Mailgun vs Resend
Compare Mailgun and Resend 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) |
|---|---|---|---|---|
| 100M–500M | 5th of 10 → | 3 | 11 |
| 10M–25M | 1st of 10 → | 9 | 9 |
From May 4th to August 2nd, Knock routed 100M–500M messages through Mailgun and 10M–25M through Resend. Mailgun reported 11 status page updates over the last 90 days, while Resend reported 9.
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 May 4th to August 2nd. The top-line number is an average of these daily values: Mailgun averaged 138ms compared to 96ms for Resend. Mailgun's highest daily p50 was 167ms; Resend's was 122ms. Resend is 42ms 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, Mailgun has a p90 of 200ms compared to 168ms for Resend. The highest daily p90 was 8262ms for Mailgun and 221ms for Resend. Resend handles these slower requests 32ms 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, Mailgun reached 603ms at p99 while Resend reached 496ms. The highest daily p99 was 15385ms for Mailgun and 10906ms 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% | 0.04% | Jun 23 | 89 | 2 |
| 0.05% | 3.52% | Jul 29 | 83 | 5 |
Averaged across the date range, Mailgun shows a 0.00% daily error rate compared to 0.05% for Resend. The highest single-day error rate was 0.04% for Mailgun and 3.52% for Resend. Mailgun demonstrates a lower error rate, indicating slightly more consistent availability during this period. 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 Mailgun incidents
Recent status page incidents for Mailgun
Started Jul 24, 2026 — Resolved Jul 24, 2026
Jul 24, 06:49 PDT Resolved - All delayed messages have been processed. Systems are operating normally Jul 24, 06:18 PDT Monitoring - A fix has been implemented and we are monitoring the results. Delayed messages are being processed. Jul 24, 06:16 PDT Update - We are continuing to work on a fix for this issue. Jul 24, 05:38 PDT Identified - The issue has been identified and a fix is being implemented. Jul 24, 05:27 PDT Investigating - Inbound messages processed by routes are currentl
Started Jul 13, 2026 — Resolved Jul 13, 2026
Jul 13, 12:56 PDT Resolved - This incident has been resolved. Jul 13, 12:45 PDT Monitoring - A fix has been implemented and we are monitoring the results. Jul 13, 12:24 PDT Identified - The issue has been identified and a fix is being implemented. Jul 13, 11:51 PDT Update - We are continuing to investigate this issue. Jul 13, 11:23 PDT Investigating - We are currently investigating this issue.
Started Jul 10, 2026 — Resolved Jul 10, 2026
Jul 10, 13:11 PDT Resolved - This incident has been resolved. Jul 10, 12:58 PDT Monitoring - A fix has been implemented and we are monitoring the results. Jul 10, 12:48 PDT Update - A fix is in the process of being rolled out to impacted regions. Jul 10, 12:33 PDT Update - We are continuing to work on a fix for this issue. Jul 10, 11:59 PDT Update - We are continuing to work on a fix for this issue. Jul 10, 11:36 PDT Update - We are continuing to work on a fix for this issue. J
Started Jun 25, 2026 — Resolved Jun 25, 2026
Jun 25, 13:35 PDT Resolved - This incident has been resolved. Jun 25, 13:24 PDT Monitoring - A fix has been implemented and we are monitoring the results. Jun 25, 13:21 PDT Identified - The issue has been identified and a fix is being implemented. Jun 25, 13:03 PDT Update - We are continuing to investigate this issue. Jun 25, 12:21 PDT Investigating - We are currently investigating an issue with email previews not working. Outbound processing, inbound processing, logs and webhook de
Started Jun 23, 2026 — Resolved Jun 23, 2026
Jun 23, 09:09 PDT Resolved - This incident has been resolved. Jun 23, 08:56 PDT Monitoring - A fix has been implemented and we are monitoring the results. Jun 23, 08:25 PDT Update - We are continuing to work on a fix for this issue. Some customers may see log delays. Outbound processing, inbound processing, and webhook delivery continue operating normally. Jun 23, 07:52 PDT Update - We are continuing to work on a fix for this issue. Some customers may see log delays. Outbound processin
Recent Resend incidents
Recent status page incidents for Resend
Started Jul 30, 2026 — Resolved Jul 30, 2026
Status: Resolved We have resolved the underlying issue, and service has resumed. Domain verification has been restored, and affected verifications were re-triggered. Affected components Dashboard (Operational) General API (Operational)
Started Jul 29, 2026 — Resolved Jul 29, 2026
Status: Resolved Between 20:15 and 20:16 UTC, a brief database disruption caused elevated error rates for approximately 45 seconds. During this window, requests to the Resend API, SMTP relay, and dashboard may have returned 5xx errors or timed out. The issue resolved automatically at 20:16 UTC and all services have been operating normally since. Any request that failed during this window can be safely retried. Emails that had already been accepted before the disruption were not lost. They were
Started Jul 29, 2026 — Resolved Jul 29, 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) General API (Operational)
Started Jul 22, 2026 — Resolved Jul 22, 2026
Status: Resolved We have resolved the underlying issue and service has been resumed. Affected components Single Email (Operational) Email Events (Operational) Broadcast Emails (Operational) Website (Operational) Dashboard (Operational) SMTP (Operational) Batch Emails (Operational) General API (Operational) Webhooks (Operational) Automations (Operational)
Started Jul 21, 2026 — Resolved Jul 21, 2026
Status: Resolved Delivery to Microsoft has returned to normal. Thank you for your patience as we worked with them regarding this.
Pros and cons
Mailgun
Resend
Pros
- Well-written documentation with comprehensive guides and best practices for deliverability
- Robust deliverability support with optional expert pairing to optimize sending
- Powerful inbound email processing with customizable routing rules
- Trusted by Lyft, American Express, and Wikipedia since 2010
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
- Requires familiarity with email protocols and API integrations
- Pricing tiers can be confusing
- Email template features are basic without the Mailjet editor
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 the difference between Mailgun and Resend?
Mailgun is a developer-focused email API platform owned by Sinch, known for flexible sending and receiving capabilities. Resend is a modern email API built for developers, with React Email support and a focus on simplicity. Mailgun is best suited for developer-focused sending + receiving, while Resend is geared toward developer-first, react teams.
Which is cheaper, Mailgun or Resend?
Free tier includes 100 emails per day with no expiration. Paid plans start at $15/month for 10,000 emails with overages at $1.80/1K. 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.
Which is faster, Mailgun or Resend?
Based on real-world data from Knock, Mailgun has a median API response time (p50) of 138ms compared to 96ms for Resend.
Which is more reliable, Mailgun or Resend?
From May 4th to August 2nd, Mailgun showed an error rate of 0.00% while Resend showed 0.05%. 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, Mailgun or Resend?
On the Knock platform, Mailgun handled 100M–500M messages from May 4th to August 2nd compared to 10M–25M for Resend. Mailgun volume has remained stable, while Resend volume has remained stable.
Can I use both Mailgun and Resend together?
Yes. Knock enables you to integrate multiple email providers into a single notification workflow. You can use Mailgun and Resend 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 Mailgun vs Resend?
Mailgun strengths include well-written documentation with comprehensive guides and best practices for deliverability and robust deliverability support with optional expert pairing to optimize sending. 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, Mailgun drawbacks include requires familiarity with email protocols and api integrations, while Resend drawbacks include newer and less battle-tested compared to incumbents like mailgun or sendgrid.
Use either provider with Knock
Knock enables you to integrate Mailgun, Resend, or any combination of email providers into a single notification workflow. Manage templates, orchestrate cross-channel delivery, and switch providers without changing your code.