AT Valid vs ZeroBounce
AT Valid's AT Valid Score engine grades catch-all confidence, scores toxicity, analyzes the recipient domain's own website and produces a full List Quality Report on every list β compared honestly against ZeroBounce's publicly advertised accuracy, pricing and toolkit.
Last updated: September 2026 Β· ZeroBounce information from public sources, referenced below
TL;DR β Our honest verdict
AT Valid runs AT Valid Score, an 11-step engine that goes beyond a valid/invalid answer: a graded 0β10 catch-all confidence score, a 0β5 toxicity index, website/domain analysis of the recipient's own domain, and a List Quality Report with a projected bounce rate on every bulk job β plus recurring list monitors, an encrypted cache that makes re-validating the same list free for 30β90 days, and multi-pass greylist retries at no extra credit. It does this at $269 per 100,000 validations, versus ZeroBounce's published $649 pay-as-you-go, with 200 free credits at signup and credits that never expire. ZeroBounce is a long-established name with a broader product line, including an email finder and engagement data, for teams that specifically want those extra tools from a single vendor. If what you need is a validation engine that tells you why an address is risky and keeps your list clean over time, AT Valid was built for exactly that.
About AT Valid
AT Valid runs AT Valid Score, an 11-step, 20+ check validation engine: RFC 5322 syntax plus provider-specific username rules, full DNS/MX/SPF/DMARC/DKIM analysis with Null MX and transient-failure detection, a real SMTP mailbox check with IP rotation and multi-pass greylist retry, and a graded catch-all confidence score (0β10) instead of a blind "unknown". It also analyzes the recipient domain's own website for parked, for-sale or ad-monetized pages, scores every address on a 0β5 toxicity index, and checks it against an encrypted, HMAC-keyed result cache, so a list re-validated within 30β90 days costs 0 credits.
Every bulk job produces a List Quality Report (health score, projected bounce rate, segments, top issues and recommendations), and organizations on GROWTH+ can turn any list into a recurring monitor with weekly, bi-weekly or monthly re-checks and delta/webhook alerts. The platform also includes a deliverability kit (blacklist/RBL monitors for domains and IPs), Have I Been Pwned breach intelligence (ENTERPRISE), a 7 KB real-time widget with sub-status messages, a free single-address validator with no signup, native integrations (Salesforce, HubSpot, RD Station, Mailchimp, Pipedrive, Zapier, webhooks) and a verifiable public ESG certificate β all built with LGPD and GDPR in mind, in five languages, at $269 per 100,000 validations with credits that never expire.
About ZeroBounce
ZeroBounce was founded in 2015 by Liviu Tanase and is headquartered in Santa Barbara, California. The company advertises 99%-accurate email validation and states it serves more than 400,000 customers, from solo senders to large global brands. Its published product line goes beyond core validation to include an Email Finder, Activity Data engagement insights and a deliverability toolkit with inbox placement tests, blacklist monitoring and warmup features, and it publishes its own pricing and documentation at zerobounce.net.
