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20 Powerful APIs That Will Supercharge Your Javascript Apps

July 10, 2021 295 Views

One of the many factors that contribute to JavaScript’s popularity is its low barrier to entry. Because of its ease of use, it has become one of the most popular programming languages for developing web applications today. And, while there are numerous remarkable JavaScript frameworks available that claim to make app development easier, none of them come close to Sencha Ext JS for turbocharging your applications.

The Sencha Ext JS JavaScript framework is one of the most powerful available. This is because Sencha Ext JS is the most comprehensive JavaScript framework currently available for building data-intensive, cross-platform web and mobile applications for any modern device. It includes 140+ pre-integrated and tested high-performance UI components that are fully supported and designed to work together seamlessly over the lifetime of the application.

That said, for all of its use cases, JavaScript is an interpreted language. With the heavy demand in today’s world for seamless and fast applications, Sencha Ext JS supports Rest APIs to give it a performance edge. With the REST framework in Sencha Ext JS, you can easily access APIs to offload processing and turbocharge your web apps. To find out the basics, head over and check out the Sencha Ext JS documentation for making a REST API call.

In this article, you’ll learn about the 20 Powerful APIs that are useful for Javascript App Development. There are literally thousands of REST APIs available for developers to use, but we chose the top 20 that are extremely useful so that you can use them to improve the performance and functionality of your Javascript apps.


Let’s start with ipstack and geolocation. The ipstack API is a powerful, real-time IP to geolocation API capable of looking up accurate location data and assessing security threats originating from risky IP addresses. It delivers results within milliseconds in JSON or XML format. With this API, you can locate website visitors at first glance and adjust your user experience and application accordingly.


Next, you can detect any browser, device and OS in real-time with userstack. The easy-to-use REST API interface lets you parse User-Agent strings to accurately gauge where your traffic is coming from and what devices they are using. Implementing the JSON/XML API into your front or back end system gives you all the tools you need to take control of your website’s or application’s user experience and understand the customer journey that goes with it.


The positionstack API is a straightforward and reliable solution for forward and reverse geocoding. Positionstack covers more than 2 billion places and addresses worldwide. Its results can be delivered in JSON, XML or geocode-specific GeoJSON. Also, Average API response times range between 10ms and 100ms depending on the size of your request.


Languagelayer offers you a unique and simple way to automate language detection. It is a simple and powerful REST API built to efficiently match text of any length to its corresponding language, cross reference single words, expressions and grammatical constructions, as well as take into account accents, dialects and other linguistic deviations.


ipapi provides another easy-to-use geolocation API interface that lets you look at IPv4 and IPv6 addresses and the information associated with them. For each IP address processed, the API returns more than 45 unique data points, such as location data, connection data, ISP information, time zone, currency and security assessment data.

This API is REST-based, it makes lookup requests using straightforward HTTP GET URLs and returns results are returned in lightweight JSON or XML format within a matter of a few milliseconds.

turbocharge your app with ipapi


Mailboxlayer offers a simple REST-based JSON API you can use to thoroughly check and verify email addresses right at their point of entry into your system.

In addition to checking syntax, Mailboxlayer verifies the actual existence of an email address using MX-Records and the Simple Mail Transfer Protocol (SMTP). It also detects whether or not the requested mailbox is configured to catch all incoming mail traffic. The mailboxlayer API links to several regularly updated databases that contain all available email providers, which simplifies the separation of disposable (e.g. “mailinator”) and free email addresses (e.g. “Gmail”, “yahoo”) from individual domains.


Vatlayer is a simple JSON-based REST API that validates VAT numbers, retrieves all or single EU VAT rates based on IP address or country code, and converts prices in compliance with EU VAT rates and types.


NumVerify offers a full-featured yet simple RESTful JSON API for national and international phone number validation and information lookup. It supports a total of 232 countries around the world.

NumVerify processes requests in real-time, cross-checks numbers with the latest international numbering plan databases and returns results in handy JSON format enriched with useful carrier, geographical location and line type data.


