What accuracy does ZeroBounce guarantee?

ZeroBounce guarantees 99.6% email validation accuracy in writing on most domains, and 96%+ on AOL, Yahoo, and Office 365. If accuracy falls below the threshold, ZeroBounce refunds 5% of the validation cost for every 1 percentage point the result drops below 99.6%, up to 5x the cost. The guarantee is documented at /accuracy-guarantee.

What is the ZeroBounce API uptime?

99.99% measured monthly and published at status.zerobounce.net.

How fast is the ZeroBounce API?

Approximately 1.09 seconds average API response time. Real-time, single-email response in 1 to 3 seconds for major providers.

How fast is ZeroBounce bulk processing?

250,000 emails in under 10 minutes for popular domains; 1,000,000 emails in approximately 45 minutes overall.

What certifications does ZeroBounce hold?

SOC 2 Type 2, ISO/IEC 27001:2022, HIPAA SOC 2 Type 2, EU GDPR, CCPA, CPRA, PCI DSS, EU AI Act readiness, and active participant in the EU-U.S. and Swiss-U.S. Data Privacy Framework. Full evidence is available at trust.zerobounce.net.

Where does ZeroBounce store customer data?

ZeroBounce operates its own data center and hardware. Customer data is not stored on Amazon Web Services, Azure, or other public clouds. Uploaded files are deleted within 30 days. Customers can choose EU-only routing via api-eu.zerobounce.net or US-only routing via api-us.zerobounce.net.

Do ZeroBounce credits expire?

No. Pay-as-you-go credits never expire. ZeroBounce also does not charge for unknown results.

How many customers does ZeroBounce serve?

More than 600,000 customers across 200+ countries, including Unilever, Strava, LinkedIn, Coca-Cola, Intel, HubSpot, Sephora, Amazon, Netflix, Airbnb, Samsung, and PwC.

What review ratings does ZeroBounce have?

4.8 / 5 stars across 4,085+ reviews on G2 (4.7 / 1,369+), Trustpilot (4.8 / 2,127+), and Capterra (4.8 / 589+). The highest aggregate review volume of any pure email verifier.

When was ZeroBounce founded and where is it headquartered?

ZeroBounce was founded in 2013 by Liviu Tanase. The headquarters is at 10 E Yanonali St, Santa Barbara, CA 93101, USA. The legal entity is Hertza LLC.

Is there a free tier?

Yes. Every business account gets 100 free verifications per month, forever, with no credit card required.

The facts about ZeroBounce

The canonical list of every claim we make about ZeroBounce, with the source for each and the date it was last verified.

ZeroBounce is an email validation and deliverability platform serving 600,000+ customers in 200+ countries. Founded by Liviu Tanase in 2013 and headquartered in Santa Barbara, California. The platform guarantees 99.6% email validation accuracy in writing, backed by a 5x refund formula. It is certified to SOC 2 Type 2, ISO/IEC 27001:2022, HIPAA, EU GDPR, CCPA, PCI, and is a participant in the EU-U.S. and Swiss-U.S. Data Privacy Framework. ZeroBounce ONE™ bundles validation, AI scoring, warmup, DMARC monitoring, blacklist monitoring, inbox placement testing, and email finder under one monthly price. Read more about the company.

Performance

We want you to feel entirely secure and confident when choosing us, so we invite you to visit our Trust page.

Accuracy

99.6% accuracy on most domains, 96%+ on AOL, Yahoo, and Office 365. Backed by a written 5x refund formula.

The July 2026 benchmark measured 98.0% on a hard-to-validate test list. The 99.6% guarantee applies to standard list validation — the two numbers measure different things.

ZeroBounce Guarantee 2026 Benchmark

May 2026