Feature-by-feature comparison
| Feature | AT Valid | ZeroBounce |
|---|---|---|
| Founded | 2024, Brazil | 2015, Santa Barbara, USA (per ZeroBounce) |
| Advertised accuracy | 99.5% with 20+ verification checks (AT Valid Score) | 99% (advertised on zerobounce.net) |
| Free credits | 200 at signup, no credit card | 100 per month on the freemium plan (per ZeroBounce docs) |
| Credit expiry | Credits never expire | Credits never expire (per ZeroBounce docs) |
| Real-time validation API | Yes | Yes (advertised) |
| Bulk list validation | Yes | Yes (advertised) |
| Price per 100,000 validations | $269 ($0.0027 per email) | $649 pay-as-you-go (published pricing, Sept 2026) |
| Platform interface languages | 5: English, Portuguese (BR), Spanish, Chinese, German | Not publicly documented |
| Verifiable CO2-avoidance certificate (ESG) | Yes, public and verifiable | No comparable feature among its published products |
| Native RD Station integration | Yes | Not publicly listed |
| Website/domain analysis of the recipient domain | Flags parked, for-sale, redirecting or ad-monetized domains | Not publicly documented |
| Catch-all confidence score | Graded 0β10 (real-name signal, corporate gateway, domain maturity) instead of a blind βunknownβ | Not publicly documented |
| Toxicity / spam-trap risk index | 0β5 toxicity index on every result | Not publicly documented |
| List Quality Report on bulk jobs | Health score AβF, projected bounce rate before/after cleaning, segments, top issues and recommendations | Not publicly documented |
| Recurring list monitors | Weekly/bi-weekly/monthly re-validation with delta and webhook, included from the GROWTH plan | Not publicly documented |
| Blacklist/RBL monitoring (domains & IPs) | Included, with alerts and history | Not publicly itemized as a standalone, included feature |
| 0-credit re-validation cache | Encrypted result cache: re-checking an address validated in the last 30β90 days costs 0 credits | Not publicly documented |
| Multi-pass greylist retry | 450/451 automatically re-checked after a wait window, up to 3 passes (Enterprise), no extra credit | Not publicly documented |
| Real-time client-side widget | 7 KB gzip, sub-status messages, per-key + per-IP anti-flood | Not publicly documented |
| Free single-address validator | 10 checks/day, no signup, at atvalid.com/validate-email | Not publicly documented |
| Have I Been Pwned breach intelligence | Exposure rate, breach count and data classes as an activity signal (ENTERPRISE) | Not publicly documented |
| Provider-specific username rules | Rejects impossible usernames (e.g. Gmail 6β30 chars) in ~1ms, before any SMTP check | Not publicly documented |
| Data protection posture | Designed with LGPD and GDPR requirements in mind | Publishes its own privacy documentation |
AT Valid data reflects our published product information. ZeroBounce data comes from ZeroBounce's website, documentation and published pricing as of September 2026. "Not publicly documented" means we could not verify the item in public sources β most of these are AT Valid Score capabilities specific to AT Valid's own engine, with no direct published ZeroBounce equivalent to compare against. Always confirm details on each provider's site.
Key differences
A domain check ZeroBounce doesn't publish
AT Valid inspects the recipient domain's own website, flagging parked, for-sale, redirecting or ad-monetized pages as a risk signal. It's part of AT Valid Score's 11-step engine, and not a check ZeroBounce documents publicly.
A graded answer, not a shrug
Instead of a flat "unknown" for catch-all domains, AT Valid grades its confidence 0β10 using real-name signals, corporate gateways and domain maturity β plus a 0β5 toxicity index on every address.
A report, not just a list
Every bulk job gets a List Quality Report: health score AβF, projected bounce rate before and after cleaning, toxicity distribution and concrete recommendations. Turn any list into a recurring monitor (weekly/bi-weekly/monthly) from the GROWTH plan.
Re-checks that don't cost you twice
An encrypted result cache means an address validated in the last 30β90 days is reused at 0 credits. Greylisted addresses get up to 3 automatic retry passes at no extra charge.
Built where it validates
Have I Been Pwned breach intelligence (ENTERPRISE) and a public, verifiable ESG certificate β neither of which ZeroBounce lists among its published products.
Lower published pricing, credits that never expire
For 100,000 validations, AT Valid's published price is $269 versus ZeroBounce's pay-as-you-go $649 (September 2026). Credits never expire, and subscriptions get a further 20% off.
When ZeroBounce may be the better choice
There are genuine reasons to pick ZeroBounce, and pretending otherwise would help nobody:
- You want an email finder, engagement data and a broader deliverability suite from one vendor, alongside validation β ground AT Valid deliberately does not cover.
- You specifically value a long, US-based track record: the company has operated since 2015 and advertises a customer base of more than 400,000.
When AT Valid is the better choice
AT Valid is the stronger fit when the priorities below sound like yours:
- You want more than a valid/invalid verdict β a graded catch-all confidence score, a toxicity index and a List Quality Report on every list.