The mediastack API provides a powerful, scalable yet easy-to-use REST API interface that delivers worldwide live and historical news data in handy JSON format. The API comes with a single news HTTP GET endpoint and has a series of parameters and options you can use to narrow down your news data results.


The coinlayer API delivers accurate exchange rate data for more than 315 cryptocurrencies in real-time. Coinlayer gathers Crypto data from some of the largest cryptocurrency exchanges It makes requests using HTTP GET and returns data in straightforward JSON format. Thanks to a refined fallback algorithm availability, the consistency and reliability of crypto data returned by the coinlayer API is at the highest level.

aviationstack API gives you real-time flight data


The aviationstack API was built to provide a simple way to access global aviation data for real-time and historical flights. It also allows you to tap into an extensive data set of airline routes and other up-to-date aviation-related information. Aviationstack makes REST API requests using a straightforward HTTP GET URL structure and responds in lightweight JSON format.


Currencylayer is a simple REST API that serves real-time and historical exchange rates for 161 world currencies. It delivers currency pairs in a universally usable JSON format that is compatible with any of your applications.

Currencylayer also retrieves spot exchange rate data from several major forex data providers in real-time. It validates, processes and delivers the information hourly, every 10 minutes, or even within the 60-second market window.


Screenshotlayer is a lightweight REST API that takes high-quality PNG, JPEG & GIF website screenshots at unparalleled speeds and through a simple interface.

To ensure the highest possible level of image resolution, this API relies on a powerful rendering engine capable of processing, storing and returning all sorts of website content within just a few seconds.

Fixer API

Powered by 15+ exchange rate data sources, the Fixer API can deliver real-time exchange rate data for 170 world currencies. The API comes with multiple endpoints, each serving a different use case. Endpoint functionalities include getting the latest exchange rate data for all or a specific set of currencies, converting amounts from one currency to another, retrieving Time-Series data for one or multiple currencies and querying the API for daily fluctuation data.


The weatherstack API retrieves accurate weather data for any application and use case, from real-time and historical weather information to 14-day weather forecasts.  It also supports all major programming languages.

martketstack API -- stock data, real-time, intraday and historical market data


Delivering stock data, real-time, intraday and historical market data, this REST API has an easy-to-understand request and response structure. Marketstack always sends API requests using a simple API request URL with a series of required and optional HTTP GET parameters. It provides API responses in lightweight JSON format.


The scrapestack API is a simple REST API interface for scraping web pages at scale without having to deal with geolocations, IP blocks or CAPTCHAs programmatically. This API supports a series of features essential to web-scraping, such as JavaScript rendering, custom HTTP headers, various geo-targets, POST/PUT requests and an option to use premium residential proxies instead of datacenter proxies.


The pdflayer API is a quick and seamless way to automate HTML to PDF conversion in any application. Its lightweight RESTful infrastructure combines an efficient combination of the most powerful PDF rendering engines available, making it the most cost-effective and reliable option for anyone looking to process small or large numbers of documents quickly.

The pdflayer API comes with a full set of customisation functionalities, including document configuration, a series of layout adjustment options, authentication and security, design and branding tweaks, and much more.


The serpstack API scrapes Google SERP data in real-time and at scale. Implementation takes just a few minutes using the simple HTTP GET URL structure, and serpstack returns results in JSON or CSV.


With over 15 exchange rate data sources, the exchangerates API delivers exchange rate data for more than 170 world currencies. This API has several endpoints, each of which serves a different purpose or use case.

The endpoints include functionalities like receiving the latest exchange rates information for a specific set, or all currencies; conversion from one to another currency; receiving data Time-series for multiple or one currency; and preserving the API daily for the fluctuation data.

How Can I Supercharge My Web Application?

Because Javascript is an interpreted language, boosting its capabilities with APIs is a quick way to turbocharge your apps. The trick to increasing JavaScript efficiency is to offload tasks to powerful APIs like those from apilayer in this article and bring added functionality right into your browser applications. 

Ready to get started creating super fast and stunning web applications? Click here to get started.