Introduction to Gradio: How to Build Interactive Apps

Machine learning projects often start with a breakthrough – a model that finally performs well after hours of experimentation. But then comes the hard part: sharing it. How do you get feedback from others? How do you let non-technical stakeholders test it? How do you turn your Python code into something interactive?

That’s exactly where Gradio comes in. As an open-source Python library. Gradio helps developers and data scientists build simple interfaces for their models with minimal effort. Whether you need an image classifier, a website chatbot, a speech-to-text model, or even a multi-step data pipeline, Gradio will turn your Python functions into interactive demos that run in the browser. As a plus - no frontend experience needed.

What is Gradio?

Traditionally, turning a model into a web app requires a lot of glue code. You might spin up a Flask or FastAPI server, write HTML and JavaScript, host it somewhere, and hope it doesn’t break. This is a huge hurdle — particularly for solo developers or researchers who sometimes just need top test or/and share a model quickly.

Gradio solves this by abstracting away everything except the core logic. You just need to write your model as a function, define the inputs and outputs (like text, image, slider), allowing Gradio to automatically build a UI around it. You can launch the app locally, embed it into a Jupyter notebook, or share it via a public link. All from Python.

Gradio will best suit the following use cases:

• Testing model behavior interactively;
• Sharing demos with stakeholders or collaborators;
• Getting user feedback before deployment;
• Hosting portfolio projects;
• Participating in hackathons or competitions.

How Gradio Works (In 5 Lines)

Here’s what it looks like to build a simple sentiment analysis demo:

import gradio as gr

def predict_sentiment(text):
    return "Positive" if "good" in text.lower() else "Negative"

gr.Interface(fn=predict_sentiment, inputs="text", outputs="text").launch()

This will spin up a browser window with a textbox input and a result display. That’s it.

You can customize it further with image inputs, sliders, dropdowns, webcam access, code input, file uploads, and even custom components. Gradio supports stateful interactions too — useful for chatbots or step-based logic.

Key Gradio features

Gradio is popular because it makes things simple without being limiting. Here are some of its standout features:

• Fast UI generation: Build a working UI in minutes with just Python.
• Multi-modal support – Text, images, audio, video, code, and more.
• Live sharing – Add share=True to get a public URL instantly.
• Built-in hosting with Hugging Face Spaces – Deploy without any DevOps setup.
• Interactive examples – Let users test with predefined inputs.
• Custom themes and layouts – Adjust layout with Blocks and CSS.
• State management – Maintain conversation history or session variables.
• Open source – Free to use under Apache 2.0 license.

Pricing

Gradio itself is completely free and open-source.

You can use it locally, in your own cloud setup, or inside Jupyter notebooks at no cost. If you want to deploy your app to the web, the easiest option is using Hugging Face Spaces, which offers hosting and collaboration tools.

Hugging Face Spaces Pricing

• Free Tier – Community GPU/CPU options, ideal for personal or public demos
• Pro Tier – Paid access to private Spaces, better compute, and priority builds
• Enterprise – Managed infrastructure, team access, and security features

You only pay if you're using compute from Hugging Face. If you host it elsewhere, it’s free.

Gradio vs UI Bakery

While Gradio is ideal for quickly turning Python functions into interactive ML demos, it wont suit projects requiring full-scale internal tools or production-ready apps.  

UI Bakery is a low-code development platform designed for complex web apps, covering the front-end part with its drag-and-drop UI, database and API integrations, authentication, and role-based access control. In contrast to Gradio, which is Python-centric, UI Bakery supports broader use cases. Most common are building admin panels, dashboards, or CRUD apps that connect to real-time data sources.

Wrapping up

Gradio is one of the fastest and easiest ways to go from “model in a notebook” to “interactive web app.” Removing the friction of building UIs, Gradio also handles the boilerplate, and lets you focus on the logic.

Gradio will be an ideal choice for data scientists, ML engineers, or researchers who want to showcase their work without touching HTML or JS. UI Bakery will better suit complex web apps that require more features yet minimum coding experience.