When comparing Travis vs Codeship, the Slant community recommends Codeship for most people. In the question“What are the best continuous integration tools?” Codeship is ranked 3rd while Travis is ranked 7th. The most important reason people chose Codeship is:
Support for public and private GitHub and BitBucket repositories. It also has support for multi-user teams.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Free for open source projects
Travis is free for all public repositories on Github.
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 Github integration
Travis registers every push to GitHub and automatically builds the branch by default.
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 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 travis.yml
file.
Pro Supports more than a dozen languages
Support for C, C++, Clojure, Erlang, Go, Groovy, Haskell, Java, JavaScript, Perl, PHP, Python, Ruby and Scala.
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 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 Excellent website user experience
Pro GitHub & Bitbucket integration
Support for public and private GitHub and BitBucket repositories. It also has support for multi-user teams.
Pro Keeps it simple. Doesn't allow too many "tricky" things which means builds are generally very stable once they are up and going.
Pro Headless browser support
Alongside latest Chrome and Firefox, Codeship supports the use of Selenium, PhantomJS, CasperJS as well as tools like Capybara.
Pro Build status GIF
There's a continuously updated GIF of the build status of the repository allowing you to determine whether build was successful or not.
Pro Support for multiple tools, languages and databases
Support for e-mail, HipChat, Slack, Campfire, Flowdock, Grove, Webhook, Github Status API.
Support for Ruby, Python, Node, Dart, PHP, Java, Scala, Groovy, Clojure, Go.
Support for: PostgreSQL, MySQL, MongoDB, Redis, Memcached, ElasticSearch, SQLite.
Pro Supports 7 cloud providers
Support for AWS, Digital Ocean, Rackspace, Google Compute, Joyent, Softlayer, Openstack.
Pro Docker support
Pro Simple deployments with a choice of 5 deployment tools
Support for Capistrano, Fabric, Chef, Puppet, Ansible and allows for writing your own scripts to deploy and manage your infrastructure.
Pro Supports 10 hosting providers
Support for Heroku, Engine Yard, Nodejitsu, dotCloud, App Engine, AppFog, Modulus, Openshift, Cloud Foundry, Fortrabbit and you can also run your own script to deploy anywhere.
Pro FTP, SFTP, SCP, RSYNC and SSH support
You can use FTP, SFTP, SCP, RSYNC and SSH for Continuous Deployment.
Pro Code Climate & Coveralls support
Automated code review for RoR and JavaScript and test coverage history and statistics with Code Climate and Coveralls.
Cons
Con Only partial .NET support
.NET support is limited to .NET Core and Mono.
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.
Con Doesn't support git modules
If repo contain private submodule - build will fail, no way to add your private key.
Con Any time you ask support for help on Codeship basic (which isn't free anyway), they will just try to up sell you to Pro version.
Con No Global variables that can be shared amongst all projects.
Con Environment variables are exposed. Any keys or secrets can just be copied.
No option to mask them unless you reduce permissions for those users. Developers need to be able to modify a job but probably shouldn't be able to copy a production api key. Just needs one more level of permissions here.
Con Too many permissions on Bitbucket
When registering with Bitbucket Codeship it requests way to many permissions, even "Read and write to your team's projects and move repositories between them". Before giving all these permissions you have to be sure you can trust this service.
