When comparing IBM Watson Tone Analyzer vs Aylien, the Slant community recommends IBM Watson Tone Analyzer for most people. In the question“What are the best sentiment analysis APIs for texts?” IBM Watson Tone Analyzer is ranked 2nd while Aylien is ranked 3rd. The most important reason people chose IBM Watson Tone Analyzer is:
Watson is a bit of a one stop shop for tone analysis. It's packages are self contained, so setup is simple and can be injected into nearly any app. There aren't any dependencies and setup can be done via the command line by simply setting up an endpoint and a user engagement point. All setup steps are well documented [here](https://console.bluemix.net/docs/services/tone-analyzer/getting-started.html#gettingStarted).
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Pros
Pro Easy to set up
Watson is a bit of a one stop shop for tone analysis. It's packages are self contained, so setup is simple and can be injected into nearly any app.
There aren't any dependencies and setup can be done via the command line by simply setting up an endpoint and a user engagement point. All setup steps are well documented here.
Pro Globally used with a good community
Watson is one of the more common tone analyzers and is used worldwide. The community surrounding it is fairly large, so any questions you have can be directed to an educated userbase. You can find Watson developers on StackExchange, the IBM forums, and they even have a Slack channel.
Pro Can detect emotion through both slang and emoticons
Pro Developer friendly
IBM provides SDK's for Android, Java, Node.js, Python, Salesforce, Swift, .NET, OpenWhisk, Unity, Go, PHP, Ruby, and Scala.
Using the service is easy, simply passing the input text to the service via GET or POST, and the service returns an analysis in JSON format.
Pro Good accuracy
Watson was tested against standard emotion sets like SEMEVAL and ISEAR, and was found to be around 41-68% accurate, beating out the best reported accuracy of the state of the art models which came in at around 37-63%.
You can read more about Watson's accuracy here.
Pro Easy setup
There aren't any dependencies, all you need to do is make a Post or Get request from the API and you're off.
Pro Good accuracy
As of 2015, Aylien stated that the accuracy of their service was around 80%.
Pro Supports six spoken languages
Aylien provides full support for English, and partial support for German, French, Italian, Spanish, and Portuguese.
You can see the full list of language support here.
Pro Provides SDKs for a number of popular programming languages
Aylien provides an SDK for JS, Python, PHP, Java, Ruby, Go, and C#. Using an SDK allows you to embed Aylien's functionality within your code instead of making an HTTP Get or Post request.
Pro Free access for users with less than 1000 API calls per day
Cons
Con Limited non-English support
Some users have reported that Watson has trouble with other languages. Watson only officially supports English and French, so its support for other languages can be limited. Users have reported trouble with the Spanish tool specifically, saying that it's slow and unresponsive.
Con Very little existing information about accuracy
Investing a lot of time into working with Aylien may prove risky due to the lack of hard statistics online.