Email APIs · side by side
Knock vs Resend
Compare Knock, Resend 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.
Knock
0
Resend
100K
Knock
$0 / mo
Developer · 0 messages
Resend
$90 / mo
Scale · 100K emails
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 | Knock | Resend |
|---|---|---|
| Provider | Knock Labs, Inc. | Resend |
| Billing unit | messages | emails |
| Plan at selected usage | Developer | Scale |
| Monthly estimate | $0/mo | $90/mo |
| Workload | 0 messages | 100K emails |
| Free access | Developer plan includes up to 10,000 messages per month, 500 guide active users, and 500 AI agent credits. | 3,000 emails/mo |
| Published plans | Developer, Starter, Enterprise | Free, Pro, Scale, Enterprise |
| Prices checked | 2026-10-08 | 2026-10-08 |
Provider
- Knock
- Knock Labs, Inc.
- Resend
- Resend
Billing unit
- Knock
- messages
- Resend
- emails
Plan at selected usage
- Knock
- Developer
- Resend
- Scale
Monthly estimate
- Knock
- $0/mo
- Resend
- $90/mo
Workload
- Knock
- 0 messages
- Resend
- 100K emails
Free access
- Knock
- Developer plan includes up to 10,000 messages per month, 500 guide active users, and 500 AI agent credits.
- Resend
- 3,000 emails/mo
Published plans
- Knock
- Developer, Starter, Enterprise
- Resend
- Free, Pro, Scale, Enterprise
Prices checked
- Knock
- 2026-10-08
- Resend
- 2026-10-08
Email APIs monthly cost
Knock: $0Resend: $90
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 | Knock | Resend |
|---|---|---|
| Single sign-on | Not listed | With add-on |
| Messages included | Up to 10,000 Upgrade for additional usage. | Not listed |
| Guide active users included | Up to 500 Upgrade for additional usage. | Not listed |
| AI agent credits included | 500 $.01 per additional credit. | Not listed |
| Notification channels | Unlimited | Not listed |
| Team members | Unlimited | Not listed |
| Recipients | Unlimited | Not listed |
| Power Knock with source events | Not listed | |
| Notification workflows | Unlimited | Not listed |
| Workflow triggers | Unlimited | Not listed |
| 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 | Unlimited | Not listed |
| Pre-built components (In-app feeds) | Not listed | |
| Bring your own components (In-app feeds) | Not listed | |
| Remove Knock branding | Not listed | |
| Feed retention | Unlimited | Not listed |
| Feed API | Not listed | |
| Custom feed filtering | Not listed | |
| Unlimited guides | Unlimited | Not listed |
| 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 | 30-day retention | Not listed |
| 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 | Unlimited | Not listed |
| 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 | 99.9% | Not listed |
| Enterprise support | Not listed | |
| Dedicated infrastructure | Not listed | |
| Daily limit | Not listed | No limit |
| Inbound emails | Not listed | |
| RESTful API | Not listed | |
| SMTP relay | Not listed | |
| Official SDKs | Not listed | |
| Schedule emails | Not listed | |
| Batch sending | Not listed | |
| Open tracking | Not listed | |
| Link tracking | Not listed | |
| React Email | Not listed | |
| Custom domains | Not listed | 1,000 |
| Additional domains | Not listed | With add-on |
| Dedicated IPs | Not listed | With add-on |
| Dedicated IP warming | Not listed | |
| Pristine shared IPs | Not listed | |
| Automatic suppression list | Not listed | |
| Bounce details | Not listed | |
| Multi-region | Not listed | |
| Data retention | Not listed | 30 days |
| Deliverability insights | Not listed | |
| DKIM, SPF, DMARC authentication | Not listed | |
| Webhook endpoints | Not listed | 10 endpoints |
| Webhook events | Not listed | All events |
| Social login | Not listed | |
| GDPR compliance | Not listed | |
| SOC 2 Type II certification | Not listed | |
| Penetration testing | Not listed | |
| DDoS protection | Not listed | |
| Automated backups | Not listed | |
| Multi-factor authentication | Not listed | |
| API key permissions | Not listed | |
| Signed webhook endpoints | Not listed | |
| Ticket support | Not listed | |
| Slack support | Not listed | |
| Urgent response SLA | Not listed | |
| Deliverability expertise | Not listed | |
| In-app documentation | Not listed | |
| AI assistant | Not listed | |
| AI credits / mo | Not listed | 500 |
Single sign-on
- Knock
- Not listed
- Resend
- With add-on
Messages included
- Knock
- Up to 10,000 Upgrade for additional usage.
- Resend
- Not listed
Guide active users included
- Knock
- Up to 500 Upgrade for additional usage.
- Resend
- Not listed
AI agent credits included
- Knock
- 500 $.01 per additional credit.
