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 → | 2 | 3 |
 | 10M–25M | 1st of 10 → | 9 | 33 |
From January 1st to March 31st, Knock routed 100M–500M messages through Mailgun and 10M–25M through Resend. Mailgun reported 3 status page updates over the last 90 days, while Resend reported 33.
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 January 1st to March 31st. The top-line number is an average of these daily values: Mailgun averaged 125ms compared to 78ms for Resend. Mailgun's highest daily p50 was 147ms; Resend's was 118ms. Resend is 47ms 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 182ms compared to 128ms for Resend. The highest daily p90 was 220ms for Mailgun and 175ms for Resend. Resend handles these slower requests 54ms 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 386ms at p99 while Resend reached 354ms. The highest daily p99 was 451ms for Mailgun and 10020ms 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% | 0.03% | Mar 17 | 89 | 1 |
| 0.08% | 2.45% | Feb 15 | 78 | 8 |
Averaged across the date range, Mailgun shows a 0.00% daily error rate compared to 0.08% for Resend. The highest single-day error rate was 0.03% for Mailgun and 2.45% 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 Mar 19, 2026 — Resolved Mar 19, 2026
Mar 19, 11:53 PDT Resolved - A fix has been deployed and systems are back to normal.Mar 19, 11:43 PDT Identified - Some requests may be incorrectly failing with 401 error codes in our US region.
Started Mar 13, 2026 — Resolved Mar 13, 2026
Mar 13, 05:49 PDT Resolved - The incident has been resolved.Mar 13, 05:33 PDT Monitoring - A fix has been implemented and we are monitoring the results.Mar 13, 05:19 PDT Identified - The issue has been identified and a fix is being implemented.Mar 13, 04:56 PDT Update - We are continuing to investigate this issue.Mar 13, 04:29 PDT Investigating - We are currently investigating this issue.
Started Feb 25, 2026 — Resolved Feb 25, 2026
Feb 25, 13:45 PST Resolved - This incident has been resolved.Feb 25, 13:36 PST Monitoring - A fix has been implemented and we are monitoring the results.Feb 25, 12:25 PST Update - We are continuing to work on a fix for this issue.Feb 25, 11:47 PST Update - We are continuing to work on a fix for this issue.Feb 25, 11:30 PST Update - We are continuing to work on a fix for this issue.Feb 25, 11:29 PST Identified - Domain verification is also impacted. Increased chances of domain verification failin
Recent Resend incidents
Recent status page incidents for Resend
Started Mar 28, 2026 — Resolved Mar 28, 2026
Status: Resolved We have resolved the issue causing increased latency in email sending. Emails are being delivered normally. Affected components Single Email (Operational) Broadcast Emails (Operational) Batch Emails (Operational)
Started Mar 26, 2026 — Resolved Mar 26, 2026
Status: Resolved Our systems have caught up and email events are processing normally. No emails were lost or delayed during this time. Affected components Email Events (Operational)
Started Mar 24, 2026 — Resolved Mar 24, 2026
Status: Resolved We have resolved the underlying issue and service has been resumed.
Started Mar 20, 2026 — Resolved Mar 20, 2026
Status: Resolved We have resolved the underlying issue and service has been resumed. Affected components Email Events (Operational)
Started Mar 20, 2026 — Resolved Mar 20, 2026
Status: Complete The maintenance was completed. We're working through some backlogged Email Events. Affected components Dashboard (Operational) Email Events (Operational) General API (Operational) Webhooks (Operational)
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 125ms compared to 78ms for Resend.
Which is more reliable, Mailgun or Resend?
From January 1st to March 31st, Mailgun showed an error rate of 0.00% while Resend showed 0.08%. 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 January 1st to March 31st 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.