Our team has compiled a list of the most useful and cost-effective Search APIs for your business.

ISBNdb REST API allows you to retrieve information about millions of books.

The ISBNdb database includes over 29 million unique ISBNs with up to 19 data points per book and searchable via our custom API. Choose one of the plans below to access the API for a free 7 day trial.

- Live database with over 29 million unique books
- Up to 19 data points per book including ISBN10, ISBN13, title, author, publication date, publisher, binding, pages, list price, cover image, language, edition, format, synopsys, and dimensions. Other data points for some books are overview, dewey decimal, weight, and subject.
- Searchable by title, author, isbn with multiple endpoint options
- New books and data points added daily
- Multiple languages available
- Used, rare, out of print books and every book in print
- No Long Term Contracts
- Customizable API functionality
- Higher API Requests per second for Premium and Pro Plans
- Bulk Data: get up to 1000 results per call (Premium and Pro only)

ISBNdb API

Ahrefs API is designed to empower our users to use data from Ahrefs Index in the way that suits best to users' needs.

Ahrefs API is designed to empower our users to use data from Ahrefs Index in the way that suits best to users' needs.

Ahrefs take pride in breaking new ground in cutting edge technologies and we've always been striving our best to keep our index fresh. Our own crawler AhrefsBot allows us to visit about 6 billion pages daily, index ~90 billion unique pages with ~700 billion unique external and 4,600 billion unique internal links as of now. And we will continue to build our index better both in size, speed and quality for our users. With the new initiative to build our new Ahrefs API, we're excited about having you from now on to be able to access this data of ours.

Ahrefs API is flexible and can accommodate various needs.
Below are some typical use cases. Read on!

- I want to use backlinks data for my personal needs or for our in-house 
- I want to provide Ahrefs data in my SEO application/service. 
- I want users to connect their Ahrefs accounts to be able to get data.



Ahrefs API

 Global Phone Number Validation & Lookup JSON API

**Global Phone Number Validation & Lookup JSON API**
_Real-time REST API supporting 232 countries_

**numverify API**

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

Requested numbers are processed in real-time, cross-checked with the latest international numbering plan databases and returned in handy JSON format enriched with useful carrier, geographical location and line type data.

Integrating the numverify API into your application will enable you to verify the validity of phone numbers at the point of entry, protecting you from fraud and increasing good leads.

Here are some of the key **features** of NumVerify API:

- **Number Validation**
Capture only good leads, keep your user database clean and fight fraud by validating phone numbers at the point of entry into your system »

- **Simple & Secure API**
Requested using an easy-to-integrate URL structure, delivered in lightweight JSON format, and secured via 256-bit HTTPS encryption »

- **Advanced Tools**
Advanced phone number validation using the most up-to-date international numbering plans, carrier & line type detection, and location lookup »

- **Easy on your Budget**
We're offering the most cost-effective API - validate 250 phone numbers per month for free. Need more? Subscriptions start at $19.99 per month »

NumVerify API

Real-time Geolocation & Reverse IP Lookup REST API

ipapi provides an easy-to-use API interface allowing customers to look various pieces of information IPv4 and IPv6 addresses are associated with. 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.

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

- **Scalable IP lookup trusted by 30,000+ businesses worldwide**
Accurately geolocate users by IPv4 or IPv6 address
Unparalleled in data consistency and response time

- **Powerful & Scalable**
From a thousand requests a month to several million a day — our scalable cloud infrastructure has got you covered at any stage.
 
- **Rock-solid IP data**
Years of data collection and long-term partnerships with large ISPs ensure the highest IP data quality currently on the market.

- **Integrate in minutes**
Powerful and complex on the inside, simple on the outside — our sleek JSON and XML API design will get you up and running in under 10 minutes.

- **Easy on your budget**
IP Geolocation is becoming a global standard. Make 10.000 requests a month for free — need more? Premium plans start at just $10.

ipapi 

Get free access to a database with close to 900,000 foods and over 680,000 unique UPC codes

**Food Database API**
_Get free access to a database with close to 900,000 foods and over 680,000 unique UPC codes_

Food Database API allows you to search for nutrition and diet information within our Food Database.

