Zerobounce API – The Email Marketer’s Review

Mar 12, 2024

Even if we wanted to, we can’t overstate the importance of maintaining clean and responsive email lists. To enjoy such lists, various companies provide us with their solutions.

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Among them is ZeroBounce and their email validation API, which is designed to elevate email marketing.

Grab a cup of coffee and sit down for our overview of this ZeroBounce service, as we’ll touch on a lot of areas today, including how the API works, documentation, speed, user satisfaction, etc.

What is the ZeroBounce API?

The ZeroBounce API (Application Programming Interface) is a tool that allows you to verify email addresses using ZeroBounce’s capabilities externally, for example on your favorite apps and platforms. It’s fast, secure, accurate, and gives real-time results. 

ZeroBounce API helps marketers ensure the health and efficiency of email marketing campaigns by meticulously checking if an email address is valid, operational, and capable of receiving messages. It can identify different types of problematic emails in real time. 

Once it determines, for example, disposable emails, high-risk emails, and other invalid contacts, it prevents them from entering your email list. As a result, you should only deliver messages to valid addresses.

Implementing the ZeroBounce API into your email validation process offers further advantages:

  • Thanks to it, marketers can reduce email bounces, which happen when sent emails fail to reach their intended recipients. 
  • The API aids in identifying and filtering email addresses associated with abuse or other malicious activities and won’t miss spam traps.
  • It can improve engagement rates and communication with your audience. 

So, in general: ZeroBounce API does pretty well, and users are usually satisfied with its performance.

Zerobounce API - review


The added advantage of the API is that it makes it easy to connect ZeroBounce to your website or app. Your developers won’t have to worry about writing complex code as the API is fairly easy to connect to existing frameworks.

How does ZeroBounce API work and how do you get started?

When someone enters an email address on your website or in your app, the API quickly checks it against several validation criteria to determine its validity. 

This process includes checking for email formatting errors, domain validity, and whether the email address is disposable, or belongs to an inactive account. 

Also, the API can detect and flag abuse emails or accounts likely to mark emails as spam, and provides a sub-status code to help explain some of the unknown and invalid outcomes. 

The final result is a detailed report on each email address, indicating whether it’s safe to use in marketing campaigns or should be removed from the list.

In short, the ZeroBounce API works by taking an email address you provide, scanning it against various criteria, and then returning detailed information about its status. 

Here are 3 steps to get started:

  1. Create a ZeroBounce account. The free account lets you validate 100 monthly emails and 10 Email Finder queries. 
  2. Next, you must get an API key – you can generate up to 5 of them. 
  3. Then, connect your apps using information from their API documentation.

The documentation says that a quick start of the API is possible with Postman Collection. You should save the Postman Collection contents as a .json file or get the file from the ZeroBounce GitHub repository. 

In Postman, on the top menu, click on File, then choose Import. Then, choose the JSON file you saved or downloaded from GitHub to import it. You can activate the API by installing it on your signup or registration forms, or wherever you collect email addresses online.

Thanks to this process, you should get detailed insights into email address validation status and deliverability potential, and improve the email marketing ROI.

The API documentation

The ZeroBounce API documentation is fairly good and allows anyone to do more than just set up the API. 

In addition to information on how to connect with Postman, it provides insights about authentication instructions, endpoint descriptions, and examples. Also, it explains how to get credit balance and tells about API usage, single email-validator in real-time, allowlist and blocklist, sandbox mode, status code, v2 changes, file management, support, and community, etc.

The ZeroBounce API documentation is quite comprehensive and user-friendly, and it’s designed to assist developers in integrating and using the API effectively.

The API accuracy for email validation

ZeroBounce claims it has the world’s most accurate email verifier API, and its accuracy is at a 99% rate – which is a strong statement in the email verification field. However, when digging into various sources and reviews, you can find various opinions that say the rate is lower – at around 98%. 

What’s more, while ZeroBounce API is highly regarded for its capabilities, the APIs of competitors, like Bouncer, may be better in this regard. For instance, Bouncer is more accurate than ZeroBounce, as it has 99.5%

Although seemingly small, this discrepancy can be significant depending on the volume of emails verified. For large email lists, even a 1-2% difference in API accuracy can impact the effectiveness of email marketing campaigns. This case could lead to higher-than-expected bounce rates and affect the sender’s reputation.

There is also a noted difference in actual bounce rates: with Bouncer, you can expect a 5% bounce rate, and with ZeroBounce, as much as 8-9% when sending a campaign.

