How to Avoid JavaScript for Infinite Scrolling Using HTMX

Infinite scrolling is a popular UI pattern that allows users to scroll through a large set of data without having to click through pages. Traditionally, implementing infinite scrolling involves JavaScript to detect when the user reaches the bottom of the page and then loading more data. With HTMX, you can avoid writing custom JavaScript while achieving the same functionality using server-side rendering. In this tutorial, we’ll walk through how to implement infinite scrolling with HTMX, keeping your app fast and lightweight. Step 1: Set Up the Flask App Start by creating a simple Flask app that serves the main page and provides an endpoint to load more items as the user scrolls. First, install Flask if you don’t already have it: pip install flask Create a basic Flask app in app.py: from flask import Flask, render_template, jsonify app = Flask(name) # Sample data for infinite scrolling ITEMS = [f"Item {i}" for i in range(1, 101)] @app.route("/") def index(): return render_template("index.html") @app.route("/load-items/") def load_items(start): # Load a slice of the items based on the 'start' index end = start + 10 items_to_load = ITEMS[start:end] return render_template("partials/items.html", items=items_to_load) if name == "main": app.run(debug=True) Step 2: Create the HTML Templates Create templates/index.html, which will display the initial list of items and set up HTMX to load more content as the user scrolls. HTMX Infinite Scrolling Infinite Scrolling with HTMX Loading items... Scroll down to load more items... Create templates/partials/items.html: {% for item in items %} {{ item }} {% endfor %} Step 3: Add the Infinite Scroll Trigger The magic of infinite scrolling with HTMX happens in the hx-trigger="revealed" attribute. This triggers the request to load more items when the element becomes visible in the viewport (i.e., when the user scrolls to the bottom). HTMX listens for the revealed event, which fires when the div containing the hx-get attribute is scrolled into view. This makes it possible to load more data automatically as the user scrolls down the page. Step 4: Run the App and Test Now, run the Flask app: python app.py Visit http://localhost:5000/ in your browser. When you scroll down, new items will automatically load as you reach the bottom of the page. This is accomplished with HTMX without needing any custom JavaScript! ✅ Pros:

May 3, 2025 - 23:53

How to Avoid JavaScript for Infinite Scrolling Using HTMX

Infinite scrolling is a popular UI pattern that allows users to scroll through a large set of data without having to click through pages. Traditionally, implementing infinite scrolling involves JavaScript to detect when the user reaches the bottom of the page and then loading more data. With HTMX, you can avoid writing custom JavaScript while achieving the same functionality using server-side rendering.

In this tutorial, we’ll walk through how to implement infinite scrolling with HTMX, keeping your app fast and lightweight.

Step 1: Set Up the Flask App

Start by creating a simple Flask app that serves the main page and provides an endpoint to load more items as the user scrolls.

First, install Flask if you don’t already have it:

pip install flask

Create a basic Flask app in app.py:

from flask import Flask, render_template, jsonify

app = Flask(__name__)

# Sample data for infinite scrolling
ITEMS = [f"Item {i}" for i in range(1, 101)]

@app.route("/")
def index():
    return render_template("index.html")

@app.route("/load-items/")
def load_items(start):
    # Load a slice of the items based on the 'start' index
    end = start + 10
    items_to_load = ITEMS[start:end]
    return render_template("partials/items.html", items=items_to_load)

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

Step 2: Create the HTML Templates

Create templates/index.html, which will display the initial list of items and set up HTMX to load more content as the user scrolls.




  
  
  HTMX Infinite Scrolling
  


  Infinite Scrolling with HTMX

  
    Loading items...
  

  
    Scroll down to load more items...

Create templates/partials/items.html:

{% for item in items %}
  {{ item }}
{% endfor %}

Step 3: Add the Infinite Scroll Trigger

The magic of infinite scrolling with HTMX happens in the hx-trigger="revealed" attribute. This triggers the request to load more items when the element becomes visible in the viewport (i.e., when the user scrolls to the bottom).

HTMX listens for the revealed event, which fires when the div containing the hx-get attribute is scrolled into view. This makes it possible to load more data automatically as the user scrolls down the page.

Step 4: Run the App and Test

Now, run the Flask app:

python app.py

Visit http://localhost:5000/ in your browser. When you scroll down, new items will automatically load as you reach the bottom of the page. This is accomplished with HTMX without needing any custom JavaScript!

✅ Pros: