Updated: April 11, 2025
APIs are incredibly helpful tools. They can be an easy way to give your website some life, provide nifty functionality for your users, or can even just help your brand look really cool. Thanks to developers around the globe, there’s an API for almost everything you can think of -- and the majority of them are easy to integrate.
With this list, we’ll break down the topic into a couple of sections (as the APIs that will be useful for specifically B2B aren’t always going to have much to offer for a wider audience), as well as breaking down some of the more widely useful APIs that can provide you some real benefits no matter what you’re offering.
An API, or Application Programming Interface, is almost like a shipping port for websites. You can send requests (in this analogy, they’d be ships) to the port, and they’ll either drop some cargo off and come back with an “A-Okay!” message, or they’ll pick something up at the port and come back to you.
In recent decades, as things on the web have gotten a bit more user-friendly (even for devs!), it seems as though “Application Programming Interface” seems like an intimidating and overly complex way to describe how simple and easy-to-use a lot of the more popular APIs really are.
Among the most popular APIs out there is the Google Maps API, something we’ve all definitely interacted with at one point or another, whether it’s because you’re trying to track down a business address from their website, or figuring out nearby parking when you’re headed in for a meeting.
There are a couple of different types of API that you’ll be running into online nowadays, and it’s helpful to be aware of them:
Sadly getting less and less common as web traffic increases and server costs follow it upwards, the public API is part of what built and fueled the creativity and innovation of the early internet. In fact, the Google Maps API used to be a public API, easily accessible without giving up your billing information.
Public APIs are typically free, but can still require that you generate keys to authorise against them.
This is the more common type of API you’re going to be making use of. In light of the rise of SaaS (Software as a Service), you can now find near-endless amounts of companies with proprietary APIs that you can interact with for a fee.
These generally do require authorisation and keys - probably a good thing, given that you’re paying for the access!
So, moving on - let’s get into the juicy bits!
In this section, I’ll be looking at the most helpful APIs for your site - no matter what your specific niche, market, or product offering is. These will be a mixture of free and paid APIs, but I’ll let you know about any paywalls associated with each API as we’re looking at them.
Obviously, this is my number one. No matter what your business offers, it’s always beyond helpful to have a Google Maps integration on your site so that potential customers, hopeful job applicants, or anybody needing to visit your offices can figure out exactly where you are without having to leave your site.
There’s also a couple of bonuses and related APIs to the Google Maps API that I don’t see getting as much love as they really should. The Google Maps Geocoding API is a fantastic tool, that shares a lot of space with the regular Maps API but is a sort of beefed-up version. Particularly handy for those situations where you need to accept a postcode or address and then return a list of your closest offices or retail spaces, ordered by distance - this tool is an absolute must for anything that requires distance calculations and takes user input.
A second, super cool aspect of the Maps API is just the sheer number of settings you’re able to tweak. These settings can be more mundane things like how zoomed-in the map is on load, but can be much more visual - you can customise the colours of almost everything, and determine whether you want to show or hide certain elements depending on what you want. This means your map doesn’t have to rep the Google brand colours; you can customise it to match your brand.
The Maps API has started to charge users, as part of the Google Cloud Platform. It does come with $200 of free monthly credit, which will probably cover all of the bills of your integration unless you’re getting huge amounts of traffic.
If you’ve got an audience, you need to be reaching them. As long as you’re following GDPR and respecting their privacy and space, you can definitely run hugely successful marketing campaigns via direct mail to their inboxes -- and an API integration with Mailchimp is the way to go.
There are, of course, plenty of alternative cold email software, but with (in 2019) over 4 million customers, Mailchimp is a monolith of the campaign world - and apparently, their customers have reached over 4 billion people.
The Mailchimp API allows for easy customer signups, and surprisingly in-depth backend tools to make sure that you know where those signups came from on your site, and feed them through to the appropriate lists.
If you’re taking payments online, you’re going to need a payment gateway. PayPal has been around for years, and Stripe isn’t an up-and-coming brand either, having firmly established itself in the online space.
Payment APIs are, as to be expected, a little more complicated than your typical integration, but are arguably the most important integration for any business that’s serious about making money online. They take a lot of tweaking and technical fiddling, but once they’re set up you can broaden your selling channels to include anybody with an internet connection - as long as you can get the products shipped out to them!
