Languagelayer

Languagelayer

Powerful Language Detection JSON API for Developers
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{
   "success":true,
   "results":[
      {
         "language_code":"es",
         "language_name":"Spanish",
         "probability":23.312587636589,
         "percentage":100,
         "reliable_result":true
      }
   ]
}

Response example. If you want to see more check the documentation.

Free, powerful language detection JSON API for 173 languages, supporting single and batch requests, PHP, JavaScript, Python, Ruby, Java, and more.