When comparing Ruby on Rails vs Symfony, the Slant community recommends Ruby on Rails for most people. In the question“What are the best backend web frameworks?” Ruby on Rails is ranked 9th while Symfony is ranked 24th. The most important reason people chose Ruby on Rails is:
The sheer scale and massive number of developers using Rails has produced a large number of guides, tutorials, plugins, documentation, videos and anything that can help new and old Rails developers.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Massive community with lots of tutorials and guides
The sheer scale and massive number of developers using Rails has produced a large number of guides, tutorials, plugins, documentation, videos and anything that can help new and old Rails developers.
Pro Many plugins (gems) available
There are many third-party plugins (Ruby gems) available for Rails development. The larger ones and those that have a lot of downloads and users are very well documented and easy to use.
Pro Ruby is a nice readable language
Ruby has a very clean syntax that makes code easier to both read and write than more traditional Object Oriented languages, such as Java. For beginning programmers, this means the focus is on the meaning of the program, where it should be, rather than trying to figure out the meaning of obscure characters.
presidents = ["Ford", "Carter", "Reagan", "Bush1", "Clinton", "Bush2"]
for ss in 0...presidents.length
print ss, ": ", presidents[presidents.length - ss - 1], "\n";
end
Pro Good conventions
MVC is a great starting point, and perfect for APIs. You'll rarely if ever have to wonder "where should I put this code?"
Pro Small projects are very easy and it's possible to finish one in very little time
The large number of documentation, tutorials, videos and guides which help new developers who are just starting with Rails make it seem very easy to create a small and simple application by relying on code generation and components that come out of the box with Rails.
Pro Cool language
Pro Supported on every major cloud or VPS hosting service
Rails is supported on every major Cloud hosting service nowadays. There are also countless tutorials that help developers deploy their Rails apps if there are any problems on the way.
Pro Meta-programming capabilities
Pro Open Source
Symfony is open source and released under the MIT license.
Pro Easy debugging with a built-in debug toolbar
Symfony comes with a built-in toolbar that helps developers debug their applications during the development phase.
The toolbar is also extendable and new components, called panels can be added if needed to help with the debugging process.
Pro Great plugin ecosystem
One of the greatest strengths of Symfony is it's amazing and large plugin ecosystem, which comes as a result of it's large and dedicated community. Having a large number of plugins means less development time and more productivity.

Pro Highly active community
Symfony has one of the most active communities out of all the PHP frameworks. This is shown by the high number of commits made every day in the GitHub repo.
Pro Teaches you good practices
Symfony makes you be a better programmer. You have to deal with the latest object-oriented design patterns such as service-oriented architecture, dependency injection, interface abstraction, and so on.
Pro Uses YAML/XML/PHP/Annotation
Symfony makes use of XML, YAML or PHP annotations to create configurations in order to tell Doctrine on how properties of a certain class should be.
Pro Powerful event system
Symfony has a powerful built-in event system that allows you to add flexibility to applications and makes it easier to maintain the codebase down the road.
Pro Great templating engine
Uses Twig, which is a simple and easy to learn templating language that can also be used as a standalone engine, outside the framework.
Pro Uses Doctrine ORM
Symfony makes use of the Doctrine ORM to add an abstraction layer over the database in order to maintain flexibility without having unnecessary code duplication.
Cons
Con Learning curve seems low at first, but starts becoming steeper
Rails' simplicity is deceptive. It's learning curve is really low at first, and the huge number of tutorials and guides out there for starting with Rails make it even easier. But it starts getting harder and harder as apps become more complicated. If good code conventions and OO design are not followed, then the codebase will be all over the place and it becomes impossible to maintain it.
Con Too much magic
So much behavior is implemented with dynamic behind-the-scenes changes to existing classes that obscure bugs are way too common. Conflicting interactions between multiple plugins that both try to change the same objects are a particularly pernicious example.
Con Too much convention
Con Not a very popular language outside of web development
Con Bad performance
Among the slowest frameworks. If you want to scale, you will have to migrate to another land.
Con Settings
Too many configurations.
Con Very hard to install
Setting it up on webhost without a console is difficult.
Con Promotes bad development practices
Such as annotations via comments.
Con Doctrine ORM
Symfony Standard Edition, which is the most widely used distribution, comes integrated with Doctrine, the most resource hogging ORM library.
Con You need a lot of files to display a single page
For a simple hello world page you need about 5 files.
