TensorFlow Playground

A web-based tool by Google that allows users to experiment with deep learning models in their browser.

IBM Watson Studio

IBM's AI platform that offers free access to a range of AI tools and services, including data analysis, machine learning, and natural language processing.

H2O.ai

H2O.ai's Driverless AI Community Edition provides a free web portal for automated machine learning tasks, including feature engineering, model building, and deployment.

Google Cloud AI Platform Notebooks

Google's AI platform provides free access to JupyterLab notebooks for developing and running machine learning models.

Microsoft Azure Machine Learning Studio

Azure's web-based AI platform offers a free tier with drag-and-drop tools for building, deploying, and managing machine learning models.

OpenAI Playground

OpenAI's web portal allows users to experiment with language models and generate text using various prompts.

DeepAI

DeepAI provides free access to several AI tools, including image and text recognition, language translation, and sentiment analysis.

Algorithmia

Algorithmia offers a free tier that provides access to their AI marketplace, where users can discover and utilize various pre-trained AI models and algorithms.

Clarifai

Clarifai's free plan provides access to their computer vision APIs, allowing users to analyze and tag images.

Aylien Text Analysis API

Aylien offers a free tier of their API, which provides text analysis capabilities such as sentiment analysis, entity recognition, and summarization.

MonkeyLearn

MonkeyLearn's free plan allows users to perform text classification and sentiment analysis tasks using their API.

ParallelDots

ParallelDots offers a free tier for their AI-powered text analysis API, including sentiment analysis, intent detection, and keyword extraction.

Wit.ai

Facebook's Wit.ai platform provides free access to their natural language processing tools, allowing developers to build conversational AI applications.

Dialogflow

Google's Dialogflow offers a free tier for their natural language understanding platform, enabling users to create chatbots and voice assistants.

RapidAPI

RapidAPI is an API marketplace that provides access to various AI APIs, many of which offer free tiers for experimentation and development purposes.

Please note that the availability and features of these portals may change over time, so it's always a good idea to visit their respective websites for the most up-to-date information on their offerings.