Email APIs · side by side
Apollo.io vs Klaviyo
Compare Apollo.io, Klaviyo by sending volume, delivery webhooks, inbound email, domain limits and retention.
Email APIs pricing calculator
These providers bill in different units. Each estimate uses its own workload; there is no same-volume price winner.
Apollo.io
Klaviyo
Apollo.io
$0 / mo
Free · 0 user
Klaviyo
Custom / not listed
Custom / unlisted usage pricing · 10K profiles
Listed USD plan fees and tracked usage only. Unlisted compute, transfer, extras, taxes and contract terms are excluded. Custom or unsupported plan usage is not estimated.
Email APIs overview & pricing
| Email APIs | Apollo.io | Klaviyo |
|---|---|---|
| Provider | Apollo.io, Inc. | Klaviyo |
| Billing unit | user | profiles |
| Plan at selected usage | Free | Custom / unlisted usage pricing |
| Monthly estimate | $0/mo | Custom / not listed |
| Workload | 0 user | 10K profiles |
| Free access | Free plan includes up to 10,000 email credits per month, limited mobile and export credits, basic filters, and 2 active | Limited free plan |
| Published plans | Free, Basic, Professional, Custom | Free |
| Prices checked | 2026-10-08 | 2026-10-08 |
- Apollo.io
- Apollo.io, Inc.
- Klaviyo
- Klaviyo
- Apollo.io
- user
- Klaviyo
- profiles
- Apollo.io
- Free
- Klaviyo
- Custom / unlisted usage pricing
- Apollo.io
- $0/mo
- Klaviyo
- Custom / not listed
- Apollo.io
- 0 user
- Klaviyo
- 10K profiles
- Apollo.io
- Free plan includes up to 10,000 email credits per month, limited mobile and export credits, basic filters, and 2 active
- Klaviyo
- Limited free plan
- Apollo.io
- Free, Basic, Professional, Custom
- Klaviyo
- Free
- Apollo.io
- 2026-10-08
- Klaviyo
- 2026-10-08
Email APIs monthly cost
Different workloads, separate estimates
Separate transactional delivery from campaigns, outreach and agent inboxes. Compare monthly sends and daily caps; contacts, seats and inboxes are not sending allowances. Budget separately for dedicated IPs, validation and attachments.
Which email providers fit your needs?
Apollo.io features & plan notes
- Database of over 275 million B2B contacts with verified email addresses
- Automated multi-step email sequences and engagement cadences
- Chrome extension for lead enrichment and prospecting directly from LinkedIn
- Native CRM integrations with platforms like Salesforce and HubSpot
- Connect Gmail accounts only
- Email campaigns included
- Unlimited email addresses for contacts (subject to Fair Use Policy)
Klaviyo features & plan notes
- E-commerce data
- Omnichannel
- Shopify ecosystem
How to compare email providers
Separate transactional delivery from campaigns, outreach and agent inboxes. Compare monthly sends and daily caps; contacts, seats and inboxes are not sending allowances. Budget separately for dedicated IPs, validation and attachments.
Browse Email APIs pricing