration with Flask's ecosystem, while Pelican offers a more specialised, feature-rich approach for content-focused sites. Your choice should align with your specific requirements, development workflow preferences, and maintenance considerations.

To continue exploring static site generation:

Experiment with both solutions using sample content
Review deployment strategies for your chosen platform
Explore the broader ecosystem of plugins and extensions
Consider contributing to either project's community