StopBouncingClean your Klaviyo list.
Stop bounces before they start.
Invalid email addresses in Klaviyo raise your bounce rate, damage your sender reputation, and risk account suspension. Verify your list with StopBouncing before your next campaign — from €0.0006 per email.
No monthly fee · Credits never expire · Data deleted in 48 h
How to verify your Klaviyo list
Four steps. No plugins. No API keys required.
Export your Klaviyo list
In Klaviyo, go to Lists & Segments → select your list → click Export. Download the CSV file with your email addresses.
Upload to StopBouncing
Create a free account and upload your CSV. StopBouncing auto-detects the email column and starts verifying immediately.
Download your clean list
When verification is complete, download your results. Each address is marked Valid, Invalid, Unknown, or Disposable.
Re-import to Klaviyo
Filter for Valid addresses only, then import the clean CSV back into Klaviyo. Your list is now clean and ready to send.
Why Klaviyo users verify with StopBouncing
Protect your Klaviyo deliverability score
Klaviyo penalises accounts with bounce rates above 0.08%. A single list clean before a campaign can keep your account in good standing.
Avoid Klaviyo account suspension
Too many hard bounces can get your Klaviyo account flagged or suspended. Verify before you send to stay within acceptable limits.
Better open rates immediately
Removing undeliverable addresses from your list raises your open rate percentage — a better signal to inbox providers that your content is wanted.
GDPR-safe processing
All uploaded data is automatically deleted within 48 hours. No data stored on third-party ad platforms. Full compliance with EU data protection requirements.
Simple, pay-as-you-go pricing
No monthly subscription. No minimum spend. Pay only for what you verify.
- 10,000 Klaviyo addresses → €6
- 100,000 addresses → €60
- 1,000,000 addresses → €600
- Credits never expire
Frequently asked questions
Does StopBouncing integrate directly with Klaviyo?
StopBouncing works via CSV export and import — the same format Klaviyo uses natively. Export your list from Klaviyo, upload to StopBouncing, then re-import the clean results. No API key or plugin required.
How often should I verify my Klaviyo list?
For active e-commerce lists: before any major campaign (Black Friday, product launches, reactivation flows). For lists with significant new signups: once every 90 days. The older and larger your list, the more critical verification becomes — lists degrade at roughly 22% per year.
Will this remove valid Klaviyo subscribers?
StopBouncing marks addresses as Invalid only when SMTP verification confirms the mailbox does not exist. Addresses that cannot be definitively confirmed are marked Unknown — you keep those. We never remove valid subscribers.
What does verification cost for a typical Klaviyo list?
StopBouncing charges €0.0006 per verification with no monthly fee and no minimum purchase. A 10,000-address Klaviyo list costs €6. A 100,000-address list costs €60. Credits never expire.
Can I use the API instead of CSV upload for Klaviyo?
Yes. If you have a developer on your team, the StopBouncing REST API can verify addresses before they enter Klaviyo — for example, at the point of form submission on your Shopify or custom storefront. This prevents bad addresses from ever entering your Klaviyo account.