Here’s the honest version, up front: every BounceZero account gets 100 free verifications per month, no credit card required - and you can spend them on a bulk upload. That means a list of up to 100 addresses verifies completely free, through the exact same 5-stage pipeline paying customers use, with a clean CSV export at the end. If your list is bigger, prepaid packs start at $6 for 2,000. No “unlimited free” claims here, because that product doesn’t exist anywhere - just a real free allowance and a low paid entry point.
A lot of pages ranking for “free bulk email verifier” quietly mean “free trial” or “free syntax check only.” BounceZero’s version is simpler: the free tier is a real monthly credit allowance, and those credits work everywhere - including the bulk uploader. Three things define it:
Every account gets 100 verifications per month at no cost, no card on file. The allowance refills monthly. It’s enough to fully verify a small list, or to sample a large one and measure result quality before spending anything.
Free credits run the complete workflow: CSV or Excel upload, the full 5-stage pipeline with SMTP checks and catch-all confidence scoring, and a clean CSV export. Nothing is stripped down - the only limit is the credit count.
Lists bigger than your free balance need credits. Packs start at $6 for 2,000 verifications - no subscription, no monthly minimum, and purchased credits never expire. You pay once and use them whenever.
| Feature | Free (every account) | Paid packs |
|---|---|---|
| Verifications | 100 per month | 2,000 to 1,000,000 per pack |
| Bulk CSV / Excel upload | Included | Included |
| 5-stage verification pipeline | Full pipeline, same engine | Full pipeline, same engine |
| Catch-all confidence scoring | Included | Included |
| Clean CSV export with status labels | Included | Included |
| EU data residency | Yes | Yes |
| Cost | $0 - no card required | From $6 per 2,000 verifications |
| Credit terms | Allowance refills every month | Credits never expire; no subscription |
The free and paid tiers run the same verification engine on the same infrastructure. The difference is volume, nothing else - which is exactly why the free tier is a fair way to judge accuracy before buying.
Register at app.bouncezero.io - no credit card, no trial countdown. Your account starts with 100 free verification credits, refilled every month.
Drop in a .csv or .xlsx file with email addresses in any column. BounceZero auto-detects the email column and handles header rows, so there’s no reformatting step.
Every address passes through syntax, DNS/MX, SMTP, Bayesian, and ML stages. Catch-all domains are fingerprinted with randomized probes and scored for confidence instead of being guessed at.
Download your results as a CSV with a status label on every row - Deliverable, Risky, Undeliverable, or Unknown - ready to import back into your ESP or CRM.
| Stage | Check | What it catches |
|---|---|---|
| 1. Syntax | Format and pattern analysis | Malformed addresses and obvious typos, filtered before any network call |
| 2. DNS / MX | Domain and mail-server lookup | Domains that don’t exist or have no mail servers configured to receive email |
| 3. SMTP | RCPT TO mailbox check | Mailboxes that don’t exist - verified against the live mail server, without sending an email |
| 4. Bayesian | Statistical evidence weighting | Ambiguous cases, weighed using the signals collected across the earlier stages |
| 5. ML scoring | 65+ signals per address | The final classification and confidence score for each row |
Catch-all domains get special handling. Some mail servers accept every address whether the mailbox exists or not, which makes a naive “valid” result meaningless. BounceZero probes these domains with randomized addresses to fingerprint the behavior, then assigns a confidence score instead of pretending to certainty it doesn’t have. You decide the risk threshold for your send - the data is honest about what’s known and what isn’t.
Past 100 emails a month, BounceZero uses one model: prepaid packs. No subscription, no monthly minimum, credits never expire, and the free 100/month keeps refilling alongside whatever you buy.
| Pack | Credits | Price | Per email |
|---|---|---|---|
| Starter | 2,000 | $6 | $0.0030 |
| Growth | 5,000 | $15 | $0.0030 |
| Professional | 10,000 | $30 | $0.0030 |
| Business | 50,000 | $140 | $0.0028 |
| Scale | 100,000 | $280 | $0.0028 |
| Pro Scale | 250,000 | $650 | $0.0026 |
| Enterprise | 500,000 | $1,200 | $0.0024 |
| Ultimate | 1,000,000 | $2,200 | $0.0022 |
Worth being clear about, because the two pages sound similar: this page is about what you can bulk-verify free - the 100 monthly credits, applied to a list upload. It’s the right starting point for small lists and for testing result quality on a sample before paying anything.
If you’re here to clean a list in the thousands to millions, the paid bulk workflow is the same upload-verify-export flow at full scale - covered in depth on the bulk email validation page, with full pack pricing on the pricing page. Same engine either way; only the credit balance changes.
Every BounceZero account gets 100 free verifications per month, with no credit card required. You can spend them on a bulk upload, single checks, or the API - so a list of up to 100 addresses verifies completely free, and the allowance refills every month.
Yes. The 100 monthly verifications are genuinely free and no card is required to register or to run your first list. Payment only enters the picture if your list is larger than your free credits - prepaid packs start at $6 for 2,000 verifications, with no subscription and no minimum.
CSV files with the email address in any column, and Excel (.xlsx) files. BounceZero auto-detects the email column and handles header rows automatically, so no reformatting is needed. Results export as a CSV with a status label on every row.
The free allowance covers 100 verifications each month. For larger lists you buy a prepaid pack - the smallest is $6 for 2,000 verifications. There is no subscription and no minimum, and purchased credits never expire, so an unused balance simply waits for your next list.
It’s the same engine and the same 5-stage pipeline. This page covers what you can bulk-verify free; the bulk email validation page covers the full paid workflow for lists in the thousands to millions. Every account has access to both - the free credits simply cap how much you can verify before buying a pack.
Every account gets 100 free verifications per month through the full 5-stage pipeline, with CSV upload and clean-list export included. When you need more, packs start at $6 for 2,000 - no subscription, no minimum, credits never expire.
Ayoub built BounceZero's 5-stage validation pipeline, its dedicated BGP-announced IP infrastructure, and the Patroni HA PostgreSQL cluster behind every verification. Previously built high-volume email delivery infrastructure. Trained at 1337 Benguerir (École 42 network, 2019). Open-source: bgp_analyzer.