Comparing Phoenix and Rails for building a fullstack web app
Hey folks, what’s up? I’ve been diving into Phoenix and Rails lately, and I wanted to share a casual rundown of what I’ve found.
Grab your favorite drink and let’s roll.
Why you might care
Both frameworks let you serve HTML, build APIs, and even add real time features. But they come from different worlds, so your choice really depends on what you value: performance, dev XP, community size…
12 points of comparison
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Language
- Rails runs on Ruby, which reads almost like English and is super beginner friendly.
- Phoenix is built with Elixir, a functional language on the Erlang VM, so you get actor model concurrency by default.
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Concurrency and performance
- Phoenix rides on the BEAM VM, so handling thousands of sockets or long lived processes is a breeze.
- Rails can scale too, but you’ll often set up extra threads, use a Puma cluster, or add gems like Sidekiq to match that level.
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Productivity and dev experience
- Rails is famous for being “batteries included”, like generators, built in conventions, scaffolding, etc. You can spin up a CRUD app in minutes.
- Phoenix has generators too, but it’s more minimal. You might wire up things manually, but you’ll still be flying after a few files.
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Templating and views
- Rails ships with ERB, and the community also loves Haml or Slim.
- Phoenix uses EEx, which feels a lot like ERB but leaner. Plus LiveView gives you reactive UIs with almost no JS.
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Real time support
- Phoenix Channels and LiveView are crazy powerful right out of the box.
- Rails ActionCable works, but I’ve seen it get flaky under high load and it’s a bit less mature.
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Ecosystem and community
- Rails has been around for ages; there’s a gem for literally everything.
- Elixir and Phoenix are newer, so fewer packages, but the community is tight and growing fast.
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Database and migrations
- ActiveRecord in Rails is super intuitive with its DSL and tons of extensions.
- Ecto in Phoenix is also a DSL but functional; queries feel explicit and you get compile time checks.
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Testing support
- Rails defaults to minitest, and many devs opt for RSpec.
- Phoenix uses ExUnit, which is simple, fast, and integrates nicely with testing Channels or LiveView features.
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Learning curve
- If you know OOP and Ruby syntax, Rails is a breeze.
- Phoenix might feel odd at first if you’re new to functional programming, but once you learn pipes and pattern matching, you’ll love it.
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Deployment and hosting
- Rails goes on Heroku, AWS Elastic Beanstalk, Dokku… no sweat.
- Phoenix apps compile to a BEAM release; you manage a node, but platforms like Gigalixir or Fly.io simplify it.
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Scaling
- Phoenix shines for real time heavy workloads, thanks to BEAM clustering.
- Rails scales nicely for traditional web requests, but you might spin up more dynos or servers under load.
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Hot code upgrades
- BEAM lets you swap code on the fly for zero downtime if you know what you’re doing.
- Rails can do phased restarts, but it’s not as seamless as a true hot upgrade.
Example code
Here’s a “Hello world” route in both:
# lib/my_app_web/router.ex scope "/", MyAppWeb do pipe_through :browser get "/", PageController, :index end # lib/my_app_web/controllers/page_controller.ex defmodule MyAppWeb.PageController do use MyAppWeb, :controller def index(conn, _params) do text(conn, "Hello from Phoenix") end end
# config/routes.rb Rails.application.routes.draw do root "pages#index" end # app/controllers/pages_controller.rb class PagesController < ApplicationController def index render plain: "Hello from Rails" end end
Wrap up
So yeah, Phoenix is your jam if you want blazing concurrency and real time magic.
Rails is perfect for rapid dev, huge libraries, and classic full stack CRUD apps.
Both rock, just pick the one that vibes with your team and project needs. Happy coding!