Resend vs SendGrid
Compare Resend and SendGrid based on observed API performance, features, and pricing
Live performance comparison
Real-world performance data from messages sent through Knock
| Provider | Message volume | Growth | Status page updates (30d) | Status page updates (90d) |
|---|---|---|---|---|
| 10M–25M | 1st of 10 → | 5 | 20 |
| 500M+ | 2nd of 10 → | 9 | 25 |
From March 3rd to June 1st, Knock routed 10M–25M messages through Resend and 500M+ through SendGrid. Resend reported 20 status page updates over the last 90 days, while SendGrid reported 25.
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.
The chart above shows each provider's daily median response time (p50) from March 3rd to June 1st. The top-line number is an average of these daily values: Resend averaged 88ms compared to 23ms for SendGrid. Resend's highest daily p50 was 118ms; SendGrid's was 24ms. SendGrid is 65ms 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, Resend has a p90 of 148ms compared to 76ms for SendGrid. The highest daily p90 was 192ms for Resend and 86ms for SendGrid. SendGrid handles these slower requests 72ms 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, Resend reached 363ms at p99 while SendGrid reached 386ms. The highest daily p99 was 1410ms for Resend and 4037ms for SendGrid, indicating the worst-case response time during spikes or provider-side congestion. Both providers exhibit comparable tail response times, meaning neither is significantly more prone to outlier slowdowns.
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% |
|---|---|---|---|---|---|
| 0.03% | 2.02% | Mar 20 | 84 | 4 |
| 0.00% | 0.02% | Mar 24 | 87 | 2 |
Averaged across the date range, Resend shows a 0.03% daily error rate compared to 0.00% for SendGrid. The highest single-day error rate was 2.02% for Resend and 0.02% for SendGrid. 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 Resend incidents
Recent status page incidents for Resend
Started May 26, 2026 — Resolved May 26, 2026
Status: Resolved We have resolved the underlying issue and service has been resumed. Affected components Broadcast Emails (Operational) Website (Operational) Single Email (Operational) Dashboard (Operational) Email Events (Operational) SMTP (Operational) Batch Emails (Operational) General API (Operational) Webhooks (Operational)
Started May 20, 2026 — Resolved May 20, 2026
Status: Complete We've completed our Email Events maintenance, and they are now showing the up-to-date status. Affected components Email Events (Operational)
Started May 8, 2026 — Resolved May 8, 2026
Status: Resolved We have resolved the underlying issue by reverting the unintended breaking change and service has been resumed. Affected components Dashboard (Operational) Batch Emails (Operational) General API (Operational) Single Email (Operational) Email Events (Operational) SMTP (Operational) Broadcast Emails (Operational) Webhooks (Operational) Website (Operational)
Started May 6, 2026 — Resolved May 6, 2026
Status: Resolved This incident is resolved. All failed provisioning requests have been reprocessed, and custom tracking domain creation is operating normally.
Started May 5, 2026 — Resolved May 5, 2026
Status: Complete We've successfully completed our maintenance, and the logs page is now behaving normally. Affected components Dashboard (Operational)
Recent SendGrid incidents
Recent status page incidents for SendGrid
Started May 29, 2026 — Resolved May 29, 2026
May 29, 07:30 PDT Resolved - Customers have experienced elevated latency occurring in US East region from 6:30 AM to 8:58 AM Pacific time. Our engineers have investigated and resolved the issue. All impacted services are operating normally.
