Shiny is an R framework for building interactive web applications and dashboards directly from R, without requiring JavaScript or frontend development.

Core idea

Shiny allows you to:

  • define a UI (user interface)
  • define a server function (logic and computation)
  • connect them through reactivity

Reactivity means outputs automatically update when inputs change.

What it enables

  • Interactive dashboards (filters, sliders, selectors)
  • Data exploration tools
  • Real-time model outputs
  • Internal tools for analysts or stakeholders
  • Lightweight web apps for sharing analysis

Typical components

  • Inputs → user controls (dropdowns, sliders, date ranges)
  • Outputs → plots, tables, text
  • Reactive expressions → computations that update automatically

Relation to tidyverse

  • tidyversedata preparation and transformation
  • Shiny → presentation and interaction layer

They are often used together:

  • tidyverse prepares and aggregates the data
  • Shiny exposes it through an interactive interface

Conceptual view

Shiny acts as a wrapper around analytical workflows, turning static R analysis into interactive systems.

Comparison to Python ecosystem

R Shiny is similar to:

When to use Shiny

  • You need to share analysis interactively without building a full web app
  • Stakeholders need self-service exploration
  • You want a fast path from analysis → dashboard

Free hosting options

1. Local (development)

  • Runs on your machine
  • Access via browser (localhost)
  • Not shareable externally

2. shinyapps.io (free tier)

  • Managed hosting platform by Posit
  • Deploy directly from RStudio
  • No infrastructure required

Characteristics:

  • Public URL for sharing
  • Limited compute and usage hours
  • Apps may sleep when inactive

Conceptual summary

Shiny provides a lightweight path from R analysis to interactive dashboards, and the free tier (shinyapps.io) allows simple deployment and sharing via a public URL without managing infrastructure.