Comparison

NeverBounce vs Kickbox

Two developer-focused email verifiers with different result models. Every fact below comes from the vendor’s own pricing page, API reference or official code libraries, with the date we checked it.

Updated October 11, 2026 · 5 min read

NeverBounce vs Kickbox is a choice between two verifiers that both serve developers well but report results differently. Kickbox gives every address a verdict, a reason and a Sendex quality score; NeverBounce gives a result code plus a long list of flags, and adds integrations and AI lead scoring on its Growth plan. This comparison uses each vendor’s own pages, checked October 10–11, 2026.

Disclosure: we make emailvalidation.io, a third verifier covered briefly at the end. Both vendors’ strengths are listed in their own sections, and the sources are at the end.

Quick verdict

Choose NeverBounce for no-code connections (80+ integrations, CRM auto-sync on Growth), a documented form widget, a free sample run on a list, and wrappers in seven languages.
Choose Kickbox if you want one verdict per address with a reason and a quality score (Sendex) you can threshold on, and a timeout you set per request.
On price, the two are level at 5,000 checks ($40 each); from 10,000 checks NeverBounce costs less, with 100,000 credits for $400 against $500 at Kickbox.

NeverBounce vs Kickbox pricing

Row label	NeverBounce	Kickbox
5,000 checks	$40 (credits)	$40 (credits)
10,000 checks	$50 (credits), or Growth at $49 / month	$70 (credits)
25,000 checks	$125 (credits)	$150 (credits)
100,000 checks	$400 (credits), or Growth at $159 / month	$500 (credits)
1 million checks	$2,500 (credits); Enterprise custom, “typically used for 250,000+ emails per month”	$2,999 (credits); custom pricing above 1 million
Free tier	Free test credits and a free first list analysis	100 free verifications
Credit expiry	12 months after purchase	Not stated on the pricing page
Not charged	Duplicates (Growth plan); a sample run on a list	Unknown results (credit refunded)

Features compared

Row label	NeverBounce	Kickbox
Real-time API	`GET /v4.2/single/check`	`verify` call in each official library
Timeout	Optional, in seconds	Optional, in milliseconds (default 6,000)
Result	`valid`, `invalid`, `disposable`, `catchall`, `unknown`	`deliverable`, `undeliverable`, `risky`, `unknown`, plus `reason`
Catch-all	`catchall` result plus `accepts_all` flag	`accept_all` flag
Quality score	–	`sendex`, 0 to 1
Other data	22 flags (role account, free host, spam trap network and more); typo suggestions	`role`, `free`, `disposable`, `did_you_mean`
Credit balance in responses	Optional `credits_info`	`X-Kickbox-Balance` header on every response
Bulk	Jobs API: supplied data or remote file, 25 MB per request, callback URL; free `run_sample`	Batch API: up to 1 million addresses per request, optional callback URL; list upload in the app
Libraries	PHP, Ruby, Node.js, Python, Go, .NET, Java; JavaScript widget	PHP, Node.js, Ruby, Python
Integrations	80+ (Zapier, n8n, HubSpot, Mailchimp and more)	28 listed (HubSpot, Mailchimp, Klaviyo, Salesforce, Zapier and more)
Beyond verification	Growth: 200 AI-selected leads a month, AI scoring, CRM auto-sync	Verification and support based in the US and the EU

Where NeverBounce is stronger

Integrations and auto-sync. More than 80 integrations, and CRM auto-sync on the Growth plan checks new contacts without uploads.
Bulk you can try first. The jobs API can run a sample on a list and estimate its bounce rate “without costing you” before you start the full job.
More languages and a form widget. Wrappers for seven languages and a JavaScript widget with events for results and form submits.
Finer detail through flags. 22 flags cover government, academic and military hosts, spam trap networks, aliases and more.
Lower prices from 10,000 checks. 10,000 credits cost $50 against $70 at Kickbox, and 100,000 cost $400 against $500. The Growth plan covers up to 100,000 a month for $159.

Where Kickbox is stronger

A single verdict with a reason. deliverable, undeliverable, risky or unknown, each with a reason such as rejected_email or invalid_domain, maps cleanly onto code paths.
The Sendex score. A 0–1 quality score on every check lets you set your own threshold instead of trusting a label.
Catch-all as a flag, not a result. accept_all sits next to the verdict, so a catch-all address can still be scored and classified.
Millisecond timeouts. Each library takes a timeout in milliseconds (default 6,000), handy on sign-up forms.
Unknown results refunded. When Kickbox can’t give a definitive result, it refunds the credit.
US and EU processing. Kickbox says verification and support are based in both the US and the EU.
Balance in every response. The X-Kickbox-Balance header shows your remaining credits (daily plus on demand), so you can alert before you run out.

