Email APIs · side by side
Klaviyo vs Reply.io
Compare Klaviyo, Reply.io 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.
Klaviyo
Reply.io
Klaviyo
Custom / not listed
Custom / unlisted usage pricing · 10K profiles
Reply.io
$59 / mo
Email Volume · 0 active contacts
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 | Klaviyo | Reply.io |
|---|---|---|
| Provider | Klaviyo | ReplyApp Inc. |
| Billing unit | profiles | active contacts |
| Plan at selected usage | Custom / unlisted usage pricing | Email Volume |
| Monthly estimate | Custom / not listed | $59/mo |
| Workload | 10K profiles | 0 active contacts |
| Free access | Limited free plan | None (14-day free trial available) |
| Published plans | Free | Email Volume, Multichannel, Agency Core, Agency AI SDR, AI SDR Starter, AI SDR Growth, AI SDR Enterprise, Hybrid plan |
| Prices checked | 2026-10-08 | 2026-10-08 |
- Klaviyo
- Klaviyo
- Reply.io
- ReplyApp Inc.
- Klaviyo
- profiles
- Reply.io
- active contacts
- Klaviyo
- Custom / unlisted usage pricing
- Reply.io
- Email Volume
- Klaviyo
- Custom / not listed
- Reply.io
- $59/mo
- Klaviyo
- 10K profiles
- Reply.io
- 0 active contacts
- Klaviyo
- Limited free plan
- Reply.io
- None (14-day free trial available)
- Klaviyo
- Free
- Reply.io
- Email Volume, Multichannel, Agency Core, Agency AI SDR, AI SDR Starter, AI SDR Growth, AI SDR Enterprise, Hybrid plan
- Klaviyo
- 2026-10-08
- Reply.io
- 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.
Email APIs feature comparison
| Email APIs | Klaviyo | Reply.io |
|---|---|---|
| Active Contacts | Not listed | Starts from 1.000 contacts |
| Mailboxes | Not listed | Unlimited |
| Email warm-ups in Mailtoaster.ai | Not listed | Unlimited |
| LinkedIn automation | Not listed | $69/month per account |
| Calls & SMS | Not listed | $29/month per user |
| Data credits / month | Not listed | 50 included |
| More Data Credits | Not listed | Paid Packages |
| Domain purchase | Not listed | |
| Email search extension | Not listed | |
| Email validation | Not listed | start from $20/month |
| Dialer and Cloud Calls | Not listed | $29/month per user |
| Live Data | Not listed | 50 credits + paid packages |
| Real time B2B data by Generect | Not listed | starting at $39/months |
| Onboarding with the CSM | Not listed | Included on annual |
- Klaviyo
- Not listed
- Reply.io
- Starts from 1.000 contacts
- Klaviyo
- Not listed
- Reply.io
- Unlimited
- Klaviyo
- Not listed
- Reply.io
- Unlimited
- Klaviyo
- Not listed
- Reply.io
- $69/month per account
- Klaviyo
- Not listed
- Reply.io
- $29/month per user
- Klaviyo
- Not listed
- Reply.io
- 50 included
- Klaviyo
- Not listed
- Reply.io
- Paid Packages
- Klaviyo
- Not listed
- Reply.io
- Klaviyo
- Not listed
- Reply.io
- Klaviyo
- Not listed
- Reply.io
- start from $20/month
- Klaviyo
- Not listed
- Reply.io
- $29/month per user
- Klaviyo
- Not listed
- Reply.io
- 50 credits + paid packages
- Klaviyo
- Not listed
- Reply.io
- starting at $39/months
- Klaviyo
- Not listed
- Reply.io
- Included on annual
Which email providers fit your needs?
Klaviyo features & plan notes
- E-commerce data
- Omnichannel
- Shopify ecosystem
Reply.io features & plan notes
- Multichannel sequences across email, LinkedIn, calls, SMS, and WhatsApp
- Unlimited connected mailboxes with automated email warmup
- Autonomous AI SDR agent (Jason AI) for prospecting and meeting booking
- Comprehensive REST API and MCP server support for agentic sales automation
- Email Automation (∞ mailboxes, subject to Fair Usage Policy)
- LinkedIn Automation ($69 /mo/acct)
- Calls & SMS Automation ($29 /mo/acct)
- Email warm-up (Included with every mailbox)
- Unlimited emails
- 50 Live data credits/month
- Anti-spam & deliverability suite
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