The consensus is that while the tools’s API is powerful and with a wide range of features and benefits, users should be mindful of the claims of 99% accuracy. The reality is that in the nuanced domain of email verification, absolute accuracy can vary, and small percentages can indeed make a huge difference. 

Especially for businesses relying on email communication for marketing, outreach, and customer engagement.

The ease of use

ZeroBounce API and the whole tool are generally considered easy to use by its customers, with many praising its user interface, navigation, documentation, and the simplicity of its email validation process. 

Here are some examples of what their customers have said:

Users appreciate the ease of use and efficiency of ZeroBounce’s API. They found the platform “undoubtedly easy to use” and praised its variety of benefits and features that make the tool invaluable.

Zerobounce API - review


On the other hand, not everyone finds the platform convenient. Some customers emphasize, for example, the difficulty of using cleaned files. However, such reviews are rare.

Zerobounce API - review


While some appreciate the ease of use, they still highlight areas that negatively affect the overall user experience. For example, time validation is sometimes too slow. This can be seen as a minor annoyance but nevertheless, it creates problems.


The verification speed

ZeroBounce claims their email verification API is rapid, almost instant. Clients can validate a single email address in just 3 seconds, and clean their entire list in under 1 hour.

Moreover, the batch API endpoint allows users to batch up to 200 emails for cleaning simultaneously. It can run up to 5 uses per minute and give results up to 70 seconds for each email address. If the speed limit is surpassed, the user will be blocked for 10 minutes.

Also, in the documentation, we can read that the response time for their API is between one second and 30 seconds. ZeroBounce limits the amount of time they spend validating an email address, thus, if the tool encounters a slow mail server or a mail server with a greylisting algorithm, you will get an unknown result. However, approximately 96-98% of all domains will return within about 5 seconds.

Customer feedback is optimistic about the speed of the tool, but there are cases where it doesn’t work quickly, such as with extensive mailing lists and the server load.

The better alternative to the ZeroBounce API

If you want to validate emails like a pro and not worry whether the API you are using is actually effective, you might also consider the email verification API from Bouncer. 

Why is Bouncer a quality and better alternative to ZeroBounce API?

Bouncer API - homepage
Bouncer email verification API stands out in the realm of email verification for its remarkable features that cater to developers and marketers alike. 

At the heart of its offering is a promise of exceptional accuracy, boasting a 99.5%+ rate in validating email addresses. 

This level of precision keeps your email list clean and efficient and makes sure that communications reach your intended recipients without the hindrance of bounces or a spam trap.

Ease of use is another cornerstone of Bouncer’s service. The API is designed to be straightforward, allowing for seamless integration into existing systems. 

This user-friendly approach extends to its documentation, which is thorough and clear, and contains many examples. It makes it easier for developers and marketers to implement and utilize the full capabilities of the API without unnecessary complexity.

Bouncer API - review


Premium support is a highlight. You have a dedicated support team member at your disposal. You can speak with them via video call, chat, and email. 

With such a dedication to customer service, you are sure that any queries related to the API’s use or integration are swiftly addressed.

Another field where Bouncer shines is speed. Time is of the essence in email verification, and Bouncer excels here, as it offers great speed in processing requests. 

You can verify up to 500,000 emails at a rate of 100,000 emails per hour. All this is done in a secure environment. As you can see, even large volumes of email addresses can be verified quickly.

Above that, Bouncer’s pricing structure is simple and transparent (and cheaper than ZeroBounce’s.) This straightforward pricing guarantees businesses of all sizes can access high-quality verification services without worrying about complex cost calculations.

But Bouncer offers far more. It provides tools such as Toxicity Check, Deliverability Kit, Email Verification, and many integrations. This allows you to clean lists, catch all email addresses, block invalid ones, test inbox placements, assess IP address reputation, and much more to protect your email deliverability.

This all makes Bouncer’s API an indispensable tool.


Bouncer CTA

Use the best email validation API and improve experiences

ZeroBounce API is a valuable tool for any organization looking to optimize its email marketing strategies. It helps maintain a clean and efficient email list and contributes to the overall success of your email-based communications. 

However, it isn’t a perfect solution.

Bouncer can meet your requirements better because it outperforms ZeroBounce in many areas, as you just saw in this article. 

Although there is no tool that will provide you with 100% accurate results in the blink of an eye, you can at least look for one that approaches perfection. That’s the reason for checking out Bouncer.

Make the best decision for your business and contact us anytime.

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