**Covered Use Cases**

- Search for food by keyword, food name or UPC/Barcode
- Sourcing of nutrition facts for a given food, including: macro and micro nutrients, allergen labels, lifestyle and health labels
- Search for food by given nutrient quantity for 28 nutrients
- Search for foods within a given brand
- With the built-in food-logging context it allows for NLP requests for chatbots and natural language calorie counters

Here are some of the core features of Food Database API:

- **The Food API uses Natural Language Processing and semantically structured data.**
Each search string you input in the API goes through Edamam's proprietary natural language analysis engine. Food entities are found and quantities are attached to them when available.
In Food Logging mode the API allows for development of food logging chatbots. All text is analyzed and quantities of the food are estimated on the fly.
With Edamam's Food Database API you can use the native iOS or Android voice recognition for one click data entry. No more drop downs and search boxes are required.

- **Food database**
Edamam provides access to a food and grocery database with close to 900,000 basic foods, restaurant items and consumer packaged foods
The foods in the Food API can be filtered by Diet and health filters generated by Edamam. All food database data is enriched with diet, allergy and nutrition labeling, as calculated by Edamam based on the food's ingredients. Peanut Free, Shellfish Free, Gluten Free, Vegan, and Vegetarian are some of the 70+ claims generated automatically.
For basic foods from the food database (flour, eggs, flour etc.), Edamam returns data for calories, fats, carbohydrates, protein, cholesterol, sodium, etc. for a total of 28 nutrients. For UPC foods and fast foods data is return as listed on their nutrition label

- **Data Caching**
The terms of use of the Edamam Data are covered in the API Terms of Use and do not permit data caching unless explicitly permitted by Edamam. The data caching described here does not constitute permission to copy or reuse the Edamam data.
Data caching is allowed for some paid API plans when explicitly stated by plan’s terms. API customers can cache only the four basic macro nutrient datapoints - protein, total fat, net carbs and calories as well as the fooId, food label and food image. Saved data can be used only in the end user’s account, behind a password. The caching as described here does not allow API subscribers to build a copy of the Edamam data to be reused in any form or to build a food search. The API still provides full nutrient data which can be displayed on call without caching and customers can only cache the nutrients and data elements described above. Active subscription to an eligible plan is required as long as the data is used

- **UPC or Barcode search**
The Food Database API provides access to over 615,000 unique UPC codes.

- **Low-cost solution**
Edamam provides free Food API access with its basic plan for developers, startups and non-profits alike.
Enterprise customers are charged a very low monthly and per call fee based on usage. Custom packages are also available.



Food Database API

Search over 2.3 million recipes by diets, calories and nutrient ranges

**Recipe Search API Documentation**
_Recipe Search API allows you to search through millions of web recipes and integrate this information into your mobile or web applications._

Here are some of the core **features** of Recipe Search API:

- **Search over 2.3 million recipes in English**
Search our large recipe database. We add new sites and recipes continuously.

- **500+ top web recipe sources**
Our search algorithm returns the most relevant recipes from the most popular and best recipes sources on the web. We order recipes by their cookability and quality, so your customer can always count on getting the best recipes!

- **Semantically organized database**
The recipes in our database are normalized and can be filtered in the search by calorie and diet preferences.

- **Full nutrition for each recipe**
We have the most accurate automated nutrition analysis on the web powered by our proprietary Natural Language Processing (NLP) engine. Customers get detailed nutrition breakdown of each recipe with 25+ nutrients and appropriateness for all major diets.

- **Filter by calories, diet or allergy restrictions**
Edamam has developed over 80 diet and health filters for your customers to use. Now you can develop applications for virtually any popular diet or major health condition.

- **Data Caching**
The terms of use of the Edamam Data are covered in the API Terms of Use and do not permit data caching unless explicitly permitted by Edamam. The data caching described here does not constitute permission to copy or reuse the Edamam data.
Data caching is allowed for some paid API plans when explicitly stated by plan’s terms. API subscribers can cache only the four basic macro nutrient datapoints - protein, total fat, net carbs and calories as well as the recipe URI, recipe title and recipe image. Saved data can be used only in the end user's account, behind a password. The caching as described here does not allow API subscribers to build a copy of the Edamam data to be reused in any form or to build a recipe search. The API still provides full nutrient data which can be displayed on call without caching and API subscribers can only cache the nutrients and data elements described above. Active subscription to an eligible plan is required as long as the data is used.

- **Chronic Conditions Tagging and Filtering**
Edamam offers the ability to search our database of 2.3 million recipes based on their appropriateness to over 200+ chronic conditions. Recipes are ranked for each chronic condition from very beneficial to very detrimental for the specific condition. You can search, for example, for recipes that are good or excellent for a particular condition (e.g., Type 2 Diabetes, kidney disease, hypertension). See a full list of all 200+ chronic conditions covered by Edamam’s service.



