Best email verifier for Klaviyo: 7 options compared

Which email verifier should I use for Klaviyo?

What it is

Email verification with a real SMTP mailbox check: each address comes back valid, risky or invalid with a reason. Includes an email finder on Pro and up.

Price per check

Starter $9/mo for 2,500 ($3.60 per 1,000); Pro $39/mo, 100,000 a month at full speed ($0.39 per 1,000 when used), then slower, never cut off. Business $99/mo with 300,000 at full speed; Agency $249/mo with 750,000 at full speed.

One-time packs

10,000 for $15 ($1.50 per 1,000); 25,000 for $29 ($1.16 per 1,000); 50,000 for $49 ($0.98 per 1,000); 100,000 for $79 ($0.79 per 1,000); 250,000 for $169 ($0.68 per 1,000). Credits never expire, run at standard speed, CSV verification only (no API or finder).

Free checks

First 100 email checks free with a Google sign-in, no card, once per account. Single checks on the free email checker need no account.

Billing

Monthly subscription, cancel anytime (yearly billing optional). One-time packs are listed above. Starter allowances reset monthly and do not roll over.

Speed today

One sending IP today, shared by every customer: about 13,000 mailbox checks a day in the standard lane. Bad syntax, dead domains and disposable addresses return at once; a list of 100,000 takes days, not hours, and each job shows its estimated finish time.

Catch-all handling

Catch-all (accept-all) addresses stay risky, never valid, and are graded higher, medium or lower likelihood with the reasons. Anything a mail server does not confirm is risky.

API and MCP

REST API on Pro, Business and Agency (Pro includes 10,000 calls a month, then $1.50 per 1,000). Remote MCP server with 6 tools for Claude, ChatGPT, Cursor and VS Code. No API on Starter.

Integrations

Connects to Instantly, Smartlead, HubSpot and Mailchimp by API key: verifies a campaign or list and tags each contact with its result. CSV in and out for any other tool.

Phone

Free phone format checks (country, type range). Live carrier and line-type lookups come with Pro + Phone at $49.99/mo (5,000 a month). It never says a number is in service.

What it does not do

No sending, warmup or inbox placement tests. No published accuracy benchmark against other verifiers. Catch-all domains, Yahoo and AOL cannot be confirmed, and Outlook.com and Hotmail mailboxes are not probed while Microsoft refuses checks from our server's network: all of these come back risky, never valid.

SimpleVerifier facts from our pricing page and product. Last updated October 31, 2026.

Which one should you pick?

• Pick DeBounce if you want a low price on a one-off clean of a small or medium list, with pay-as-you-go credits that never expire.

• Pick Emailable if you want 250 free credits to test with and credits that never expire.

• Pick Clearout if you pay yearly and also want an email finder and prospecting on the same credit balance.

• Pick Bouncer if you also want inbox placement and blocklist tests from the same vendor (its Deliverability Kit is a separate plan).

• Pick Kickbox if you want unknown results refunded as credits, or deliverability consulting alongside verification.

• Pick ZeroBounce if you will use what its subscription bundles (inbox placement tests, blacklist monitoring, warmup), or want a free allowance that refills every month.

• Pick SimpleVerifier if you verify or re-check lists every month and want one flat monthly price instead of credits, with catch-all addresses kept risky rather than marked valid.

  Skip SimpleVerifier if you want the lowest price for one small list, where another vendor's pack can cost less (cost by list size); you need your data processed only inside the EU (our service providers process data in several countries, including the US); or your list is mostly Outlook.com, Hotmail or Live addresses, which Microsoft currently won't let us confirm, so they come back risky (why).

How we compared

On 27 October 2026 we read each vendor's integrations page or help center for Klaviyo (prices were read the same day), and list those pages under each tool. "None found" means we did not find one that day, not that it is impossible: most tools also have an API or Zapier. NeverBounce returned a bot check instead of its page, so that row says "not confirmed". We checked 10 verifiers; to keep the table short it shows the ones that list a Klaviyo connection and the lowest-priced CSV options, and leaves out EmailListVerify, MillionVerifier, NeverBounce and Hunter, which are in the main roundup. We did not run an accuracy benchmark, so nothing here ranks accuracy: test a shortlist on a sample of your own list, including addresses you know are dead.

