Is MailboxValidator or ZeroBounce cheaper?

MailboxValidator starts at $0 for 300 API queries a month or a 100-query bulk trial, then $19.95 for 1,000 bulk queries (free plan available). ZeroBounce starts at $0 for 100 credits a month, then $39 for 2,000 pay-as-you-go credits or $99 a month for ZeroBounce ONE (free plan available).

MailboxValidator vs ZeroBounce

An independent, review-free comparison compiled by the SaaSTracker editorial team. Both products are profiled in full, and neither can pay for placement here.

The short answer

Editorial assessment

MailboxValidator compared with ZeroBounce

ZeroBounce is the full-suite premium option with SOC 2 Type 2, ISO 27001, HIPAA, its own data centres, EU or US API routing, and warmup and inbox placement tooling, at several times the price. MailboxValidator has none of that and costs a fraction as much. This comparison is really about whether you are buying an audited vendor or a cheap capable tool, and the answer usually depends on whether anyone reviews your suppliers.

Choose MailboxValidator if

Developers and small technical teams who want a cheap, long-lived, no-nonsense validation API with SDKs in their own language, a free tier that never ends, and a flat published price table, and whose lists are B2B or non-Yahoo enough that the provider gap does not matter.

Choose ZeroBounce if

Companies that need one vendor to cover verification and deliverability together, and especially those selling into regulated or procurement-heavy buyers where SOC 2 Type 2, ISO 27001, HIPAA, and a signed DPA with EU routing are requirements rather than nice-to-haves.

Side by side

13 attributes

Attribute	MailboxValidator	ZeroBounce
Category	Verification	Verification
Starting price	$0 for 300 API queries a month or a 100-query bulk trial, then $19.95 for 1,000 bulk queries (free plan available)	$0 for 100 credits a month, then $39 for 2,000 pay-as-you-go credits or $99 a month for ZeroBounce ONE (free plan available)
Pricing model	Two entirely separate products with separate ladders: prepaid bulk plans valid for 30 days with published processing times, and monthly API subscriptions with auto-renewal and auto-recharge including a permanently free tier. No refunds on either.	Two paths that combine: prepaid pay-as-you-go credits on a volume ladder, and the ZeroBounce ONE monthly subscription which bundles credits and deliverability tools and discounts further credit purchases by 15 percent.
Free plan	API-FREE gives 300 queries a month indefinitely with standard support. An invitation-only API-FREE+ plan doubles that to 600.	100 validation credits per month, 10 email finder credits, one inbox placement test, one email server test, and one blacklist monitor. Credits refresh monthly and do not expire.
Free trial	A free bulk trial plan with 100 queries, plus a permanently free API plan with 300 queries per month	No separate trial; the free tier is permanent and refreshes monthly
Best for	Developers and small technical teams who want a cheap, long-lived, no-nonsense validation API with SDKs in their own language, a free tier that never ends, and a flat published price table, and whose lists are B2B or non-Yahoo enough that the provider gap does not matter.	Companies that need one vendor to cover verification and deliverability together, and especially those selling into regulated or procurement-heavy buyers where SOC 2 Type 2, ISO 27001, HIPAA, and a signed DPA with EU routing are requirements rather than nice-to-haves.
Setup time	Minutes for both paths. The free bulk trial needs only an upload, and the free API plan plus a language SDK gets a working integration inside an afternoon. Roughly twenty integrations are positioned as five-minute connections.	Minutes for a list upload or an API key. Connecting an ESP or CRM integration takes an hour at most. Standing up the deliverability suite, meaning placement tests, blacklist monitors, and DMARC ingestion, is a half-day exercise because DNS changes are involved.
Learning curve	Very low technically. The important learning is commercial: understand the 30-day credit expiry, the no-refund policy, and the Yahoo and ASCII limitations before purchase, because all four are the kind of constraint that only hurts after you have paid.	Moderate, and it comes from breadth rather than difficulty. The validation statuses and sub-statuses are richer than most competitors and reward reading the documentation once. The suite tools each carry their own mental model, and teams commonly use two of them and ignore the rest.
Platforms	Web portal for bulk uploads, REST API returning JSON or XML, SDKs for Node.js, Ruby, PHP, Perl, Python, Java, .NET, Go, Rust, Kotlin, and Scala, Platform extensions, Zapier and Make	Web application, REST APIs, iOS app, 200-plus native integrations, Zapier
Compliance	No certifications published, No message sent to recipients during validation, Uploaded lists stated never to be shared	SOC 2 Type 2 (Type 2 since March 2022, audited annually), ISO/IEC 27001:2022 (certified by MSECB), HIPAA SOC 2 Type 2 with BAA available, EU GDPR with internal DPO and EU and UK DPAs, CCPA and CPRA, PCI DSS with monthly third-party assessments, EU-US and Swiss-US Data Privacy Framework participant, EU AI Act readiness documented
Founded	2013	2015
Headquarters	Bayan Baru, Penang, Malaysia	Boca Raton, Florida, United States
Ownership	Privately held and independently operated	Bootstrapped and founder-led; no outside investment

Strengths and limitations

MailboxValidator

Strengths

The widest SDK coverage of any verifier here, with maintained modules for Node.js, Ruby, PHP, Perl, Python, Java, .NET, Go, Rust, Kotlin, and Scala.
A permanently free API plan of 300 queries a month, which is not a trial and makes the service a viable default for a small application.
One of the cheapest published high-volume rates anywhere, at $199.95 for 100,000 and $699.95 for a million addresses.
Around twenty named integrations including Zapier, Make, Mailchimp, HubSpot, SendGrid, Mailjet, Intercom, ChatGPT, and an MCP connector, which is a lot of surface for a very small company.

