Compare Amazon SES against Resend API performance
Compare real-time performance, reliability, and uptime benchmarks for Amazon SES and Resend, powered by proprietary data from billions of messages sent through Knock.
Live performance comparison
Real-world performance data from messages sent through Knock.
| Provider | Message volume | Growth | Status page updates (30d) | Status page updates (90d) |
|---|---|---|---|---|
 | 100M–500M | 3rd of 10 → | 0 | 0 |
 | 10M–25M | 1st of 10 → | 2 | 2 |
From August 13th to November 11th, Knock routed 100M–500M messages through Amazon SES and 10M–25M through Resend. Amazon SES reported 0 status page updates over the last 90 days, while Resend reported 2.
Response time
Response time measures how long each provider takes to accept an API request from Knock, including connection overhead and any automatic retries. Lower values mean faster message hand-off.
| Provider | Median (p50) | p90 | p95 | p99 |
|---|---|---|---|---|
| 168ms | 248ms | 311ms | 449ms |
| 70ms | 102ms | 122ms | 304ms |
The chart above shows each provider's daily median response time (p50) from August 13th to November 11th. The top-line number is an average of these daily values: Amazon SES averaged 168ms compared to 70ms for Resend. Amazon SES's highest daily p50 was 183ms; Resend's was 96ms. Resend is 98ms faster at the median, which can add up at high volumes.
The 90th percentile (p90) captures the slowest 10% of requests, revealing how each provider handles moderate stress. Averaged across all days, Amazon SES has a p90 of 248ms compared to 102ms for Resend. The highest daily p90 was 311ms for Amazon SES and 146ms for Resend. Resend handles these slower requests 146ms faster, suggesting more consistent performance across the board.
The 99th percentile (p99) represents the long tail — the slowest 1% of requests. Averaged across all days, Amazon SES reached 449ms at p99 while Resend reached 304ms. The highest daily p99 was 553ms for Amazon SES and 1793ms for Resend, indicating the worst-case response time during spikes or provider-side congestion. Resend shows a tighter tail, which may matter for time-sensitive notifications like one-time passwords or real-time alerts where even rare delays can impact user experience.
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.
| Provider | Avg. daily error rate | Highest daily rate | Peak error date | Zero-error days | Days above 0.01% |
|---|---|---|---|---|---|
| 0.00% | 0.00% | Aug 13 | 91 | 0 |
| 0.00% | 0.09% | Oct 1 | 89 | 2 |
Averaged across the date range, Amazon SES shows a 0.00% daily error rate compared to 0.00% for Resend. The highest single-day error rate was 0.00% for Amazon SES and 0.09% for Resend. Both providers show similar reliability levels, with error rates well within acceptable thresholds. Knock automatically retries failed requests to both providers, minimizing the impact of transient errors on end-user delivery.
About these metrics: Data represents messages sent through Knock during the specified period. Response time measures time from Knock to provider acceptance. Error rate includes only provider 5xx responses and timeouts.
Recent Amazon SES incidents
Recent status page incidents for Amazon SES
No incidents reported in the last 90 days
Recent Resend incidents
Recent status page incidents for Resend
Started Oct 26, 2026 — Resolved Oct 26, 2026
Status: Resolved Email status updates are processing normally again. All delayed updates have been delivered, and no data was lost. Affected components Email Events (Operational)
Started Oct 23, 2026 — Resolved Oct 23, 2026
Status: Resolved We have resolved the underlying issue and service has been resumed. Affected components Single Email (Operational) Broadcast Emails (Operational) Batch Emails (Operational) Scheduled Emails (Operational)
Pros and cons
Compare the strengths and tradeoffs between Amazon SES and Resend.
Amazon SES
Pros
- Delivers billions of emails per year for Netflix, Reddit, and Amazon
- Lowest cost per email among major providers with simple pay-as-you-go pricing
- Deep integration with the AWS ecosystem and SDKs in all major languages
- Highly scalable with no sending limits after warmup
Cons
- Setup is complex with documentation that can be difficult to navigate
- New accounts are sandboxed to 200 messages per 24-hour period
- Accessing analytics requires additional AWS services like SNS and Lambda
Resend
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
Pricing comparison
Compare Amazon SES and Resend as your email volume grows.
Frequently asked questions
Amazon SES is a cost-effective, cloud-scale email service built on AWS infrastructure. Resend is a modern email API built for developers, with React Email support and a focus on simplicity. Amazon SES is best suited for cost-sensitive, high-volume, while Resend is geared toward developer-first, react teams.
3,000 free emails per month for the first 12 months. After that, $0.10 per 1,000 emails with additional charges for attachments and dedicated IPs. 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. The best value depends on your sending volume. Use the pricing calculator above to compare costs at your expected volume.
Based on real-world data from Knock, Amazon SES has a median API response time (p50) of 168ms compared to 70ms for Resend.
From August 13th to November 11th, Amazon SES showed an error rate of 0.00% while Resend showed 0.00%. Both rates are within acceptable thresholds for production email delivery, and Knock automatically retries failed requests to minimize the impact of transient errors.
On the Knock platform, Amazon SES handled 100M–500M messages from August 13th to November 11th compared to 10M–25M for Resend. Amazon SES volume has remained stable, while Resend volume has remained stable.
Yes. Knock enables you to integrate multiple email providers into a single notification workflow. You can use Amazon SES and Resend side by side, route traffic between them, or migrate from one to the other without changing your application code.
Amazon SES strengths include delivers billions of emails per year for netflix, reddit, and amazon and lowest cost per email among major providers with simple pay-as-you-go pricing. Resend 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, Amazon SES drawbacks include setup is complex with documentation that can be difficult to navigate, while Resend drawbacks include newer and less battle-tested compared to incumbents like mailgun or sendgrid.