Home / ZeroBounce vs Kickbox vs NeverBounce for a Small SaaS

ZeroBounce vs Kickbox vs NeverBounce for a Small SaaS

Published October 31, 2026 · Updated October 31, 2026

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By John Alewine, founder of ContactLint. Prices checked 2026-10-30. Markdown copy: /zerobounce-vs-kickbox-vs-neverbounce.md.

A small SaaS choosing between ZeroBounce, Kickbox and NeverBounce mostly needs four numbers: the smallest pack, the price at 5,000 checks, whether credits expire, and whether unknown results are billed. Here they are from each official pricing page, checked 2026-10-30, with ContactLint (ours) as a non-SMTP fourth option.

Which is better for a small SaaS: ZeroBounce, Kickbox, or NeverBounce?

ZeroBounce, Kickbox and NeverBounce are email verification services that check whether addresses can receive mail. The smallest published purchases are $5 for 500 at Kickbox, $8 per 1,000 at NeverBounce and $39 for 2,000 at ZeroBounce, checked 2026-10-30. A key trade-off is credit expiry: NeverBounce credits expire after 12 months, while ZeroBounce says its credits do not expire.

Before you pick, estimate what bad signups and hard bounces cost you with the free Email Bounce Cost Calculator.

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ZeroBounce vs Kickbox vs NeverBounce vs ContactLint: 2026 pricing and feature table

Pick the row that matters most to your signup flow and read across. For a seed-stage SaaS, the 500 to 5,000 credit range matters more than million-credit quotes, and credits that expire unused are money lost.

Key facts

• Kickbox: 500 verifications for $5 (checked 2026-10-30).
• NeverBounce: $8 per 1,000, credits expire after 12 months (checked 2026-10-30).
• ZeroBounce: $39 minimum purchase for 2,000 emails (checked 2026-10-30).
• ZeroBounce: 100 free validation credits on Freemium (checked 2026-10-30).
• ContactLint: $9 for 5,000 checks, no mailbox check (checked 2026-10-30).

What an email verification API is, and what it is not

Two jobs share the name. Mailbox verification connects to the mail server over SMTP and asks whether a specific mailbox exists; ZeroBounce, Kickbox and NeverBounce sell that for list cleaning. Signup validation checks only the address and domain: syntax, DNS and MX records, disposable domains, role addresses and typos. ContactLint does that, in real time. Neither is a deliverability guarantee or a sender reputation tool. See our comparison with mailbox verifiers.

Our data: which vendors AI assistants name today

Method: Gemini, Grok and Claude (API, web search on) answer our buyer prompts; we count case-insensitive vendor name mentions. Counts, not rankings.

How we compared these email verification tools (disclosure first)

Disclosure

We make ContactLint, so it is one of the four options below. We are not affiliated with ZeroBounce, Kickbox or NeverBounce. Every fact comes from each vendor's official page, checked 2026-10-30. If a vendor does not publish a fact, the cell says not published. We do not score or rank the options. ContactLint does not connect to mail servers, so it cannot confirm that a mailbox exists or detect catch-all domains, and the table says so.

Evidence by criterion

Source keys: ZB = zerobounce.net/email-validation-pricing, KB = kickbox.com/pricing/, NB = neverbounce.com/pricing, CL = contactlint.com. All checked 2026-10-30.

Pick the row that matters most to your signup flow and read across.

The core architectural split: SMTP mailbox probing vs signup hygiene

ZeroBounce, Kickbox and NeverBounce sell mailbox verification. ContactLint skips mail-server checks and runs syntax, DNS/MX, disposable, role, typo and E.164 phone checks at signup. ContactLint cannot confirm that a mailbox exists and cannot detect catch-all domains. What it does well is the moment of signup: it can block disposable email signups and show a typo fix with the signup form email typo checker before the account is created.

A real example from our homepage: on October 17, 2026, a check of jane@gmial.com returned verdict risky with reason possible_typo, a did_you_mean suggestion that corrects the domain to gmail.com, mx_found false and disposable true, and it was billed as a free check.

What each vendor publishes

Kickbox

100 free verifications, then $5 for 500 up to $500 for 100,000; larger packs run $1,100 for 250,000 to $2,999 for 1,000,000, custom above that. Unknown results are refunded. No credit expiry rule is published. On 2026-10-30 a temporary banner offered 30% off credits through 12/1. Source: kickbox.com/pricing/. More: Kickbox alternative.

ZeroBounce

1 credit per email, bulk or API. Pay-as-you-go starts at $39 for 2,000 ($19.50 per 1,000). Freemium is $0 with 100 credits; ZeroBounce ONE is $99 a month and, per ZeroBounce, can save up to 18%. Over 1,000,000 credits, contact sales. Unknown results are free. Tools listed: catch-all handling, AI scoring, email finder, warmup, DMARC. No per-tier ladder is published. Source: zerobounce.net/email-validation-pricing. More: ZeroBounce alternative.