Each tool in a few lines

1. 1. DeBounce

   Best for: Small and medium lists cleaned once or monthly

   • Pay-as-you-go credits never expire
   • 100,000 credits are $135 one-time
   • Watch out: Every pass over the same list is billed again

   Checked October 27, 2026: DeBounce pricing · DeBounce integrations · DeBounce integrations

2. 2. Emailable

   Best for: Buyers who want credits that never expire

   • 250 free credits on signup
   • The subscription saves 15% and can be cancelled
   • Watch out: Per-credit pricing: 100,000 a month is $357 on the subscription

   Checked October 27, 2026: Emailable pricing · Emailable integrations

3. 3. Clearout

   Best for: Annual buyers who also want an email finder and prospecting

   • Unused plan credits roll over, by its pricing page
   • Verification, finder and prospecting share one balance
   • Watch out: The monthly-billed price for 10,000 is well above the yearly rate

   Checked October 27, 2026: Clearout pricing · Clearout integrations

4. 4. Bouncer

   Best for: Teams that also want inbox placement and blocklist tests

   • Credits never expire
   • Deliverability Kit (inbox placement, blocklist tests) from $25 a month
   • Watch out: The Deliverability Kit is a separate plan from verification

   Checked October 27, 2026: Bouncer pricing · Bouncer integrations

5. 5. Kickbox

   Best for: Senders who also want deliverability consulting

   • Unknown results are refunded as credits, by its pricing page
   • Watch out: No subscription; every list is a per-email purchase

   Checked October 27, 2026: Kickbox pricing · Kickbox integrations

6. 6. ZeroBounce

   Best for: Teams that want a deliverability suite in one plan

   • The free allowance refills every month
   • ONE bundles warmup, inbox tests and blacklist monitoring
   • Watch out: Pay as you go starts at $39 for 2,000 credits

   Checked October 27, 2026: ZeroBounce pricing · ZeroBounce integrations

7. 7. SimpleVerifier(our tool)

   Best for: Lists checked every month, re-checks, and campaign tools it connects to

   • Connects to Instantly, Smartlead, HubSpot and Mailchimp by API key and tags each contact valid, risky or invalid
   • Catch-all addresses stay risky, never valid
   • Watch out: One-time packs run at standard speed and cover CSV verification only (no API or finder)
   • Watch out: Starter's allowance resets monthly and does not roll over, and has no API; 10,000 a month needs Pro

   Checked October 27, 2026: SimpleVerifier pricing · SimpleVerifier integrations

Common questions

How do I verify Klaviyo contacts with SimpleVerifier?

There is no Klaviyo connector, so it is a CSV round trip. Export: In Klaviyo, go to Audience > Lists & segments. Click into the list or segment. Open the Manage list (or Manage segment) dropdown. Choose Export list to CSV and pick the properties to include. Upload that file to SimpleVerifier as it is; the email column is found automatically. You get three files, valid, risky and invalid, each with every original column, so import the valid file back into Klaviyo. The export steps follow Klaviyo's help article; the full Klaviyo export guide has the details.

Can I verify new contacts automatically instead of exporting?

Yes, with the SimpleVerifier API, which comes with Pro and higher plans. Call it from Zapier, Make or n8n when a contact is created, and branch on the status field: valid, risky or invalid. There is no packaged SimpleVerifier app in those directories yet; the guides use their HTTP or webhook steps.

Which email verifiers integrate with Klaviyo?

On 27 October 2026: DeBounce, Emailable, Bouncer, Kickbox and ZeroBounce listed Klaviyo on their own integrations pages, and Clearout listed it through Zapier. NeverBounce's site blocked our check. SimpleVerifier has no Klaviyo connector; the free Klaviyo list cleaner checks a sample.

Is the cheapest verifier the most accurate?

We did not run an accuracy benchmark, so nothing here ranks accuracy: test a shortlist on a sample of your own list, including addresses you know are dead.