Top 10 AI & Machine Learning APIs for Developers (2021)

What is Machine Learning?

An Application Programming Interface is a set of subroutines, functions, and procedures that help a developer create application software that accesses features of an underlying service that provides the API.

Machine learning, on the other hand, is a field of artificial intelligence that employs statistical techniques to realize a perception of progressive improvement in performance of a computer in performing a specific task without explicit programming.

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Machine learning APIs, therefore, are services that provide a set of functions and procedures for developers to use.

At the core of these functions, machine learning APIs and processes are statistical techniques that are used to bring about a perception of learning in the programs that these APIs are used in.

Top Machine Learning APIs

Here is a list of machine learning APIs & machine learning platforms that we reviewed on RapidAPI worth mentioning:

1. AmazonML API

Amazon Machine Learning is among the best machine learning APIs available.

It acts as a managed service for generating predictions.

List of AmazonML endpoints

• add tags</code – adds one or more tags to an object with each tag consisting of a key and an optional value.
• createBatchPrediction</code – generates predictions for a group of observations.
• createDataSourceFromRDS</code – (BETA) creates a DataSource object from an Amazon Relational Database Service (Amazon RDS).
• createRealtimeEndpoint</code – creates a real-time endpoint for the MLModel.
• deleteDataSource – assigns DELETED status to a DataSource, making it unusable

How to acquire an AmazonML API key

1. Navigate to the Amazon Console
2. Log in or create a new account
3. Hover over your username for the dropdown and select ‘My Security Credentials’
4. Click on ‘Groups’ and create a new Group with the necessary polices
5. Create a new user and assign to an existing group
6. After creating a user you will see credentials and your API key

AmazonML API Pricing

According to their pricing page:

• Pay as you go (only for what you use).
• Amazon charges an hourly rate for the compute time & the number of predictions generated for your application.
• Pricing is also dependent on region.

2. Aylien Text Analysis API

The Text Analysis API by Aylien is used for:

• Natural Language Processing,
• Information Retrieval,
• and Machine Learning

This API provides tools that allow developers to extract meaning and insights from documents.

List of endpoints

• Microformats</code – extract microformats from URLs.
• Language Detection</code – detects the main language a document is written in and returns it in ISO 639-1 format, from among 62 different styles.
• Hashtag Suggestion</code – suggests hashtags describing the document.
• Entity Extraction</code – extracts named entities (people, organizations, and locations) and values (URLs, emails, telephone numbers, currency amounts, and percentages) mentioned in a body of text

How to acquire an Aylien API Key.

Through RapidAPI, you don’t need an Aylien API key.

Once you’re subscribed to a pricing plan, you will use your RapidAPI API key to make your requests to the Aylien API:

1. Log in or Sign up for a new account.
2. Navigate to the pricing page and select a pricing tier.

Your RapidAPI key is provided with every code snippet as the “X-Mashape-Key” and can also be found in your RapidAPI Dashboard under the “Security” tab of your application.

Aylien API Pricing

Test Analysis API works on a subscription plan basis, where a client is charged as per to daily or per minute limits.

There’s also a free plan that allows up to 1,000 calls per day ($0.01 per extra).

3. MicrosoftContentModerator

MicrosoftContentModerator allows for machine-assistance to moderate text and images.

List of endpoints

• addImageInlist – add an image to your image list.
• createImageList – create an image list
• addTerm – add a term in a list
• createTermList – create a term list
• deleteTerm – delete a term from the list
• deleteImageList – delete a list
• deleteImageFromList – delete an image from your image list
• deleteAllTermsFromList – delete all terms from the list
• deleteAllImagesFRomList – delete all images from your list

How to acquire a Microsoft API key

To obtain a Microsoft Content Moderator API key, one has to perform two tasks:

1. Subscribe to the Content Moderator APIs via the Azure portal.
2. Sign up for Content Moderator Review tool.
3. Via settings, navigate to the credentials section to grab your API Key.

Microsoft API Pricing

There are four main pricing tiers:

• 0 – 1,000,000 transactions at $1 per 1,000 transactions.
• 1,000,000 – 5,000,000 transactions at $0.75 per 1,000 transactions.
• 5,000,000 – 10,000,000 transactions at $0.60 per 1,000 transactions.
• 10,000,000 – 20,000,000 transactions at $0.40 per 1,000 transactions

4. IBMWatsonSTT API

A speech to text machine learning service that transcribes audio into text.

List of endpoints

• addCorpus – add a single corpus text file of new training data to the custom language model.
• checkJobs – returns status and ID of all outstanding jobs associated with the service credentials with which it is called.
• createJob – creates a situation for a new asynchronous recognition request.
• createSession – establishes a session and locks recognition requests to that engine.
• deleteCustomodel – delete an existing custom language model.
• createCustomModel – creates a new custom language model for a specified base language model.
• checkSingleJob – returns status and ID of all outstanding jobs associated with the service credentials with which it is called

How to acquire an IBM Watson API key

1. Register at the IBM Bluemix Console.
2. After logging in, choose Speech To Text from the services section.
3. Connect Speech To Text to your application at the left side, choose a pricing plan, and click on ‘Create’ button at the bottom of the page.
4. Click on ‘Service Credentials’ tab to see your username and password.

IBM Watson Pricing

• Enterprise: 100,000 API calls per month for $100
• Enterprise 25M: 25 million monthly API calls for $10,000
• Enterprise 1B: 1 billion monthly API calls at $160,000
• Hybrid Professional: 100,000 API calls at $55
• Hybrid Enterprise: 100,000 API calls at $44
• Native: free

5. Kairos API

This machine learning API can find and recognize faces in an image that you upload through the API.