A third option: emailvalidation.io

If you only need verification at a steady monthly volume, here is what we offer, from our own email validation API pricing page:

Row label	emailvalidation.io
5,000 checks	$9.99 / month (Small)
25,000 checks	$34.99 / month (Medium)
100,000 checks	$94.99 / month (Large)
Free tier	100 checks a month, 10 requests a minute
Result	`state` (`deliverable`, `undeliverable`, `unknown`), `reason`, `score` 0–1
Catch-all	`deliverable` with reason `low_deliverability`; `catch_all` field with `catch_all=1` (Small plan and up)
Bulk	Up to 100,000 addresses per job, JSON or CSV/TXT, one signed webhook on completion
Integrations	Zapier integration, MCP server, SDKs for JavaScript, Python and PHP

Our response is close to Kickbox’s in shape (state, reason, score, role, free, disposable, did_you_mean). Only successful calls count; in bulk jobs, duplicates and invalid rows are free and timeouts are refunded when the job finishes. Large lists can take a day or longer, because checks are paced per receiving mail server. We have fewer integrations than NeverBounce and no form widget. See the email validation API page for a full response and the bulk email verifier to try a few addresses in the browser.

More comparisons: Kickbox alternatives, NeverBounce alternatives, NeverBounce vs ZeroBounce and the best email verification tools.

Sources

Checked October 10, 2026: NeverBounce pricing (pay as you go, Growth, Enterprise, free credits, expiry, integrations); NeverBounce single check (results, flags, wrappers, widget) and jobs create (input, size limit, sample, callback); Kickbox Node.js library and Kickbox Python library (response fields, timeout, balance header, free account); Kickbox on GitHub (official libraries); emailvalidation.io pricing. Checked October 11, 2026: NeverBounce pricing (pay-as-you-go volumes, Growth tiers); Kickbox pricing (price list, free verifications, unknown refunds, US and EU); Kickbox batch verification API (batch size, callback); Kickbox integrations.

Frequently asked questions

Is Kickbox or NeverBounce cheaper?

NeverBounce, at most volumes (checked October 2026). Both charge $40 for 5,000 checks; 10,000 cost $50 in NeverBounce credits against $70 at Kickbox, and 100,000 cost $400 against $500. NeverBounce credits expire 12 months after purchase, while Kickbox refunds unknown results.

What is the difference between Kickbox and NeverBounce results?

Kickbox returns deliverable, undeliverable, risky or unknown, plus a reason, an accept_all flag and a Sendex score from 0 to 1. NeverBounce returns valid, invalid, disposable, catchall or unknown, plus up to 22 flags.

Do NeverBounce credits expire?

Yes. NeverBounce’s pricing page says credits expire 12 months after purchase.

Does Kickbox or NeverBounce have a free plan?

Kickbox’s pricing page lists 100 free verifications, and its libraries point you to a free account for an API key. NeverBounce offers free test credits and a free first list analysis, without saying how many credits.

Email validation API

Validate emails in your app

emailvalidation.io checks syntax, MX records and the mailbox over SMTP, flags disposable, role and free addresses and returns a quality score, in one request.

/v1/info Email validation API Read the documentation

100 free validations every month. No credit card required.

GET https://api.emailvalidation.io/v1/info?email=support@emailvalidation.io

{
  "email": "support@emailvalidation.io",
  "user": "support",
  "tag": "",
  "domain": "emailvalidation.io",
  "format_valid": true,
  "mx_found": true,
  "smtp_check": true,
  "catch_all": null,
  "role": true,
  "disposable": false,
  "free": false,
  "score": 0.64,
  "state": "deliverable",
  "reason": "valid_mailbox",
  "did_you_mean": ""
}

Keep reading

NeverBounce vs ZeroBouncePrices from 1,000 to 100,000 checks, free tiers, credit expiry, result types, bulk jobs and deliverability tools, side by side. Kickbox alternativesKickbox’s credit prices and result model next to monthly plans and other credit packs, with a field-by-field migration table. NeverBounce alternativesPublished prices for 5,000, 25,000 and 100,000 checks, free tiers, credit expiry, API, bulk and integrations, side by side. Best email verification toolsThe best email verification tools of 2026 compared on published facts: price per 10,000 checks, free tiers, API, bulk upload, catch-all handling, integrations. Email validation APIChecks the syntax, MX records, SMTP mailbox and disposable or free-provider status of any address in real time, as JSON. Email validation API pricing100 free checks a month, paid plans from $9.99 for 5,000. Monthly or yearly, cancel anytime.

Start using our email validation software today!

Get 100 validations per month for free