- You send to the same list repeatedly β recurring monitors and the encrypted 0-credit cache mean you do not pay twice to re-check addresses you already validated.
- You need blacklist/RBL monitoring for your sending domains and IPs, included rather than sold separately.
- Price and credit expiry matter β $269 per 100,000 validations, credits that never expire, and 20% off subscriptions.
- You want a public, verifiable ESG certificate for sustainability reporting alongside your list hygiene program.
Pricing comparison
Both platforms sell validation credits with volume discounts. The anchors below use each provider's published pay-as-you-go pricing as of September 2026 β pricing changes, so confirm current pricing on each provider's site before deciding.
On AT Valid, the sticker price is often not what you pay: subscriptions get a further 20% off, and any address already validated in the last 30β90 days is reused free from the encrypted result cache β so re-validating the same list repeatedly can cost a fraction of the price below.
AT Valid
Lower published priceZeroBounce
Switching from ZeroBounce to AT Valid
Export your list
Download your contacts as a CSV from ZeroBounce or directly from your email platform or CRM. Your data is yours β there is no lock-in on either side.
Create a free account
Sign up at AT Valid and receive 200 free credits instantly, no credit card required. Validate a real sample and compare the results with your previous provider.
Upload, validate and connect
Run your full list through bulk validation, then connect the real-time API or a native integration (Salesforce, HubSpot, Mailchimp, RD Station, Pipedrive, Zapier) to keep new signups clean.
Frequently asked questions
Is AT Valid a good ZeroBounce alternative?
Yes. AT Valid runs AT Valid Score, an 11-step engine with 20+ checks including a graded catch-all confidence score, a toxicity index, website/domain analysis and a full List Quality Report on every bulk job, at $269 per 100,000 validations versus ZeroBounce's published $649. You also get 200 free credits at signup, credits that never expire, recurring list monitors from the GROWTH plan, and a verifiable CO2-avoidance certificate. ZeroBounce remains a reasonable choice if you specifically need its wider toolkit, such as its email finder and engagement data, alongside validation.
Can I migrate my lists from ZeroBounce to AT Valid?
Yes. Export your contacts as a CSV file from ZeroBounce or your email platform, create a free AT Valid account and upload the file for bulk validation. There is no lock-in on either side, and your 200 free credits let you test with a real sample before committing.
How accurate is AT Valid compared to ZeroBounce?
AT Valid delivers 99.5% accuracy using AT Valid Score, an 11-step engine with more than 20 verification checks, including SMTP, DNS/MX, disposable and catch-all detection, and toxicity scoring. ZeroBounce advertises 99% accuracy on its website. Both figures are self-reported, so we recommend validating the same sample list on both platforms and comparing the results yourself.
How do the free credits compare?
AT Valid gives every new account 200 free credits at signup, with no credit card required, and credits never expire. ZeroBounce documents up to 100 free validation credits per month on its freemium plan. If you want a larger free test up front, AT Valid gives you twice as many credits on day one.
What is the CO2-avoidance certificate?
When you remove invalid addresses, you stop sending emails that would never be read, which avoids unnecessary carbon emissions. AT Valid issues a public, verifiable certificate quantifying the CO2 avoided by your list cleaning, ready to use in ESG and sustainability reporting. ZeroBounce lists no comparable feature among its published products.
What does AT Valid check that ZeroBounce does not publish?
AT Valid's AT Valid Score engine analyzes the recipient domain's own website for parked, for-sale or ad-monetized pages, grades catch-all domains with a 0-10 confidence score instead of a blind "unknown", scores every address on a 0-5 toxicity index, and turns every bulk job into a List Quality Report with a projected bounce rate, segments and recommendations. None of these are documented in ZeroBounce's public materials.
Do I pay twice to re-validate the same list?
No. AT Valid's encrypted result cache reuses an address you validated in the last 30 days, or 90 days for disposable, dead-domain and typo results, at 0 credits. You can also turn any list into a recurring monitor, weekly, bi-weekly or monthly, that only charges for the addresses that actually changed.
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