Spaw vs Abstract API
Abstract API's email validation endpoint is one of a family of utility APIs sold as monthly request quotas with a free 100-request plan.
The table uses Abstract API's public pricing and documentation pages as checked on 2026-09-03, and Spaw's own pricing page. A value the vendor does not publish is marked as such.
| spaw | abstract api | |
|---|---|---|
| Pricing model | Pay-as-you-go credit packs bought through Stripe Checkout; no subscription, credits never expire | Monthly subscription tiers with a request slider from 5,000 to 150,000 requests a month; Starter from $17, Standard from $37, Professional from $39 a month |
| Free tier | 10 free credits every month, no card required | 100 requests a month |
| Price per 1,000 at about 10k | $7.80 (Growth pack: 5,000 credits for $39) | not published |
| Price per 1,000 at about 100k | $4.99 (Volume pack: 100,000 credits for $499) | not published |
| Unknown or catch-all results billed | Yes, by verdict: a deliverable or risky answer costs 1 credit even when the mailbox is unconfirmed; the automatic re-checks are free | Yes |
| Undeliverable results billed | No, undeliverable verdicts are always free | Yes |
| SMTP mailbox check | Yes | Yes |
| 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 | Catch-all detection on all plans; every request counts against the quota |
| Bulk limit | 100,000 addresses per bulk job, with an HMAC-signed completion webhook | Bulk CSV upload from the Starter plan up |
| Batch API | 50 addresses per synchronous request, probes sent concurrently | not published |
| Rate limit | 5 requests per second per key | 3 requests a second on paid tiers |
| Official SDKs | Python, Node.js, PHP | not published |
| Data retention | Lookup history kept for 30 days, then pruned; test addresses are never logged | not published |
checked 2026-09-03 · sources: Abstract API email validation page
When Abstract API fits better
Developers who want one vendor for several small utility APIs under a monthly quota.
- Quality score, risk assessment, breach detection and role detection are Professional-plan features
- SOC 2 Type II and GDPR, CCPA statements
- A commercial license is listed under the Enterprise plan
When Spaw fits better
Developers who want one flat price per answered lookup, a transparent risk score, and an API that documents every field.
- Abstract's quality score and role detection sit on its Professional plan; Spaw returns all 27 fields, including risk_score and role, on every lookup
- Abstract counts every request against the quota; Spaw bills per answered lookup
- Abstract's stated rate limit is 3 requests a second; Spaw's is 5
- Spaw's bulk jobs take 100,000 addresses through the API with a signed webhook
Questions
Does Spaw charge for catch-all or unknown results?
Spaw bills per answer, not per probe outcome: a lookup that comes back deliverable or risky costs 1 credit even when the mailbox could not be confirmed, for example on a catch-all domain or after greylisting. Undeliverable verdicts, invalid input, repeats within 7 days and the automatic re-checks behind callback_url are free. Abstract API counts them according to its public pages.
Can I move a list from Abstract API 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 10 free credits at the start of each month with no card on file, and unused credits accumulate. Abstract API offers: 100 requests a month.
Try Spaw on your own list
10 free lookups a 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 Abstract API alternatives.
Abstract API is a trademark of its owner. Spaw is not affiliated with it. Markdown version: /compare/abstract.md