Spaw vs NeverBounce
NeverBounce is a ZoomInfo-owned email verification service with a bulk list-cleaning workflow, a real-time API and official client libraries in six languages.
The table uses NeverBounce's public pricing and documentation pages as checked on 2026-09-03, and Spaw's own pricing page. A row those pages carry no value for is marked "not on the pages read" rather than guessed at, and that is a statement about the reading and not about what NeverBounce publishes.
| spaw | neverbounce | |
|---|---|---|
| Pricing model | Pay-as-you-go credit packs whose credits never expire, or optional plans, billed monthly or yearly, that deposit the same credits every month for less and roll unused plan credits over up to three months' allowance; both through Stripe Checkout | not on the pages read |
| Free tier | 100 free credits every month, no card required | not on the pages read |
| Price per 1,000 at about 10k | $7.80 (Growth pack: 5,000 credits for $39), or $5.80 on the Growth monthly plan (5,000 credits for $29 a month) | not on the pages read |
| Price per 1,000 at about 100k | $4.49 (Volume pack: 100,000 credits for $449), or $3.49 on the Volume monthly plan (100,000 credits for $349 a month) | not on the pages read |
| Unknown or catch-all results billed | No: an unconfirmed mailbox (reason unverified) and an answer Spaw could not obtain because its handshake partner was unavailable are free and leave no 7-day repeat marker, so a later lookup is a fresh one; a catch-all answer costs 1 credit like any risky answer, and an automatic re-check bills 1 credit only when it confirms the mailbox | not on the pages read |
| Undeliverable results billed | No, within a fair use: undeliverable answers that needed a mailbox probe are free up to max(500, your billed email answers) in a rolling 30 days, then 1 credit each; the rest are always free | not on the pages read |
| SMTP mailbox check | Yes | not on the pages read |
| Catch-all handling | A catch-all answer is remembered per domain for 7 days, and every unconfirmed mailbox carries a published 0 to 100 mailbox_confidence estimate | catchall is one of the result codes alongside valid, invalid, disposable and unknown; jobs with a high rate of unknowns can be sent for a manual review |
| Bulk limit | 100,000 addresses per bulk job, with an HMAC-signed completion webhook | Lists of millions should be split into jobs of 1,000,000 addresses; 10 concurrent jobs and at most 50 runs a day per account, and no more than 10 jobs per 100,000 items an hour |
| Batch API | 50 addresses per synchronous request, probes sent concurrently | Bulk jobs through the jobs API (create, status, download) |
| Rate limit | 5 requests per second per key on the email and consistency endpoints | Job creation limits as above; per-request limits for the single-check endpoint are not published on the pages checked |
| Official SDKs | Python, Node.js, PHP | PHP, Node.js, Python, Ruby, Go, .NET |
| Data retention | Only email verification keeps a history row, for 30 days, then pruned; test addresses are never logged | not on the pages read |
checked 2026-09-03 · sources: NeverBounce usage guidelines, NeverBounce verifying a list, NeverBounce GitHub organization
When NeverBounce fits better
Teams that clean large lists through jobs and want official wrappers in six languages plus an n8n node.
- Official n8n node
- Manual review process for jobs with many unknown results
- Owned by ZoomInfo
When Spaw fits better
Developers who want one flat price per answered lookup across every signal a signup form produces, a transparent risk score, and an API that documents every field.
- NeverBounce's pricing pages blocked automated reading when we checked, so its rates are not reproduced here; Spaw's packs and free grant are listed at spaw.co/pricing
- Spaw runs the SMTP handshake on every lookup and bills nothing for undeliverable verdicts within a fair-use allowance
- Spaw's bulk jobs take 100,000 addresses with a signed completion webhook; NeverBounce asks for 1,000,000-address chunks, 10 concurrent jobs and 50 runs a day
- Spaw returns 46 named fields and a machine-readable reason per address
Questions
Does Spaw charge for catch-all or unknown results?
Spaw bills per answer, not per probe outcome. A catch-all domain comes back risky with reason catch_all and costs 1 credit like any risky answer. A mailbox the handshake could not confirm (greylisting, a timeout, no definite answer) comes back risky with reason unverified and is free, and so is an answer Spaw could not obtain at all because its handshake partner was unavailable; neither leaves a 7-day repeat marker, so a later lookup is a fresh one (an uncertain result is reused for up to 15 minutes, then the mailbox is asked again) and bills 1 credit only once the mailbox is confirmed, and the automatic re-checks behind callback_url bill 1 credit only when they confirm it. Undeliverable verdicts are free within a fair use of max(500, your billed email answers) in a rolling 30 days, and invalid input and repeats within 7 days are free too. NeverBounce does not publish how it bills them.
Can I move a list from NeverBounce to Spaw?
Yes. Upload the CSV to the dashboard or POST it to the bulk endpoint; Spaw keeps your columns, adds the verdict columns, and lets you download only the deliverable, risky or undeliverable rows. Addresses that come back undeliverable join your suppression list so later runs skip them for free.
Is there a free tier?
Every Spaw account receives 100 free credits at the start of each month with no card on file, and unused free credits accumulate. NeverBounce does not publish a free tier on the pages checked.
Try Spaw on your own list
Free credits every month, no card. Upload a list, keep your columns, and download only the rows you want. See the pricing page for every rule, or the NeverBounce alternatives.
NeverBounce is a trademark of its owner. Spaw is not affiliated with it. Markdown version: /compare/neverbounce.md