- Resend
- Not listed
Notification channels
- Knock
- Unlimited
- Resend
- Not listed
Team members
- Knock
- Unlimited
- Resend
- Not listed
Recipients
- Knock
- Unlimited
- Resend
- Not listed
Power Knock with source events
- Knock
- Resend
- Not listed
Notification workflows
- Knock
- Unlimited
- Resend
- Not listed
Workflow triggers
- Knock
- Unlimited
- Resend
- Not listed
Intelligent cross-channel routing
- Knock
- Resend
- Not listed
Batching
- Knock
- Resend
- Not listed
Fetch from HTTP
- Knock
- Resend
- Not listed
Conditional sending
- Knock
- Resend
- Not listed
Scheduled workflows
- Knock
- Resend
- Not listed
Preferences
- Knock
- Resend
- Not listed
End-to-end testing
- Knock
- Resend
- Not listed
Email client previews
- Knock
- Resend
- Not listed
Non-user recipients
- Knock
- Resend
- Not listed
Manage via API & CLI
- Knock
- Resend
- Not listed
Translations (i18n)
- Knock
- Resend
- Not listed
Feeds per recipient
- Knock
- Unlimited
- Resend
- Not listed
Pre-built components (In-app feeds)
- Knock
- Resend
- Not listed
Bring your own components (In-app feeds)
- Knock
- Resend
- Not listed
Remove Knock branding
- Knock
- Resend
- Not listed
Feed retention
- Knock
- Unlimited
- Resend
- Not listed
Feed API
- Knock
- Resend
- Not listed
Custom feed filtering
- Knock
- Resend
- Not listed
Unlimited guides
- Knock
- Unlimited
- Resend
- Not listed
Guide ordering
- Knock
- Resend
- Not listed
Guide throttling
- Knock
- Resend
- Not listed
Pre-built components (In-app guides)
- Knock
- Resend
- Not listed
Bring your own components (In-app guides)
- Knock
- Resend
- Not listed
Per-tenant branding
- Knock
- Resend
- Not listed
Per-tenant preferences
- Knock
- Resend
- Not listed
Logs
- Knock
- Resend
- Not listed
Log retention
- Knock
- 30-day retention
- Resend
- Not listed
Engagement tracking
- Knock
- Resend
- Not listed
Stream observability data
- Knock
- Resend
- Not listed
Stream analytics to Segment
- Knock
- Resend
- Not listed
Stream analytics to data warehouse
- Knock
- Resend
- Not listed
Version control & history
- Knock
- Resend
- Not listed
Isolated environments
- Knock
- Unlimited
- Resend
- Not listed
Custom roles and permissions
- Knock
- Resend
- Not listed
Audit logs
- Knock
- Resend
- Not listed
Google SSO
- Knock
- Resend
- Not listed
Custom SSO
- Knock
- Resend
- Not listed
Directory sync (SCIM)
- Knock
- Resend
- Not listed
Template migration services
- Knock
- Resend
- Not listed
Uptime SLA
- Knock
- 99.9%
- Resend
- Not listed
Enterprise support
- Knock
- Resend
- Not listed
Dedicated infrastructure
- Knock
- Resend
- Not listed
Daily limit
- Knock
- Not listed
- Resend
- No limit
Inbound emails
- Knock
- Not listed
- Resend
RESTful API
- Knock
- Not listed
- Resend
SMTP relay
- Knock
- Not listed
- Resend
Official SDKs
- Knock
- Not listed
- Resend
Schedule emails
- Knock
- Not listed
- Resend
Batch sending
- Knock
- Not listed
- Resend
Open tracking
- Knock
- Not listed
- Resend
Link tracking
- Knock
- Not listed
- Resend
React Email
- Knock
- Not listed
- Resend
Custom domains
- Knock
- Not listed
- Resend
- 1,000
Additional domains
- Knock
- Not listed
- Resend
- With add-on
Dedicated IPs
- Knock
- Not listed
- Resend
- With add-on
Dedicated IP warming
- Knock
- Not listed
- Resend
Pristine shared IPs
- Knock
- Not listed
- Resend
Automatic suppression list
- Knock
- Not listed
- Resend
Bounce details
- Knock
- Not listed
- Resend
Multi-region
- Knock
- Not listed
- Resend
Data retention
- Knock
- Not listed
- Resend
- 30 days
Deliverability insights
- Knock
- Not listed
- Resend
DKIM, SPF, DMARC authentication
- Knock
- Not listed
- Resend
Webhook endpoints
- Knock
- Not listed
- Resend
- 10 endpoints
Webhook events
- Knock
- Not listed
- Resend
- All events
Social login
- Knock
- Not listed
- Resend
GDPR compliance
- Knock
- Not listed
- Resend
SOC 2 Type II certification
- Knock
- Not listed
- Resend
Penetration testing
- Knock
- Not listed
- Resend
DDoS protection
- Knock
- Not listed
- Resend
Automated backups
- Knock
- Not listed
- Resend
Multi-factor authentication
- Knock
- Not listed
- Resend
API key permissions
- Knock
- Not listed
- Resend
Signed webhook endpoints
- Knock
- Not listed
- Resend
Ticket support
- Knock
- Not listed
- Resend
Slack support
- Knock
- Not listed
- Resend
Urgent response SLA
- Knock
- Not listed
- Resend
Deliverability expertise
- Knock
- Not listed
- Resend
In-app documentation
- Knock
- Not listed
- Resend
AI assistant
- Knock
- Not listed
- Resend
AI credits / mo
- Knock
- Not listed
- Resend
- 500
Showing 15 of 91
Which email providers fit your needs?
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
Resend features & plan notes
- React Email
- Simple API
- Webhooks
- All Pro features
- 1,000 domains
- Dedicated Slack channel
- 10 webhook endpoints
- 500 AI credits / mo
- SSO with add-on
- Dedicated IP with add-on
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