Build a PDF Toolkit with Python: Day 3: With FastHTML Web Interface

Level: Beginner

Projects in this week’s series:

This week, we progressively build a PDF toolkit with Python.

• Day 1: PDF Merger

• Day 2: PDF Splitter + Page Extractor

• Day 3: Web App PDF Toolkit (FastHTML) (Today)

View All Projects This Week

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Today’s Project

Welcome to the finale! We’ve built a PDF merger and a multi-function toolkit with splitting, extracting, rotating, and compressing. Today we’re wrapping everything in a modern web application using FastHTML — a new and fast way to build HTML apps with pure Python!

FastHTML lets you build web apps with just Python code — no separate HTML/CSS/JS files needed. Everything maps directly to HTML but feels natural in Python.

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Getting Started with FastHTML

What is FastHTML? FastHTML is a new Python web framework that lets you build full web applications using only Python. Unlike other frameworks, FastHTML maps directly 1:1 to HTML and HTTP, making it both powerful and intuitive.

FastHTML vs Streamlit?

Lets compare these two frameworks since they are quite similar:

FastHTML offers several advantages:

• Full control - You write actual HTML/HTTP, not a black box widget system

• Production-ready - Built on Starlette/ASGI, same foundation as FastAPI

• True web apps - Real routes, forms, and HTTP - not a data science dashboard

• Smaller & faster - Lightweight framework, minimal overhead

• No restrictions - Can build any web app (APIs, auth, databases, etc.)

• Learn real web dev - Teaches actual HTML/HTTP concepts

When to use Streamlit: Quick data dashboards, internal tools, ML demos

When to use FastHTML: Production web apps, user-facing sites, full-stack applications

Installation of fasthtml:

pip install python-fasthtml

Basic Example:

from fasthtml.common import *

app, rt = fast_app()

@rt('/')
def get(): 
    return Div(H1('Hello World!'), P('Built with FastHTML'))

serve()

That’s it! Run it with python main.py and visit localhost:5001 and you will see this:

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Deployment Options

FastHTML apps are standard ASGI applications, giving you many deployment options:

Easy Options (Beginner-friendly):

• Railway.app - Click to deploy, free tier available

• Render.com - Free tier, simple deployment

• PythonAnywhere - Python-focused hosting, easy setup

Production Options:

• DigitalOcean App Platform - Managed service, scales automatically

• AWS Lambda + API Gateway - Serverless, pay per use

• Fly.io - Edge deployment, fast globally

• Google Cloud Run - Containerized deployment

Since FastHTML uses ASGI (like FastAPI), any hosting that supports FastAPI will work perfectly with FastHTML. Most platforms offer one-click deployment or simple configuration files.

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Project Task

Now back to our project. The task today is to a FastHTML web app that:

• Uses FastHTML’s pythonic syntax for HTML

• Creates routes for each PDF operation

• Handles file uploads directly in Python

• Performs all operations from Days 1 & 2

• Provides download links for results

• Uses HTMX for interactivity (built into FastHTML)

• Runs as a single Python file

• Feels fast and responsive

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Setup

Install FastHTML and PyPDF2:

pip install python-fasthtml PyPDF2

Run the app:

python solution.py

Visit:

http://localhost:5001

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Expected Output

The page will have several pages. Here is one of the pages for splitting PDFs:

Once the user presses the “Split into Pages” button they instantly get the results:

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What You’ve Accomplished This Week

That’s for this week!

🎉 Congratulations!

We built a complete PDF toolkit and learned:

• Day 1: File merging and folder scanning

• Day 2: PDF manipulation (split, extract, rotate, compress)

• Day 3: Modern web apps with FastHTML

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View Code Evolution

And finally the code for our FastHTML app:

Compare today’s solution with earlier versions and see how we evolved from a simple script to a modern web app using FastHTML.