List of endpoints

• deleteEmotionalAnalysis: deletes media results
• deleteSingleGallery: remove a gallery and all of its subjects
• compareFaces: finds a face from a photo and compares it with looks in the gallery.
• addFacesToGallery: finds faces from a picture and adds them to the gallery

How to acquire a Kairos API key

1. Visit the Kairos dashboard.
2. Log in or sign up for a free account.
3. Switch to the APPLICATIONS endpoint.
4. Click on the “Create New Application” button.
5. Fill in all the required fields and click on “Create Application”.
6. Grab the Application ID as your appID and Applications keys as appKey.

6. MonkeyLearn API

This API automates text classification with machine learning models.

List of endpoints

• classify – allows you to perform the classification of many text samples using only one request to a custom or public module.
• classifyMulti – will enable you to play the classification of many text samples using just one application to a tradition or public module that you have already installed. For this endpoint to work, the module has to be set as a Multilabel Module.
• createClassifier – creates a new classifier.
• createClassifierCategory – creates a new category on the tree. You have to select a name and a parent category.
• deleteClassifier – deletes a classifier.
• deleteClassifierCategory – deletes a group from the tree.
• deployClassifier – deploys the current sandbox classifier as a live classifier. The old live classifier will be overwritten.
• executePipeline – executes the existing pipeline.
• extractEntities – extract entities from a list of texts using Named Entity Recognition

How to acquire a MonkeyLearn API key

1. Sign in to MonkeyLearn.
2. Navigate to the API Keys section.
3. Generate your API token.

MonkeyLearn API Pricing

• Free plan: 300 queries per month
• Team plan: 30,000 questions at $299 per month
• Business plan: 300,000 questions at $999 per month
• Enterprise plan: number of queries on as per to demand basis

7. ApiAI API

This API aids in building intelligent natural language bots powered by AI.

List of endpoints

• addContext – adds new active contexts to the specified session.
• clearContexts – deletes all contexts from the specified session.
• deleteContext – deletes the specified context from the specified session.
• getContext – retrieves the specified context for the specified session.
• getContextx – retrieves the list of all currently active contexts for the specified session.
• query – used to process natural language, either in the form of text or a sound file.
• textToSpeech – used to perform text-to-speech – generate speech (audio file) from text

How to acquire an ApiAI API key

1. Navigate to https://console.api.ai
2. Click on the general section under settings.
3. Copy your access_token.

ApiAI Pricing

• Free standard edition: unlimited text query requests at three requests per second.
• Pay as you go enterprise edition: unlimited text query requests at $0.002 per request at ten queries per second

8. WitAI

The WitAI API is used to create AI-powered bots that can talk like real people.

List of endpoints

• createEntity – create a new entity with the given attributes
• deleteEntity – permanently remove a body
• getAudioMeaning – return the meaning extracted from an audio file
• getBotNextStep – return what the bot needs to do next
• getEntities – returns a list of objects for the app

How to acquire a WitAI API key

1. Login to your Wit.Ai console
2. Choose an app or create a new one by clicking the “+” in the top right corner.
3. Go to the app settings
4. Copy and save your Server Access Token.

WitAI Pricing

WitAI is an open source machine learning API and is free to use.

9. AlchemyText

This API performs analysis on text for sentiment and broader concepts.

List of endpoints

• extractDatesFromText – get dates from plain text
• extractDatesFromUrl – get dates from web pages
• getAuthorsFromHtml – get author names from an HTML document
• getAuthorsFromUrl – get author names from web pages

How to acquire an Alchemy Text API key

1. Navigate to the AlchemyAPI and register your app.
2. Choose “Natural Language Understanding” from the categories.
3. Connect “Natural Language Understanding” to your application at the left side, choose a pricing plan, and click on ‘Create’ button at the bottom of the page.
4. Click on ‘Service Credentials’ tab to see your apiKey.

10. TrustServista Text Analysis

The Text Analysis API by TrustServista is used for:

• language detection,
• summarization,
• webpage content
• and metadata extraction.

List of endpoints

• Compare – compare semantics similarities between two URLs
• Entities – extract named entities from a given URL
• Language – detect the expression of raw text or a given URL
• Metadata – retrieve metadata from web pages

How to acquire a TrustServista API key

Subscribe to a pricing plan and use your RapidAPI API key to make your requests to the Aylien API:

1. Log in or Sign up for a new free account.
2. Navigate to the pricing page and select a pricing tier.

Your RapidAPI key is provided with every code snippet as the “X-Mashape-Key” and can also be found in your RapidAPI Dashboard under the “Security” tab of your application.

TrustServista API Pricing

• Free Tier starting out with 10,000 monthly calls.
• Pro Tier starting out at $69.99 with 40,000 monthly calls.
• Ultra Tier starting out at $179.99 with 100,000 monthly calls.
• Mega Tier starting out at $349.99 with 250,000 monthly calls.

Related Machine Learning APIs

Here are some more APIs in the Machine Learning category:

• Google Safe Browsing API – check URLs against Google’s constantly updated lists of unsafe web resources.
• Nexosis API – Machine Learning for Developers.
• Imagga API – Automate the process of analyzing, organizing and searching through large collections of unstructured images.

Summary: Best Machine Learning APIs & Software

Do you agree with our list? What do you think is the best machine learning API? Let us know in the comments below.