Bouncer

1. 1

   You upload a list to the web app, connect an integration, or call the verification API. Bouncer runs its checks and returns one of three plain verdicts: deliverable, meaning safe to send; undeliverable, meaning a bounce; or unknown, meaning it could not reach a confident conclusion and refuses to guess.

2. 2

   The unknown bucket is the design decision. Bouncer targets roughly 98 percent coverage, so about 2 percent of a list is left unresolved, usually because of temporary misconfiguration, provider oddities, or genuine ambiguity. Those rows are not charged. Neither are duplicates, which the system removes before billing.

3. 3

   The guarantee sits behind the deliverable verdict. Bouncer claims over 99 percent accuracy overall and 100 percent accuracy on undeliverables, and it commits to refunding contacts marked deliverable that bounce within 72 hours of verification for an objective reason. That is a narrower and more testable promise than a generic accuracy percentage.

4. 4

   For ongoing use, Bouncer Shield validates addresses at the moment someone types them into a form, AutoClean re-verifies a connected CRM continuously, and the Deliverability Kit runs inbox placement tests, authentication checks, and blocklist monitoring as a separate monthly subscription. Toxicity Check and Data Enrichment run as extra passes over an already verified list.

Prepaid verification credits on a fully published volume ladder with no expiry, plus two separately priced subscriptions: Bouncer Shield for real-time checks and the Deliverability Kit for placement and monitoring.

Value assessment: Bouncer sits deliberately in the middle and mostly earns it. At $400 per 100,000 addresses it costs about a third of ZeroBounce and roughly two and a half times MillionVerifier, and what it buys with that premium over the budget tier is a published guarantee with a specific remedy, EU-only hashed storage with 60-day deletion, and a $1,000-per-million rate at scale that stays competitive. The entry point matters too: a 1,000-credit minimum at $8 is the cheapest way in the category to genuinely test a vendor on real data. Where the value slips is the unbundling. Shield and the Deliverability Kit are separate subscriptions, so the fully-equipped version of Bouncer is not the mid-market bargain the credit table suggests.

Setup time

Under fifteen minutes. Sign up, take the 100 free credits, upload a list or copy an API key. Bouncer Shield needs a snippet on the form and AutoClean needs a CRM connection, each an hour at most.

Learning curve

Low. Three verdicts instead of a status taxonomy makes the output immediately usable, and the unknown bucket is explained rather than treated as an embarrassment. Toxicity scores take a little longer to internalise because the one-to-five scale is a risk gradient rather than a pass or fail.

Onboarding

Fully self-serve at every published volume, with a 1,000-credit minimum that makes a real trial affordable. Enterprise and deliverability consulting engagements exist for larger deployments but are not required to buy or use the product.

Migration notes

Expect a larger unknown bucket than your previous vendor produced, and read that as the design working rather than as a coverage failure. Because unknowns and duplicates are not billed, the shift usually costs less than the raw volume suggests. If the reason for switching is European data residency, note that the entire platform is EU-hosted rather than offering an EU option, so there is no endpoint to configure.

Platforms

Web applicationREST APIBouncer Shield form widgetAutoClean CRM connectorNative integrations

API

Documented email verification API for single and batch checks, marketed for engineers as ultrafast and easy to integrate, drawing on the same credit balance as the web app. A public status page is published.

Compliance

GDPR by design with a published data processing agreementEU-only data storage

Data residency

Data is stored only in EU AWS data centres. The company is headquartered in Wroclaw, Poland and states it hosts exclusively in the EU.

SSO

Not published as a standard plan feature.

Security notes

Uploaded email addresses are hashed and anonymised in all parts of the system except the layer from which results are downloaded. Verification results are erased after 60 days automatically, and users can permanently delete results on demand at any time. A data processing agreement and privacy policy are published, and the company writes publicly about SOC 2 in the context of email validation, though the public site's compliance evidence is centred on GDPR and EU hosting rather than a downloadable certification pack.

Channels

Live chatEmailVideo callPostal mail, seriously offered on the GDPR page

Documentation

Public documentation covering the app, API, Shield, and AutoClean, plus a status page, FAQ, and a knowledge hub.

Community

No user forum. There is an agency partner programme, an ambassador scheme, webinars, case studies, and an unusually active blog.

Founded

2017

Headquarters

Wroclaw, Poland

Ownership

Privately held, seed-stage venture backing reported

Founders

Radek Kaczynski

Employees

Small team, in the low tens (public estimates, 2026)

Funding

Reported as a seed-stage company; no large funding rounds are publicly disclosed.

Bouncer is the most thoughtfully positioned verifier in this set. Its stated bias against false negatives, its 100 percent undeliverable accuracy claim, and its 72-hour bounce refund make a promise that can actually be tested, which is more than most accuracy percentages in this category amount to. The European data posture, hashed storage, EU-only AWS hosting, 60-day deletion, and a published DPA, is concrete rather than performative, and the fully published price ladder with non-expiring credits and no billing for duplicates or unknowns is exactly the transparency the category usually avoids. The costs are real too: $400 per 100,000 is well above the budget tier, the deliberate unknown bucket leaves catch-all-heavy lists partly unresolved, and Shield and the Deliverability Kit are separate subscriptions that quietly undo the mid-market pricing. For a European small business that wants to buy verification once, understand the bill, and never lose a live contact to a wrong verdict, this is the right default.

Written by the SaaSTracker editorial team. Awards, when shown, are judged against the published criteria in our methodology.