Email APIs · side by side
Klaviyo vs Knock
Compare Klaviyo, Knock 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
10K
Knock
0
Klaviyo
Custom / not listed
Custom / unlisted usage pricing · 10K profiles
Knock
$0 / mo
Developer · 0 messages
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 | Knock |
|---|---|---|
| Provider | Klaviyo | Knock Labs, Inc. |
| Billing unit | profiles | messages |
| Plan at selected usage | Custom / unlisted usage pricing | Developer |
| Monthly estimate | Custom / not listed | $0/mo |
| Workload | 10K profiles | 0 messages |
| Free access | Limited free plan | Developer plan includes up to 10,000 messages per month, 500 guide active users, and 500 AI agent credits. |
| Published plans | Free | Developer, Starter, Enterprise |
| Prices checked | 2026-10-08 | 2026-10-08 |
Provider
- Klaviyo
- Klaviyo
- Knock
- Knock Labs, Inc.
Billing unit
- Klaviyo
- profiles
- Knock
- messages
Plan at selected usage
- Klaviyo
- Custom / unlisted usage pricing
- Knock
- Developer
Monthly estimate
- Klaviyo
- Custom / not listed
- Knock
- $0/mo
Workload
- Klaviyo
- 10K profiles
- Knock
- 0 messages
Free access
- Klaviyo
- Limited free plan
- Knock
- Developer plan includes up to 10,000 messages per month, 500 guide active users, and 500 AI agent credits.
Published plans
- Klaviyo
- Free
- Knock
- Developer, Starter, Enterprise
Prices checked
- Klaviyo
- 2026-10-08
- Knock
- 2026-10-08
Email APIs monthly cost
Klaviyo: Not pricedKnock: $0
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 | Knock |
|---|---|---|
| Messages included | Not listed | Up to 10,000 Upgrade for additional usage. |
| Guide active users included | Not listed | Up to 500 Upgrade for additional usage. |
| AI agent credits included | Not listed | 500 $.01 per additional credit. |
| Notification channels | Not listed | Unlimited |
| Team members | Not listed | Unlimited |
| Recipients | Not listed | Unlimited |
| Power Knock with source events | Not listed | |
| Notification workflows | Not listed | Unlimited |
| Workflow triggers | Not listed | Unlimited |
| Intelligent cross-channel routing | Not listed | |
| Batching | Not listed | |
| Fetch from HTTP | Not listed | |
| Conditional sending | Not listed | |
| Scheduled workflows | Not listed | |
| Preferences | Not listed | |
| End-to-end testing | Not listed | |
| Email client previews | Not listed | |
| Non-user recipients | Not listed | |
| Manage via API & CLI | Not listed | |
| Translations (i18n) | Not listed | |
| Feeds per recipient | Not listed | Unlimited |
| Pre-built components (In-app feeds) | Not listed | |
| Bring your own components (In-app feeds) | Not listed | |
| Remove Knock branding | Not listed | |
| Feed retention | Not listed | Unlimited |
| Feed API | Not listed | |
| Custom feed filtering | Not listed | |
| Unlimited guides | Not listed | Unlimited |
| Guide ordering | Not listed | |
| Guide throttling | Not listed | |
| Pre-built components (In-app guides) | Not listed | |
| Bring your own components (In-app guides) | Not listed | |
| Per-tenant branding | Not listed | |
| Per-tenant preferences | Not listed | |
| Logs | Not listed | |
| Log retention | Not listed | 30-day retention |
| Engagement tracking | Not listed | |
| Stream observability data | Not listed | |
| Stream analytics to Segment | Not listed | |
| Stream analytics to data warehouse | Not listed | |
| Version control & history | Not listed | |
| Isolated environments | Not listed | Unlimited |
| Custom roles and permissions | Not listed | |
| Audit logs | Not listed | |
| Google SSO | Not listed | |
| Custom SSO | Not listed | |
| Directory sync (SCIM) | Not listed | |
| Template migration services | Not listed | |
| Uptime SLA | Not listed | 99.9% |
| Enterprise support | Not listed | |
| Dedicated infrastructure | Not listed |
Messages included
- Klaviyo
- Not listed
- Knock
- Up to 10,000 Upgrade for additional usage.
Guide active users included
- Klaviyo
- Not listed
- Knock
- Up to 500 Upgrade for additional usage.
