When comparing CircleCI vs Travis, the Slant community recommends Travis for most people. In the question“What are the best continuous integration tools?” Travis is ranked 2nd while CircleCI is ranked 3rd. The most important reason people chose Travis is:
Travis is free for all public repositories on Github.
Ranked in these QuestionsQuestion Ranking
Pro Quick setup
CircleCI excels with its setup process. All that's needed is a GitHub login and CircleCI automatically detects the settings for Ruby, Python, Node.js, Java and Clojure. The setup process is their most widely praised feature.
Pro Very fast parallel testing
Tests can be parallelized across multiple machines reducing test times drastically. They support up to 8-way parallelization. Additionally, CircleCI caches the build environment.
Pro Simple and intuitive GitHub integration
CircleCI can be connected to any project that is hosted on GitHub by logging in using the GitHub OAuth and adding the desired repository.
Whenever a new commit is pushed to GitHub, CircleCI runs the tests that have been already defined and if none of them fails, the build is deployed to the runtime environment.
Pro SSH support
Users can access the Virtual Machine via SSH and run commands.
Pro Easy configuration with YAML
In most cases CircleCI automatically get settings from your code. When it fails, edit circle.yml.
Pro Clean, intuitive UI
Circle CI's web UI is clean and easy to use.
It gives all the information for a single build in a feed and gives the explanation for each step of the build, what it's doing and what the step is related to. On the top it displays author information and the time and date when the build was started and finished.
This is all done by giving only the most essential information without clogging the screen.
Pro Supports 8 languages and 16 databases
It als has support for: MySQL, MongoDB, PostgreSQL, Cassandra, Riak, Redis, SQLite, Solr, CouchDB, ElasticSearch, Neo4j, Couchbase, Lucene, Sphinx, ThriftDB, Memcache.
Pro Headless browser support
Alongside latest Chrome, Firefox and Webkit (installed using xvfb), CircleCi supports the use of Selenium, PhantomJS as well as tools like Capybara and Cucumber.
Pro Support for Queues
Support for RabbitMQ, Beanstalk and Resque through Redis.
Pro Intelligent notifications
CircleCI can notify via email, Hipchat, Campfire and more. And it does so only when necessary.
Pro Can test many code pushes concurrently
You can push multiple batches of code concurrently.
Pro Supports 10 Continuous Deployment solutions
Support for Heroku, AWS, Engine Yard, dotCloud, Fabric, Nodejitsu, AppFog, Capistrano, Rockspace, Joynet.
Integration with Heroku is solid with the ability to automatically deploy or merge branches.
CircleCI is also very flexible with the deployment arrangement allowing SSH key management, deployment freedom including directly to a PaaS, using Capistrano, Fabric, arbitrary bash commands, or by auto-merging to another branch, or packaging code up to S3.
Pro Supports Docker
CircleCI can continuously deliver Docker images to hosts that support Docker containers.
Pro Free for open source projects
Travis is free for all public repositories on Github.
Pro Github integration
Travis registers every push to GitHub and automatically builds the branch by default.
Pro Easy to set up and configure
All that is needed to set up Travis is a configuration file (travis.yml) in the root of the repository where it will be installed and Travis takes care of the rest.
Pro Supports most technological stacks
Supports the most widely used technological stacks (Node, Ruby, PHP, Python etc...) for free.
Pro OSX & Ubuntu support
Travis' VM are built on Ubuntu 12.04 64 bit Server Edition, with the exception of Objective-C builds, which are based on Mac OS X Mavericks.
Pro Private repositories and personal support w/ TravisPro
Starting at $129 you can use TravisPro, that adds the option of closed-source, private, repositories and personal support.
Pro Multiple test environments for different runtime versions
Travis supports testing for different versions of the same runtime. All it takes is some lines in the
Pro Great community
Travis CI has a large and helpful community which is quite accepting to new users and provides a great number of tutorials.
Pro Supports more than a dozen languages
Pro Excellent website user experience
Con Changes the environment without warning
Unless you count forum posts as a warning. A mysql upgrade caused days of debugging.
Con Docker is way outdated on the VM provided
Currently (October 5th 2016), Docker installed on the VM is: 1.9.1-circleci-cp-workaround, build 517b158, and docker-compose is 1.5.2, build 7240ff3. docker-compose in particular is almost too old to be used.
Con Does not cache docker images
The way to fake it is to save the image on disk, in the cache folder (it tars it), and restore it afterwards. But in tests it was slower than not caching.
Con Only GitHub support
It does not support BitBucket. So it's not in list for companies using BitBucket private or public repositories.
Con Relatively expensive
Commercial plans for Travis are relatively expensive compared to other tools. They start at $129/month.
Con Non-free for private repos
Travis CI was first built to serve and help Open Source Projects, but now they also have added support for Closed Source which unfortunately is not free.
Con No Windows support
Travis can only run tests on Linux and OS X operating systems; running tests on Windows is not currently supported.