Resend
performance benchmarks
Browse Resend's observed email API response time, error rates, and incident history over the last 90 days.
Live performance metrics
Real-world performance data from messages sent through Knock
| Message volume | Growth | Status page updates (30d) | Status page updates (90d) |
|---|---|---|---|
10M–25M | 1st of 10 → | 12 | 12 |
From May 25th to August 23rd, Knock routed 10M–25M messages through Resend. For adoption, Resend ranks 1st of 10 providers based on new channel connections, with adoption holding steady over the period. Resend reported 12 status page updates over the last 90 days, 12 of which were in the last 30 days.
Response time
Response time measures how long Resend takes to accept an API request from Knock, including connection overhead and any automatic retries. Lower values mean faster message hand-off.
| Median (p50) | p90 | p95 | p99 |
|---|---|---|---|
93ms | 175ms | 238ms | 763ms |
From May 25th to August 23rd, Resend averaged a daily median response time (p50) of 93ms across all days in the range, meaning half of all requests on a typical day complete in under 93ms. The 99th percentile averaged 763ms, with a peak daily p99 of 10906ms. This is slightly higher than some providers, which may reflect additional processing Resend performs on message acceptance.
Error rate
Error rate tracks the ratio of 5xx responses and timeouts to total requests. Knock automatically retries failed requests, so transient provider errors rarely affect end-user delivery.
| Avg. daily error rate | Highest daily rate | Peak error date | Zero-error days | Days above 0.01% |
|---|---|---|---|---|
0.05% | 3.52% | Jul 29 | 80 | 6 |
From May 25th to August 23rd, Resend averaged a 0.05% daily error rate for 5xx responses and timeouts, with the highest single-day error rate reaching 3.52%. This is one of the lowest error rates among providers on Knock, indicating strong reliability and consistent uptime. Knock automatically retries failed requests, so transient provider errors rarely affect end-user delivery.
About these metrics: Data represents messages sent through Knock to Resend during the specified period. Response time measures time from Knock to provider acceptance. Error rate includes only provider 5xx responses and timeouts.
Recent Resend incidents
Recent status page incidents for Resend
Started Aug 20, 2026 — Resolved Aug 20, 2026
Status: Resolved We have resolved the underlying issue and service latency has been recovered. Affected components General API (Operational)
Started Aug 19, 2026 — Resolved Aug 19, 2026
Status: Resolved We have resolved the underlying issue and service has been resumed. Affected components Webhooks (Operational)
Started Aug 16, 2026 — Resolved Aug 16, 2026
Status: Resolved API became unstable from 12:54 to 12:57 UTC, returning 5xx for approximately 7% of the requests. We have resolved the underlying issue and service has been resumed.
Started Aug 13, 2026 — Resolved Aug 13, 2026
Status: Resolved Between approximately 17:30 and 17:43 UTC, requests to add a new domain failed in the dashboard and through the public API (POST /domains). Verification of domains added during this window was also affected. The issue was identified and fixed, and domain creation has returned to normal. No domains were partially created: affected requests failed immediately, so retrying the domain creation will succeed. Email sending for existing domains was not affected. Affected components
Started Aug 9, 2026 — Resolved Aug 9, 2026
Status: Resolved We have resolved the underlying issue and service has been resumed.
Compare Resend with other providers
About Resend
Resend is a modern email API built for developers, with React Email support and a focus on simplicity.
Pros
- Beautiful documentation with attention to detail and great developer experience
- Created and maintain React Email, the go-to framework for building email templates in React
- Minimalist, developer-optimized platform that avoids bloat with a focused UI
- Transparent observability with real-time visibility into sends, failures, and engagement
Cons
- Newer and less battle-tested compared to incumbents like Mailgun or SendGrid
- Fewer enterprise features than established providers
- Limited marketing email capabilities
Frequently asked questions
What is Resend?
Resend is an email service provider commonly used for developer-centric transactional email, react-based email templates, startup and early-stage email delivery. Resend is a modern email API built for developers, with React Email support and a focus on simplicity.
How much does Resend cost?
Free tier includes 3,000 emails per month and 100 emails per day. Paid plans start at $20/month for 50,000 emails with overages at $0.90/1K on Pro, scaling down to $0.46/1K on Scale 2.5M. Resend offers a free tier with up to 3,000 emails, with a hard sending limit on that plan.
How fast is Resend?
Based on real-world data from messages sent through Knock, Resend accepts API requests with a median response time of 93ms (p50) and 763ms at the 99th percentile.
How reliable is Resend?
From May 25th to August 23rd, Resend showed an error rate of 0.05% for 5xx responses and timeouts across 10M–25M messages sent through Knock. Knock automatically retries failed requests, so transient provider errors rarely affect end-user delivery.
What are the pros and cons of Resend?
Key strengths include beautiful documentation with attention to detail and great developer experience and created and maintain react email, the go-to framework for building email templates in react. On the other hand, newer and less battle-tested compared to incumbents like mailgun or sendgrid and fewer enterprise features than established providers.
Does Resend work with Knock?
Yes. Knock has a native Resend integration that enables you to send email notifications through Resend as part of a cross-channel workflow. You can combine Resend with other channels like in-app feeds, push, SMS, and Slack from a single API call.
Use Resend with Knock
Knock enables you to integrate Resend alongside other notification channels, manage templates, and orchestrate cross-channel workflows from a single platform.