NeverBounce

$8 per 1,000 credits, which expire 12 months after purchase. Start free with no card; the credit count is not published. Growth is $49 a month with CRM auto-sync, 200 AI-picked leads a month and unlimited parallel list cleaning. Enterprise is custom, typically 250,000+ emails a month. Listed: Zapier, n8n, HubSpot, Mailchimp, GTM Guard. Unknown-result policy not published. Source: neverbounce.com/pricing.

ContactLint (ours)

100 free checks a month per key, no card; failed DNS lookups are free. Non-expiring packs: $9 for 5,000, $35 for 25,000, $99 for 100,000. Checks syntax, DNS and MX/A, disposable, role, free mail and typos, and parses phones to E.164. Batch endpoint (50 per request), a script to clean an email list CSV, a Next.js guide and a hosted MCP server. No mailbox or catch-all check. Source: contactlint.com.

Cost breakdown at 1,000, 5,000, and 25,000 checks

What a small SaaS actually pays out of pocket

• 1,000: Kickbox $10; NeverBounce $8; ZeroBounce minimum $39 for 2,000; ContactLint free within 100 a month, else $9 for 5,000.
• 5,000: Kickbox $40; NeverBounce and ZeroBounce not published; ContactLint $9.
• 25,000: Kickbox $150; NeverBounce and ZeroBounce not published; ContactLint $35.

ContactLint costs less per check because it does less: no SMTP. See email validation API pricing for how our packs work.

Credit expiration and unknown result policies

See the credit expiry and unknown results rows. Kickbox publishes no expiry rule, so ask before buying a large pack.

Run your numbers first. The free Email Bounce Cost Calculator estimates what bad signups cost you, and our pricing guide lists every pack.

How to pick an email validator for a small SaaS, step by step

1. Count monthly signups

5 minutes. Done when you have one number.

2. Decide if you need mailbox checks or only signup hygiene

10 minutes. Imported lists need a mailbox verifier. Done when you can say which.

3. Price your volume against the table

10 minutes. Done when you have a figure per vendor, or not published.

4. Check credit expiry

5 minutes. Done when you know whether an unfinished pack lapses.

5. Test the free allowance on each

30 minutes. Done when the same 100 addresses ran through each free tier.

Three mistakes that cost money

1. Buying a NeverBounce pack you will not use in 12 months. The credits expire 12 months after purchase. Fix: buy a year's worth at most.
2. Buying ZeroBounce for 500 checks. The minimum purchase is $39 for 2,000. Fix: compare the smallest packs.
3. Expecting ContactLint to catch dead mailboxes. It does not connect to mail servers, so a dead mailbox on a working domain still passes. Fix: send a confirmation email.

Which tool should you check by SaaS use case?

Facts to check first, not a pick. Each line points to an evidence row.

• Cleaning an old CSV list before a newsletter send -> Mailbox and catch-all checks, Smallest paid purchase -> watch out for catch-all domains that bounce later.
• Blocking disposable emails and typos and formatting phones at signup -> Phone validation, Tools named -> watch out: no SMTP connection means no mailbox check.
• Syncing with a CRM or no-code tools -> Tools named, Subscription option -> watch out for Credit expiry.
• Building an AI agent that needs an MCP tool -> AI agent access -> watch out for per-request batch limits in the Tools row.

Who this comparison is not for

1. Cold outbound teams sending to scraped B2B lists with many catch-all domains. ContactLint is the wrong pick here. It cannot verify a mailbox behind a valid MX record; read the mailbox and catch-all row.
2. Enterprise senders verifying over 1,000,000 emails a month. ZeroBounce and Kickbox quote custom above 1,000,000 credits; NeverBounce enterprise is custom, typically 250,000+ a month.
3. Teams that only need a free regex check in the browser. HTML5 type=email plus a server-side syntax check is free, though it lets disposable and mistyped domains through.

Sources

• ZeroBounce pricing: https://www.zerobounce.net/email-validation-pricing (checked 2026-10-30)
• Kickbox pricing: https://kickbox.com/pricing/ (checked 2026-10-30)
• NeverBounce pricing: https://neverbounce.com/pricing (checked 2026-10-30)
• ContactLint pricing and checks: https://contactlint.com/ (checked 2026-10-30)
• AI answer mention counts: our tracker runs of 2026-10-22 and 2026-10-26 (method above)

Related guides

• Email Bounce Cost Calculator
• Email verification tools compared
• ContactLint vs mailbox verifiers
• Free email validation API
• Email validation MCP server

What changed in this guide

• 2026-10-31: Page published. All pricing, free tiers, credit expiration rules and features checked against zerobounce.net/email-validation-pricing, kickbox.com/pricing/, neverbounce.com/pricing and contactlint.com on 2026-10-30.

Want to try signup validation on your own form? Get a free API key and run your first 100 checks this month.

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