Limitations

Yahoo addresses cannot be validated at all, which is a serious functional gap on any consumer list and something no competitor profiled here shares.
Non-ASCII addresses are marked as invalid syntax rather than validated, so internationalised addresses are effectively unsupported.
Bulk credits expire 30 days after purchase, by far the shortest expiry in the category, and there are no refunds under any circumstances.
Processing is slow at volume by published admission, up to 72 hours for a million addresses.

ZeroBounce

Strengths

By far the strongest compliance posture in the category: SOC 2 Type 2, ISO/IEC 27001:2022, HIPAA with BAA, PCI DSS, GDPR with an internal DPO, CCPA and CPRA, Data Privacy Framework participation, and documented EU AI Act readiness.
Runs on its own owned data centre hardware rather than public cloud, which eliminates a long list of subprocessor and residency objections before they are raised.
Selectable EU-only or US-only API routing plus 30-day automatic deletion of uploaded files gives a concrete, checkable data-handling story rather than a policy paragraph.
The breadth is real: validation, AI scoring, email finder, activity data, inbox placement, blacklist monitoring, DMARC, server testing, warmup, and a deliverability dashboard from one account.

Limitations

The most expensive per-credit pricing of any self-serve vendor in this comparison set, by a wide margin at every volume below a million.
The pay-as-you-go ladder is punishing at low volume: $0.0195 per address at the 2,000 minimum is more than sixteen times what Reoon charges for a 10,000 pack.
Catch-all addresses are labelled rather than resolved, so the hardest and most valuable part of a B2B list still comes back as a judgement call, mitigated only by a separately billed scoring product.
The free tier at 100 credits a month is an evaluation allowance and cannot support any real cleaning workload.

Pricing compared

MailboxValidator

Two entirely separate products with separate ladders: prepaid bulk plans valid for 30 days with published processing times, and monthly API subscriptions with auto-renewal and auto-recharge including a permanently free tier. No refunds on either.

Bulk trial$0
Bulk plans$19.95 to $699.95
Free API$0
Paid API plans$29.95 to $339.95

MailboxValidator is excellent value for a developer and questionable value for a marketer. The forever-free 300-query API plan, eleven language SDKs, roughly twenty integrations, and a $0.0007 per-address bulk rate at a million are all genuinely strong for a company of a handful of people trading since 2013. But the terms attached to that price are the harshest in the category: credits expire in 30 days, refunds do not exist, and the service cannot validate Yahoo addresses at all or handle non-ASCII ones. On a B2B list processed promptly, none of those matter and the price is superb. On a consumer list bought ahead of a project that slips, you can lose the whole purchase and still have an unvalidated Yahoo segment. Price this as a cheap, capable tool with sharp edges, and only buy credits you are certain you will spend this month.

ZeroBounce

Two paths that combine: prepaid pay-as-you-go credits on a volume ladder, and the ZeroBounce ONE monthly subscription which bundles credits and deliverability tools and discounts further credit purchases by 15 percent.

Freemium$0
Pay as you go$39 to $26,998
ZeroBounce ONE (monthly)$99
ZeroBounce ONE (annual)$948

Priced purely as a verifier, ZeroBounce is the most expensive credible option here: $649 to clean 100,000 addresses against $149 for MillionVerifier and $135 for DeBounce. Priced as a deliverability platform with audited compliance, owned infrastructure, EU routing, and a HIPAA BAA, it is reasonable, because the alternative is a cheap verifier plus a placement testing tool plus a blacklist monitor plus a warmup service plus a security questionnaire nobody can answer. The decision is therefore not about credits at all. If you will use the suite or you need the certifications, ZeroBounce ONE at $79 to $99 a month is defensible. If you want a clean list and nothing else, you are overpaying by a factor of four and should buy elsewhere.

Editorial verdict on each

MailboxValidator

MailboxValidator is a small, honest, long-lived tool that is very good at a specific job and openly bad at several others. Eleven language SDKs, roughly twenty integrations, a permanently free 300-query API plan, and a $0.0007 per-address bulk rate at a million make it one of the best developer-facing options in the category, and the published processing times and openly documented limitations are more candour than most vendors manage. But the limitations are real and unusual: no Yahoo validation at all, no non-ASCII support, credits that expire in 30 days, no refunds, and no catch-all resolution. Those are not deal-breakers for a B2B list processed promptly by a technical team, and they are close to disqualifying for a consumer newsletter or an occasional buyer. Run the provider census on your own list first. If Yahoo is a rounding error and you will spend the credits this month, this is a bargain with excellent tooling. If not, MyEmailVerifier or EmailListVerify does the same work with none of the sharp edges.

Read the full MailboxValidator profile

ZeroBounce

Category Leader

ZeroBounce is the vendor you buy when the purchase has to survive scrutiny. SOC 2 Type 2, ISO/IEC 27001:2022, HIPAA with a BAA, PCI DSS, EU and UK DPAs, selectable EU routing, 30-day deletion, quarterly penetration tests, and its own data centre add up to a posture nothing else in this category approaches, and around that sits a genuinely broad deliverability suite that can retire three or four other subscriptions. The price is the price of all that: at $649 per 100,000 addresses it costs four times MillionVerifier and does not even try to resolve the catch-alls that matter most to outbound teams. Buy it if compliance, breadth, or consolidation is what you are actually solving for, and take ZeroBounce ONE annually at $79 a month so the bundled tools carry their weight. If you simply want a clean list at the lowest defensible cost, this is the wrong end of the market.

Read the full ZeroBounce profile

MailboxValidator profile last reviewed 2026-08-22; ZeroBounce last reviewed 2026-08-22. Pricing is compiled from public sources and can change without notice. See our methodology.