Recipe Search API

Scrape Google and other search engines from our fast, easy, and complete API.

**Google Search API**
_Scrape Google and other search engines from our fast, easy, and complete API._

**Advanced Features**
_Leverage our infrastructure (IPs across the globe, full browser cluster, and CAPTCHA solving technology), and exploit our structured SERP data in the way you want._

- **Real Time and Real Results**
Each API request runs immediately – no waiting for results.
In addition, each API request runs in a full browser, and we'll even solve all CAPTCHAs. Mimicking completely what a human will do. This guarantees that you get what users truly see.

- **Accurate Locations**
Get Google results from anywhere in the world with our "location" parameter.
Serp Api uses Google’s geolocated, encrypted params and routes your request through the proxy server nearest to your desired location to ensure accuracy. Get locations at our locations endpoint.

- **JSON Results**
Regular organic results are available as well as Maps, Local, Stories, Shopping, Direct Answer, and Knowledge Graph.
Lots of structured data is available for each result, including links, addresses, tweets, prices, thumbnails, ratings, reviews, rich snippets, and more.

Google Search API

Petfinder's free API is another way we extend your reach to get pets adopted.

**Petfinder is dedicated to helping pets find homes, and we know you are too.** 
_Petfinder's free API is another way we extend your reach to get pets adopted._

The API provides ready access to data for Petfinder's hundreds of thousands of adoptable pets and the organizations that care for them.

- **Shelters and Rescues**
-- Upload your pets on Petfinder.com and display them anywhere, like on your organization's website.
-- Pull your Petfinder listings into your shelter software with the API instead of adding them manually.
- **App Developers**
-- Display adoptable pets from Petfinder in your web or mobile app.
-- Help users find their perfect pets by location, breed, and other characteristics.

Petfinder API

The FoodData Central API provides REST access to FoodData Central (FDC).

The **FoodData Central API** provides REST access to FoodData Central (FDC). It is intended primarily to assist application developers wishing to incorporate nutrient data into their applications or websites.

To take full advantage of the API, developers should familiarize themselves with the database by reading the database documentation available via links on Data Type Documentation. This documentation provides the detailed definitions and descriptions needed to understand the data elements referenced in the API documentation.

NOTE: The API that was available on the USDA Food Composition Databases Web site is no longer being updated and will be discontinued March 31, 2020. Users are encouraged to begin working with the new FoodData Central API system described on this page. This new API allows users to obtain Standard Reference (SR) Legacy data, provides the most current data from the USDA Global Branded Foods Database, and give users the ability to search for specific foods in Foundation Foods and the Food and Nutrient Database for Dietary Studies (FNDDS) 2017-2018.

What's Available
The API provides two endpoints: the Food Search endpoint, which returns foods that match desired search criteria, and the Food Details endpoint, which returns details on a particular food.

**FoodData Central is an integrated data system that provides expanded nutrient profile data and links to related agricultural and experimental research.**

At this time, only a basic view of search results is available for viewing on mobile devices. Advanced filter features, such as searching by data type, are not yet mobile-enabled and are available only in desktop view. Users are encouraged to use a desktop computer to conduct food item searches

FoodData Central takes the analysis, compilation, and presentation of nutrient and food component data to a new level. FoodData Central:

- Can be used by, and has benefits for, a variety of users, including researchers, policy makers, academicians and educators, nutrition and health professionals, product developers, and others.
- Includes five distinct data types that provide information on food and nutrient profiles: Foundation Foods, Food and Nutrient Database for Dietary Studies 2017-2018 (FNDDS 2017-2018), National Nutrient Database for Standard Reference Legacy Release (SR Legacy), USDA Global Branded Food Products Database (Branded Foods), and Experimental Foods. Each of these data types has a unique purpose and unique attributes.
- Links these distinct data types in one location, thus strengthening the ability of researchers, policy makers, and others to address vital issues related to food, nutrition, and diet-health interactions.
- Provides a broad snapshot in time of the nutrients and other components found in a wide variety of foods and food products..

FoodData Central API

Trademark search API allows to search the US trademarks database (USPTO) based on a search string.

**Trademark Search API**
Use  Trademark search API to search the US trademarks database (USPTO) based on a search string. The API allows search by serial number, trademark, owner, upcoming expiration date, and product/service description. Sign up to integrate trademark data into your application.

