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Sinatra

A small Ruby library for building web apps and APIs with minimal code.

GitHub Download source
Stars
12.5k
Forks
2.1k
Licence
MIT
Language
Ruby
Last update
4 months ago
Type
Library

What it is

Sinatra is a Ruby library that lets you write a web application with just a few lines of code. You define routes that match web addresses and HTTP methods, and each route runs a block of Ruby that returns a response. It is commonly used for small web apps, quick prototypes, and simple APIs.

  • Create a route such as get '/' that returns a message in the browser
  • Serve dynamic pages using templates like ERB or Haml
  • Define JSON or other endpoints that respond to specific HTTP methods
  • Handle named and wildcard URL parameters such as /hello/:name
  • Use sessions, filters and error handlers for a small web app

Great for

  • Ruby developers who want a small, readable web app or API
  • Quick prototypes and small internal tools
  • Learning how web routes and requests work in Ruby
  • Projects that only need a few endpoints rather than a full framework

Not ideal for

  • Large, full-featured applications that need built-in conventions for models, migrations and admin panels (the README describes Sinatra as a minimal DSL, so bigger apps need to assemble more parts themselves)
  • Non-Ruby teams, since the project is written for Ruby and requires it
Step-by-step guide: how to use SinatraInstall, first run, examples, tips and FAQs
Rails vs SinatraGrape vs Sinatra

How to get it

  1. 1

    Install with a package manager

    You'll need: Ruby

    Install the gems

    gem install sinatra rackup puma
  2. 2

    Run it

    • Save the example code as myapp.rb
    • Run: ruby myapp.rb
    • Open http://localhost:4567 in your browser
    • Restart the server after each code change, or use a reloader such as rerun
  3. 3

    Get the most out of it

    • Use Sinatra::Base for modular apps with more structure
    • Add template engines such as Haml, ERB or Slim for HTML output
    • Use the configuration settings and attack protection options described in the README
    • Use rack-unreloader or rerun to avoid manual restarts during development

Downloads

Source code (.zip)main branch · straight from GitHubOfficial website & docssinatrarb.com

Strengths

  • Very short, readable syntax: a working app fits in a few lines
  • Supports many template languages listed in the README
  • Runs on Rack, a standard Ruby web interface, so it works with many servers

Trade-offs

  • Minimal by design, so you add libraries yourself for things like databases or auth
  • Code changes need a server restart or a reloader tool, as the README notes

How it compares

ProjectStarsTypeLevelUpdatedBest for
sinatra (this)12.5kLibrarybeginner4 months agoRuby developers who want a small, readable web app or API
rails58.8kFrameworkintermediate4 days agoDevelopers building database-backed web applications in Ruby
echo32.8kLibraryintermediate6 days agoGo developers building REST APIs or backend services
hono32.8kLibrarybeginner5 days agoDevelopers writing TypeScript or JavaScript HTTP APIs
vapor26.2kLibraryintermediate4 days agoSwift developers who want to build backend services in the same language as their iOS or macOS apps
core19.2kLibraryintermediate6 days agoDevelopers who want a structured, batteries-included framework on Node.js

Stats synced from GitHub. The assessment above was drafted with AI from the project's README on 2026-10-29 and may miss recent changes — check the README before relying on a command. MIT licence: free to use, modify and distribute, including commercially, as long as you keep the copyright notice.