So, now that we’ve taken a quick look at some of the most helpful APIs for any kind of B2B site to have, let’s break it down into specific niches and uncover some of the APIs that will help you get ahead in your market.
If you’re looking for market research, look no further. This API has an endpoint that allows you to find “Lookalike” companies, meaning that you can expand your audience by using your pre-existing clients to find similar business opportunities.
The way that this works is that you enter a URL of a company website, or the URL of their LinkedIn page, and the Market Intelligence API scans all of their messaging and content and searches for companies with similar messaging.
This means you can find potential new clients - or you could use it to keep tabs on your competitors and figure out who your competition is and how they’re getting ahead.
However, you can also search by directly inputting keywords - which is super handy if you’re brainstorming and potentially breaking into a new market or a new audience and don’t know the best company to use for results, or don’t want your results polluted with content and keywords that you’re not looking to target.
There are a few paid tiers to this service, but there is also a paid service that allows you to use up to 50 API calls per month (at the time of writing).
If you’re selling B2B, you know how important it is to skip the gatekeepers on the phone lines and get around the support desks that reply to most of the email addresses you’ll find online, and get your product in front of a decision-maker immediately. It can be tricky to get access to higher-level executives who hold sway, but that’s where UpLead comes in.
The Prospector API allows you to search a person’s name or email address and get back detailed and full information that will help you to get in touch with them, or fetch crucial contact info about them. Definitely handy for getting noticed, and picking up new clients!
Prospector also comes in useful when you’re trying to get the lowdown on company info, as opposed to people. They boast 30+ attributes for any company, which include location, size, and contact info - handy for figuring out if they’d make a good client, or for staying informed about who you’re going up against.
One of the things that makes this API really unique though is that they put their money where their mouth is; they don’t charge you per request, the way a lot of other APIs (including Google) do. They charge you for results, charging 1 “credit” for each result. This means that you can rest easy querying for those lesser-known or smaller companies, safe in the knowledge that you’re not throwing money at the wall
Let’s face it: contracts are boring. Essential, definitely - but boring. Signable is among a range of SaaS that’s intended to eliminate the busywork and the waiting involved with physical, paper contracts, and signatures.
The Signable API allows for all kinds of handy automation, integrating with your CRM of choice to send out documents and contracts instantly when the time comes, and accepting signatures over the internet.
It has some pretty big-name clients - like Krispy Kreme, BMW, The Body Shop, and even beloved Bristol locals Aardman studios.
There’s no free tier to Signable, however, there are plenty of pricing tiers to choose from to meet your budget needs.
LinkedIn is the Facebook of B2B. Obviously; you already knew that - you’re in B2B, you’re all over LinkedIn already. But are you making the most of that social media platform? You could integrate it into your website via their API and allow for direct connections to your staff, for instance, or allow for your blog articles (which you should definitely be keeping up to date with, by the way) to be shared.
But there’s so much more to the LinkedIn API. The LinkedIn Marketing Developer Platform is a collection of smaller APIs and endpoints that open up a lot of marketing capabilities when it comes to getting your name out on LinkedIn. It can help you manage your advertising (and ad spend), as well as handling campaigns, and guide you in the right direction to raising your brand awareness and generating leads that will really interact with your business.
There’s also the Sales Navigator Analytics platform, which helps you to drive sales through LinkedIn by giving you the opportunity to review and analyse your sales data, using that to develop effective strategies to get more clients and bring in more revenue.
All in all, APIs are an incredibly handy part of the internet. There is an almost unlimited number of APIs, offering all kinds of functionality, from the crucial payment gateways, to the helpful Google Maps API, to APIs that help connect you directly with your clients via direct marketing, social channels, or through analysis of your previous interactions to help guide your strategies in future.
There are a surprising amount of APIs available for free, which is an absolute testament to how the internet has grown through sharing, open-source ideals, and an innovative and exciting attitude, as well as a curiosity that drove people when there was no profit motive to be had.
In conclusion, these are the most useful general and business-to-business APIs to use in your projects. We hope that they are useful to you and your business. We'd recommend checking out the documentation and creating a plan for implementation.
These can help save you a great deal of time, rather than creating all of this functionality from scratch.
All in all, it can help save days or even weeks of time.
Please check each company's documentation and setup guide to get an idea of how long it will take you to implement each one.
Happy building!
Last updated: April 17, 2021