Our API (application programming interface) is a REST API that searches the US trademark database (USPTO) of wordmarks and returns a JSON-encoded result set of matching trademarks based on a search string.

Marker API V2 has 5 different API endpoints: Serial Number Search, Trademark Search, Description Search, Owner Search, and Expiration Search.

The Serial Number API endpoint returns one record per search and includes all registration data for the trademark.

The Trademark Search API endpoint allows for either exact match or wildcard searching using asterisks for wildcards. The trademark search can return trademarks of all statuses (pending, active, expired) or only active trademarks by setting "status" to "all" or "active".

The Description Search API endpoint searches the goods/services description and performs a wildcard search within the trademark descriptions. The description search can return trademarks of all statuses (pending, active, expired) or only active trademarks by setting "status" to "all" or "active".

The Owner Search API endpoint searches for trademarks registered by a certain person, group, or company.

The Expiration Search API endpoint searches for expiring trademarks within a given, future, time frame ("6 months", "1 year", etc).

All API endpoints implement paging for faster API responses with large result sets with 100 results per page. When a response has more results than what is returned the "next" key is set in the response. The next key is an integer that you should use as your "start" parameter in your next API call to see the next page. You should send all the same parameters (search, status, etc) but change the start parameter for each subsequent page request.

The data returned consists of:
- serial number
- trademark
- goods and services code
- description
- status code
- status
- status description
- owner and address
- filing date
- registration date


Trademark Search API

UPC Database API allows you to access our UPC database with any programming language.

**Welcome to the UPC Database**
_Free information on thousands of products_

**Welcome to UPC Database!**
Since our launch in 2010, we've gathered more than 1.9 million barcode numbers from all around the world. Codes are added to the database from users like you.

Our database contains a mixture of barcode types from the standard UPC numbering system, the worldwide EAN numbering system, and the Bookland numbering system. Our database provides information such as the product name, price, quantity, and manufacturer. We also take this one step further by providing an image of the item, a rating system, and a product alias for shopping list applications.

We offer other services as well such as an API, useful in creating applications, a check digit calculator, a QR Code generator, and now, even a mobile site!

Our mission statement? To provide a platform for members to retrieve and submit product information using our web or API interfaces.

**UPC Database API**
Our API allows you to access our UPC database with any programming language.

We have different API endpoints that you can explore on the left.

When designing our new API, we have taken great steps to ensure the development process remains quick and simple.

- Products
1,960,013

- Images
131,393

- Database size
2,795 MiB

- Monthly API
117,871

UPC Database API

Calendarific is a developer-friendly RESTful API giving you access to public, local & bank holidays and observances; and spanning over 230 countries, 3,300+ states and 100+ languages.

**Worldwide Holidays and Observances RESTful API**
Calendarific is a developer-friendly, worldwide RESTful API giving you access to public, local & bank holidays and observances; and spanning over 230 countries, 3,300+ states and 100+ languages.

Reasons to choose Calendarific Global Holidays API
  
_The impressive list of top Fortune 500 clients we serve all agree,
Calendarific delivers unparalleled holiday data. Just a few other reasons include_

- **Speed**
We use latency based DNS routing to serve over 90% of all requests handled in less than 10ms.
- **Reliability**
Our cloud-based auto-scaling servers can handle over half a billion API queries per day.
- **Up to Date**
Our data is aggregated and verified from multiple sources and updated regularly.

**Covering over 230 Countries, 3300 States, and 100 Languages**
  
Our end-to-end platform offers the most comprehensive holiday and
working dataset of over 200 countries around the world.
Below is the list of countries we currently support.

Calendarific Global Holidays API

High-quality data on over 875,000 grocery products, branded foods, and raw ingredients in the United States, and all around the world.

## Food & Nutrition Database API
High-quality data on over 875,000 grocery products, branded foods, and raw ingredients in the United States, and all around the world.

## Data We Provide
We take pride in being recognized as one of the industry leaders for grocery, branded, and raw food data. Our data is updated on a regular basis and is continually audited to ensure accuracy.

## Tools & Resources
Our API was built by developers, for developers, and follows OpenAPI specifications. We are committed to providing resources, so you get the most out of our database.

## Awards & Accolades
We are extremely proud to be recognized as one of the industry leaders for high-quality food data.

Featured on Product Hunt on February 2, 2020 as the **#3 Product of the Day.**

- API World, a tech conference in Silicon Valley, recognized us as being one of the Top 300 API Industry Innovations.
- Programmable Web recognizes us as one of the Top 7 Nutrition APIs, one of the Top 10 Most Popular Food APIs, and one of the Top 10 Barcode APIs.