AI agent credits included
- Klaviyo
- Not listed
- Knock
- 500 $.01 per additional credit.
Notification channels
- Klaviyo
- Not listed
- Knock
- Unlimited
Team members
- Klaviyo
- Not listed
- Knock
- Unlimited
Recipients
- Klaviyo
- Not listed
- Knock
- Unlimited
Power Knock with source events
- Klaviyo
- Not listed
- Knock
Notification workflows
- Klaviyo
- Not listed
- Knock
- Unlimited
Workflow triggers
- Klaviyo
- Not listed
- Knock
- Unlimited
Intelligent cross-channel routing
- Klaviyo
- Not listed
- Knock
Batching
- Klaviyo
- Not listed
- Knock
Fetch from HTTP
- Klaviyo
- Not listed
- Knock
Conditional sending
- Klaviyo
- Not listed
- Knock
Scheduled workflows
- Klaviyo
- Not listed
- Knock
Preferences
- Klaviyo
- Not listed
- Knock
End-to-end testing
- Klaviyo
- Not listed
- Knock
Email client previews
- Klaviyo
- Not listed
- Knock
Non-user recipients
- Klaviyo
- Not listed
- Knock
Manage via API & CLI
- Klaviyo
- Not listed
- Knock
Translations (i18n)
- Klaviyo
- Not listed
- Knock
Feeds per recipient
- Klaviyo
- Not listed
- Knock
- Unlimited
Pre-built components (In-app feeds)
- Klaviyo
- Not listed
- Knock
Bring your own components (In-app feeds)
- Klaviyo
- Not listed
- Knock
Remove Knock branding
- Klaviyo
- Not listed
- Knock
Feed retention
- Klaviyo
- Not listed
- Knock
- Unlimited
Feed API
- Klaviyo
- Not listed
- Knock
Custom feed filtering
- Klaviyo
- Not listed
- Knock
Unlimited guides
- Klaviyo
- Not listed
- Knock
- Unlimited
Guide ordering
- Klaviyo
- Not listed
- Knock
Guide throttling
- Klaviyo
- Not listed
- Knock
Pre-built components (In-app guides)
- Klaviyo
- Not listed
- Knock
Bring your own components (In-app guides)
- Klaviyo
- Not listed
- Knock
Per-tenant branding
- Klaviyo
- Not listed
- Knock
Per-tenant preferences
- Klaviyo
- Not listed
- Knock
Logs
- Klaviyo
- Not listed
- Knock
Log retention
- Klaviyo
- Not listed
- Knock
- 30-day retention
Engagement tracking
- Klaviyo
- Not listed
- Knock
Stream observability data
- Klaviyo
- Not listed
- Knock
Stream analytics to Segment
- Klaviyo
- Not listed
- Knock
Stream analytics to data warehouse
- Klaviyo
- Not listed
- Knock
Version control & history
- Klaviyo
- Not listed
- Knock
Isolated environments
- Klaviyo
- Not listed
- Knock
- Unlimited
Custom roles and permissions
- Klaviyo
- Not listed
- Knock
Audit logs
- Klaviyo
- Not listed
- Knock
Google SSO
- Klaviyo
- Not listed
- Knock
Custom SSO
- Klaviyo
- Not listed
- Knock
Directory sync (SCIM)
- Klaviyo
- Not listed
- Knock
Template migration services
- Klaviyo
- Not listed
- Knock
Uptime SLA
- Klaviyo
- Not listed
- Knock
- 99.9%
Enterprise support
- Klaviyo
- Not listed
- Knock
Dedicated infrastructure
- Klaviyo
- Not listed
- Knock
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Which email providers fit your needs?
Klaviyo features & plan notes
- E-commerce data
- Omnichannel
- Shopify ecosystem
Knock features & plan notes
- Cross-channel workflow orchestration with batching, delays, and branch logic
- Prebuilt and headless UI components for in-app notification feeds
- Out-of-the-box user preference management and hosted preference centers
- Git-like commit and workflow promotion across environments with CLI and API support
- 10K messages (Includes messages sent from workflows and broadcasts)
- 500 guide active users (A user that sees at least one guide in the month)
- 500 AI agent credits (Credits consumed by AI agent function, then $.01 per credit)
- Unlimited notification workflows
- Unlimited broadcasts
- Unlimited delivery channels
- Unlimited team members
- Batch and delay notifications
- Built-in multi-tenancy
- SSO via Google
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