Overview
Streamlit is a Python framework for building interactive web apps from plain scripts. You write normal Python and call simple functions like st.slider or st.write, and Streamlit renders the widgets and output as a web page. There is no separate HTML, CSS, or JavaScript to manage.
It is aimed at data scientists, ML engineers, and Python developers who want to share dashboards, reports, or models without building a frontend. As you edit your script, the app updates so you can prototype and gather feedback quickly.
As a data app builder, Streamlit fits the gap between a notebook and a full web stack. You keep your work in one Python file, and you can deploy and share it through the free Streamlit Community Cloud.
What it does
- Build interactive apps in pure Python, with no frontend code required
- Input widgets such as sliders, plus dataframes, charts, and layout helpers
- Live editing: the app updates as you change and save your script
- Multi-page apps for organizing larger projects
- Extra functionality through community-built Streamlit Components
- Free deployment and sharing via Streamlit Community Cloud
Getting started
Install Streamlit with pip, confirm it works with the built-in demo, then write and run your first app.
Install and verify
Install Streamlit from PyPI, then run the bundled Hello app to confirm your setup. It should open in your browser.
pip install streamlit
streamlit helloWrite a minimal app
Create a file named streamlit_app.py with a slider and some output.
import streamlit as st
x = st.slider("Select a value")
st.write(x, "squared is", x * x)Run your app
Start the app from your terminal; it opens in the browser and reloads as you edit the script.
streamlit run streamlit_app.pyCommands and code are distilled from the project's own documentation — always check the official repo for the latest.
When to use it
- Build an interactive dashboard to explore a dataset and share it with your team
- Wrap a machine learning model in a simple UI so others can try it with their own inputs
- Create an LLM or chatbot app where users type prompts and see responses
- Generate live reports that update as the underlying data or parameters change
How Streamlit compares
Streamlit alongside other open-source data app builders tools AI/TLDR tracks, ranked by GitHub stars.
| Tool | Stars | What it does |
|---|---|---|
| Streamlit | ★ 45k | Turn Python scripts into interactive data and ML web apps |
| Gradio | ★ 43k | A Python library for quickly building shareable web demos and UIs for machine learning models, APIs, and arbitrary functions. |
| Reflex | ★ 28.6k | A framework for building full-stack web apps entirely in Python, compiling component code to a React frontend and Python backend. |
| Dash | ★ 24.3k | A Python framework from Plotly for building analytical web dashboards and data apps with interactive charts and no JavaScript required. |
| marimo | ★ 21.5k | A reactive Python notebook stored as plain Python that can be run as a script or deployed as an interactive data app. |
| NiceGUI | ★ 15.9k | A backend-first Python UI framework built on FastAPI and Vue for creating web interfaces, dashboards, and internal tools. |
| Data Formulator | ★ 15.8k | A Microsoft Research tool that combines a UI with AI to help users create rich data visualizations through natural language and direct manipulation. |
| Mesop | ★ 6.6k | A Python UI framework, started at Google, for rapidly building AI demos and internal web apps using composable components. |