Dash (Plotly)
What it is: Python framework for building analytical web applications. More powerful than Streamlit, production-ready.
What It Does Best
Production apps. Built for real applications, not just demos. Handles authentication, caching, deployment.
Full control. More complex than Streamlit but more customizable. Build exactly what you need.
Plotly integration. Native Plotly charts. Beautiful, interactive visualizations built-in.
Key Features
Reactive components: Declarative callbacks link inputs to outputs
Plotly graphs: Full integration with Plotly charting library
Custom components: Build React components, use in Python
Multi-page apps: Complex navigation and routing built-in
Production features: Authentication, caching, async callbacks
Pricing
Open source: Free
Dash Enterprise: $950+/month (deployment, auth, advanced features)
When to Use It
✅ Production analytical applications
✅ Need custom layouts and interactions
✅ Willing to write more code for flexibility
✅ Real users, not just demos
✅ Require authentication and user management
When NOT to Use It
❌ Quick prototypes (Streamlit faster)
❌ Non-analytical web apps (use Django/Flask)
❌ Need simplest possible tool
❌ Team unfamiliar with callbacks and reactive programming
❌ Simple static reports (overkill)
Common Use Cases
Business intelligence dashboards: Interactive KPI dashboards for executives
Data science applications: ML model demos, parameter tuning interfaces
Real-time monitoring: Live data feeds with updating charts
Internal tools: Analytics apps for data teams and analysts
Client-facing analytics: Embedded dashboards for SaaS products
Dash vs Alternatives
vs Streamlit: Dash more control, production-ready; Streamlit simpler, faster prototyping
vs Shiny: Dash better Python support; Shiny better for R users
vs Flask/Django: Dash specialized for analytics; Flask/Django better general web apps
Unique Strengths
Declarative syntax: Clean callback-based reactivity
Plotly ecosystem: Seamless integration with industry-leading charts
Production-ready: Authentication, caching, deployment built for scale
Pure Python: No HTML, CSS, or JavaScript required
Bottom line: Streamlit for demos, Dash for production. More complex but scales better. Choose this when the app matters to your business.