Best Email Verification APIs
Opinionated picks for email verification apis, with the trade-offs up front, judged from each API’s published, cited data. The reasoning is shown, so disagree where you know better. Compare all 10 →
Best overall: ZeroBounce
Accurate, fast and secure email verification service
From $39 2,000 emails · free tier available.
How it stacks up
- ✓ On compliance, ZeroBounce additionally documents SOC 2, HIPAA.
- ✓ On compliance, ZeroBounce additionally documents SOC 2, HIPAA.
- ✓ ZeroBounce offers a free tier while Clearout does not, so ZeroBounce is easier to trial before committing.
Best for: Prototypes and side projects - free to start, no sales call; Regulated or enterprise workloads - compliance attestations and an enterprise plan; AI agents and automation - an agent-ready surface (MCP / llms.txt).
At a glance
| # | API | Best for | Starting price | Score |
|---|---|---|---|---|
| 1 | ZeroBounce | Best overall · Best free pick · Best for enterprise · Best for agents | $39 2,000 emails | 85 |
| 2 | Hunter | Broadest surface | $49 month | 74 |
| 3 | Verifalia | Cheapest to start | $9 month | 60 |
| 4 | Clearout | transparent public pricing | $21 3,000 credits | 61 |
| 5 | Emailable | transparent public pricing | $25.50 month | 68 |
| 6 | Bouncer | transparent public pricing | $8 1,000 emails | 61 |
| 7 | Kickbox | transparent public pricing | $5 500 verifications | 73 |
| 8 | AbstractAPI Email Validation API | transparent public pricing | $17 month | 77 |
| 9 | NeverBounce | transparent public pricing | $8 1,000 emails | 49 |
| 10 | MillionVerifier | transparent public pricing | $4.90 2,000 credits | 50 |
Quick pick by use case
- If you want the strongest all-round pick, pick ZeroBounce - our default pick: strongest across pricing, trust and breadth.
- If you want to start free, pick ZeroBounce - free tier: 100 free monthly email verifications, 10 free Email Finder queries, 1 Email Inbox Placeme….
- If you're buying for a regulated or large team, pick ZeroBounce - for regulated or large teams: SOC 2 Type II, HIPAA, published SLA.
- If you want the lowest published entry price, pick Verifalia - from $9 month to start; compare on your real usage, not the entry price.
- If you're wiring this into coding agents or AI workflows, pick ZeroBounce - easiest to wire up programmatically: MCP server + llms.txt.
- If you want the broadest documented surface, pick Hunter - 31 documented actions; breadth isn't quality, but it's the most to build on.
The picks in depth
#1 ZeroBounce
85 / 100- Best overall
- Best free pick
- Best for enterprise
- Best for agents
Accurate, fast and secure email verification service
PricingUsage · from $39 2,000 emails · free tier ✓TrustSOC 2 Type II · HIPAA · GDPR · ISO 27001 · PCI DSSDoesUsed byAirbnb, Intel, LinkedIn, SamsungStrengthstransparent public pricing · a free tier · self-serve signupScoresAgent 55 · Pricing 100 · Setup 100 · Docs 55 · Procurement 100 · Trust 100#2 Hunter
74 / 100- Broadest surface
A free email checker to instantly spot risky or fake email addresses. Verify emails with thorough checks: format, domain information, servers response, accept-all.
PricingHybrid · from $49 month · free tier ✓TrustGDPRDoesUsed bySemrush, Vimeo, Cisco, CanvaStrengthstransparent public pricing · a free tier · self-serve signupThe catchVerification is a secondary feature: Hunter is built for finding and prospecting emails, not bulk list hygiene.ScoresAgent 70 · Pricing 100 · Setup 100 · Docs 60 · Procurement 100 · Trust 15#3 Verifalia
60 / 100- Cheapest to start
Email list cleaning and real-time email verification service
PricingHybrid · from $9 month · free tier ✓TrustGDPR · ISO 27001DoesStrengthstransparent public pricing · a free tier · self-serve signupAvoid ifYou have strict compliance requirementsScoresAgent 20 · Pricing 100 · Setup 75 · Docs 15 · Procurement 100 · Trust 50#4 Clearout
61 / 100Clearout is a real-time data quality engine that helps sales, marketing, customer success, product, and operations (Go-To-Market) teams maintain their contact data in a clean, accurate, and conversion-ready state.
