Sentiment API

Frequently Asked Questions

• Can I use the Sentiment API for commercial purposes?

  Yes, but you must have a premium subscription. Commercial use of the Sentiment API is not permitted on the free tier. See our pricing page to choose a plan that fits your needs.

• How do I get an API key and start using the Sentiment API?

  Sign up for a free account to instantly get your API key, then pass it in the X-Api-Key header on every request. The documentation above includes ready-to-run examples in cURL, Python, JavaScript, Node.js, and more.

• What happens if I exceed my quota for the month?

  Your API requests will simply be denied once you hit your monthly quota — you will never be charged more than the plan you signed up for. To increase your quota, you can upgrade your plan any time on our pricing page.

• What happens if a request to the Sentiment API fails?

  The API responds with a standard HTTP status code and a JSON error message describing the problem. See our error codes reference for the full list of codes and how to resolve each one, or contact support if you need help.

• What does the score field represent and how is it different from the sentiment field?

  The score is a numeric value from -1 to 1, where 1 is the most positive, -1 is the most negative, and 0 is neutral, while the sentiment field maps that score to a label such as POSITIVE, WEAK_POSITIVE, NEUTRAL, WEAK_NEGATIVE, or NEGATIVE. If you also need to compare how alike two pieces of text are, see the Text Similarity API.

• Is there a length limit on the text I can analyze?

  Yes, the required text parameter accepts a maximum of 2000 characters per request, so longer documents should be split into smaller chunks before calling the endpoint. You can review usage limits on the pricing page.

• Can I detect the language of the text before running sentiment analysis?

  The Sentiment endpoint only returns score, text, and sentiment and does not report language, so to identify the language first use the Text Language API. You can also browse other text tools in the API catalog.

• How do I call the endpoint to analyze a phrase?

  Send a GET request to https://api.api-ninjas.com/v1/sentiment with your phrase in the text query parameter (URL-encoded) and your key in the X-Api-Key header; for example ?text=I%27m%20loving%20it returns a POSITIVE sentiment. If a call fails, consult the error codes reference.