Food & Nutrition Database API

BlaBlaCar search API allows to search for carpool trips, just as the BlaBlaCar’s website does. 

### Easily search for trips!
The BlaBlaCar API provides functions for searching and retrieving carpool data. With the API, developers can implement a trip search that displays trips, distance, duration, recommended price, savings, and links. BlaBlaCar API returns JSON data and accepts Key as the authentication method. 

#### Get an API key
In order to access to BlaBlaCar's search API, you first need to ask for an API key [here](https://support.blablacar.com/hc/en-gb/requests/new?ticket_form_id=360000312100).

#### Keep posted
From time to time, we will send planned maintenances, status and important evolutions on this [awesome mailing list](http://eepurl.com/cHubeL). Feel free to register if you want to stay informed.

#### How NOT to use the API?
- As a realtime platform, seats availability may change very often and there might be new trips offered anytime. For this reason, you shouldn't cache the results you retrieve from the API, or for a very small time (10 min max). Also, caching may bypass the "locale" parameter which would result into not the best relevant experience for the user.
- Every query should be triggered by a real user input.
- There is no bulk query so you need to make 1 query for each user's request.

BlaBlaCar API

Use the power of Hunter anywhere through simple API calls. Get started in minutes.

#### Build with Hunter
We believe the most efficient way to distribute a service is to start with an API. The main requests on Hunter can be made using simple API calls integrated wherever you need. Join thousands of growing businesses that have already integrated Hunter’s API to find and verify professional email addresses.

#### Main Functionalities
You can enjoy our service's features with our simple JSON API. Four main calls are available:
- The Domain Search returns all the email addresses found using one given domain name, with sources.
- The Email Finder finds the most likely email address from a domain name, a first name and a last name.
- The Author Finder guesses the most likely email of a person from an article he wrote.
- The Email Verifier checks the deliverability of a given email address, verifies if it has been found in our database, and returns their sources.

#### Resources
Our API also provides you a RESTful way to manage your Hunter's resources. These are the resources you can Create, Read, Update and Delete with our API:
- The Leads
- The Custom Attributes
- The Leads Lists
- The Campaigns

Hunter API

Public API for javascript, css and font libraries on PageCDN.

#### What is the Public CDN API?
Public CDN API consists of endpoints that help you get different kind of information from projects available on PageCDN's Public CDN.

#### Requirements for Public CDN API
You need to have an API key that can be obtained free of cost by creating an account. Paid plans allow you to upload, optimize and accelerate delivery of your private content loaded directly from different sources including but not limited to your website, your Github repos, any public object storage, etc.

Below are the available endpoints on this API:

- Lookup public files
- List files of a project
- List projects and versions

A project (or a repo) can be an open-source library, a theme or a plugin. There are more than 14,000 projects available on Public CDN.

PageCDN Public API

uNoGS (unofficial Netflix online Global Search) allows anyone to search the global Netflix catalog.

### What do we do?
uNoGS scrapes all Netflix Titles everyday in over 30 different countries. 

#### What does the API do?
This API lets you programatically search all the titles on a variety of different parameters letting the user get daily updates on whats new, whats leaving and whats been deleted.

#### Key Features
- Look up specific details for every country
- List and Search titles that have been Deleted
- Get specific Netflix,Country,Season and Episode detail on titles based on Netflix
- Search across entire global Netflix catalog

 uNoGS API

Detect any Browser, Device & OS in Real-Time

Instant, Secure User-Agent String Lookup JSON API trusted by some of the smartest brands worldwide.

#### Powerful & Scalable
From a few hundred API requests a month all the way to several million a day — our scalable cloud infrastructure has got you covered at any stage.

#### Accurate System Data
Backed by a daily updated and constantly monitored User-Agent database, the API delivers the highest level of accuracy & reliability.

#### Seamless Integration
High in complexity and performance, sleek in design — our simple JSON REST API interface will get you started in just a few minutes.

#### Highest Level of Compatibility
No need for a specific set of skills to parse User-Agent data — userstack API functionality can be implemented in under 10 minutes using any major programming languge.

#### Various Use Cases:
- Native App Download
- Tailored Advertising
- Custom Content
- Spambot Detection
- Crawler Protection

The Top 10 Search Apis for Developers