PricingHybrid · from $21 3,000 credits · free tier ✗TrustSOC 2 Type II · GDPR · ISO 27001DoesUsed bySigParser, Pearl Lemon, Logic InboundStrengthstransparent public pricing · self-serve signup · SOC 2 Type IIAvoid ifYou want to try it free before payingScoresAgent 35 · Pricing 85 · Setup 50 · Docs 55 · Procurement 85 · Trust 55#5 Emailable
68 / 100The most accurate email verification platform
PricingUsage · from $25.50 month · free tier ✗TrustSOC 2 Type II · GDPR · ISO 27001DoesUsed byleadlovers, Funky Christmas JumpersStrengthstransparent public pricing · self-serve signup · SOC 2 Type IIAvoid ifYou want to try it free before payingScoresAgent 55 · Pricing 85 · Setup 65 · Docs 45 · Procurement 85 · Trust 75#6 Bouncer
61 / 100Bouncer Email Verification API lets you validate email address and verify its deliverability, in the way you want.
PricingUsage · from $8 1,000 emails · free tier ✗TrustSOC 2 Type I · GDPRDoesUsed byVipeCloud, ActivePipe, BigMailer, BookYourDataStrengthstransparent public pricing · self-serve signup · SOC 2 Type IAvoid ifYou want to try it free before payingScoresAgent 55 · Pricing 85 · Setup 65 · Docs 45 · Procurement 85 · Trust 33#7 Kickbox
73 / 100Kickbox is your all-in-one email verification platform, packed with the features, integrations and security you need to keep your email data clean and deliverable.
PricingUsage · from $5 500 verifications · free tier ✓TrustGDPRDoesUsed byReddit, The Zebra, Kayak, Capital OneStrengthstransparent public pricing · a free tier · self-serve signupAvoid ifYou have strict compliance requirementsScoresAgent 55 · Pricing 100 · Setup 100 · Docs 45 · Procurement 100 · Trust 35#8 AbstractAPI Email Validation API
77 / 100Verify Any Email in Real Time
PricingHybrid · from $17 month · free tier ✓TrustSOC 2 Type II · GDPRDoesUsed byCompass, Wolters Kluwer, Salesforce, GoogleStrengthstransparent public pricing · a free tier · self-serve signupScoresAgent 55 · Pricing 100 · Setup 100 · Docs 45 · Procurement 100 · Trust 60
How we rank
The headline score is the average of six 0-100 axes computed only from each API’s published, sourced fields: agent-friendliness, pricing transparency, setup speed, docs quality, procurement ease, and trust readiness. An unknown signal scores 0 for its axis - we credit what’s confirmed, never guess. The score is one input, not the verdict: we lead with each pick’s trade-off, and where a job has only one real option we say so rather than crown it. Full method on the methodology page.
Why trust apio
- ✓ Every field cited. Each profile links the source for every claim - check us.
- ✓ Public audit log. Every change to this data is recorded per field, with who changed it and why.
- ✓ Published, deterministic methodology. The score is a formula over the same fields you can see - recompute it yourself.
- ✓ Zero affiliate links, zero ads, zero paid placement. Money never moves rank.
- ✓ No reviews yet - and we say so rather than synthesizing them.
Frequently asked questions
What is the best email verification api?
ZeroBounce is our current top pick across pricing, trust, and developer-surface data (from $39 2,000 emails). The right pick depends on your constraint: if you want the strongest all-round pick, ZeroBounce; if you want to start free, ZeroBounce; if you're buying for a regulated or large team, ZeroBounce.
How are these Email Verification APIs ranked?
By a transparent data-readiness score computed from each API's published, sourced fields: pricing, free tier, self-serve access, compliance, webhooks/sandbox, and capability breadth. No reviews, no paid placement.
Which Email Verification APIs have a free tier?
ZeroBounce, Hunter, Verifalia, Kickbox, AbstractAPI Email Validation API.