Started May 22, 2026 — Resolved May 22, 2026
May 22, 11:50 PDT Resolved - Our engineers have monitored the fix and confirmed the issue with SenderAuth and Whitelabel domains has been resolved. All services are now operating normally at this time. May 22, 10:51 PDT Monitoring - Our engineers have implemented a fix and are monitoring system performance. We will provide another update in an hour or as soon as more information becomes available. May 22, 10:30 PDT Investigating - Starting around 10:17AM on May 22 2026, our engineers bega
Started May 14, 2026 — Resolved May 14, 2026
May 14, 10:47 PDT Resolved - Our engineers have monitored the fix and confirmed the issue with Sender Engagement Quality (SEQ) API endpoint has been resolved. All services are now operating normally at this time. May 14, 10:12 PDT Monitoring - Our engineers have implemented a fix and are monitoring system performance. SendGrid Engagement Quality API endpoint is now working as expected with API keys. We will provide another update in 30 minutes or as soon as more information becomes available
Started May 13, 2026 — Resolved May 13, 2026
May 13, 08:30 PDT Resolved - Customers in US-East may have experienced intermittent high mail send latency from 5/13/2026 to 5/27/2026. Our engineers have investigated and resolved the issue. All impacted services are operating normally.
Started May 13, 2026 — Resolved May 13, 2026
May 12, 17:22 PDT Resolved - Our engineers have monitored the fix and confirmed all services are now operating normally. May 12, 16:48 PDT Monitoring - Between 16:10 PDT and 16:27 PDT on 05/12/2026, our engineers began investigating an issue with a subset of services experiencing 5xx errors. Users may have experienced issues when accessing subusers, authenticating domains and link branding records, accessing the account, and checking account stats. This does not impact mail send. Our eng
Pros and cons
Resend
SendGrid
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
Pros
- Comprehensive documentation with SDKs for most major languages
- Rich analytics tools with programmatic API access to engagement data
- Strong focus on deliverability with AI-powered intelligent delivery
- Trusted by Uber, Booking.com, and Yelp for high-volume sending
Cons
- Newer and less battle-tested compared to incumbents like Mailgun or SendGrid
- Fewer enterprise features than established providers
- Limited marketing email capabilities
Cons
- Extended email activity history requires a paid add-on
- Pricing can become complex at higher volumes
- Support response times vary by plan tier
Frequently asked questions
What is the difference between Resend and SendGrid?
Resend is a modern email API built for developers, with React Email support and a focus on simplicity. SendGrid is a cloud-based email delivery platform owned by Twilio, known for high-volume transactional and marketing email. Resend is best suited for developer-first, react teams, while SendGrid is geared toward high-volume transactional + marketing.
Which is cheaper, Resend or SendGrid?
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. Free tier includes up to 100 emails per day for 60 days. Paid plans start at $19.95/month for 50,000 emails on the Essentials plan, with an Essentials 100K tier at $34.95/month. Pro plans with dedicated IPs start at $249/month for 300,000 emails. The best value depends on your sending volume. Use the pricing calculator above to compare costs at your expected volume.
Which is faster, Resend or SendGrid?
Based on real-world data from Knock, Resend has a median API response time (p50) of 88ms compared to 23ms for SendGrid.
Which is more reliable, Resend or SendGrid?
From March 3rd to June 1st, Resend showed an error rate of 0.03% while SendGrid 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.
Which is more popular, Resend or SendGrid?
On the Knock platform, Resend handled 10M–25M messages from March 3rd to June 1st compared to 500M+ for SendGrid. Resend volume has remained stable, while SendGrid volume has remained stable.
Can I use both Resend and SendGrid together?
Yes. Knock enables you to integrate multiple email providers into a single notification workflow. You can use Resend and SendGrid side by side, route traffic between them, or migrate from one to the other without changing your application code.
What are the main pros and cons of Resend vs SendGrid?
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. SendGrid strengths include comprehensive documentation with sdks for most major languages and rich analytics tools with programmatic api access to engagement data. On the other hand, Resend drawbacks include newer and less battle-tested compared to incumbents like mailgun or sendgrid, while SendGrid drawbacks include extended email activity history requires a paid add-on.
Use either provider with Knock
Knock enables you to integrate Resend, SendGrid, or any combination of email providers into a single notification workflow. Manage templates, orchestrate cross-channel delivery, and switch providers without changing your code.