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 → | 4 | 13 |
| 10M–25M | 1st of 10 → | 12 | 12 |
From May 24th to August 22nd, Knock routed 100M–500M messages through Mailgun and 10M–25M through Resend. Mailgun reported 13 status page updates over the last 90 days, while Resend reported 12.
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 24th to August 22nd. The top-line number is an average of these daily values: Mailgun averaged 138ms compared to 93ms for Resend. Mailgun's highest daily p50 was 167ms; Resend's was 122ms. Resend is 45ms 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 197ms compared to 174ms for Resend. The highest daily p90 was 8262ms for Mailgun and 334ms for Resend. Resend handles these slower requests 23ms 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 582ms at p99 while Resend reached 761ms. The highest daily p99 was 15385ms for Mailgun and 10906ms for Resend, indicating the worst-case response time during spikes or provider-side congestion. Mailgun 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 | 80 | 6 |
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 Aug 20, 2026 — Resolved Aug 20, 2026
Aug 20, 10:31 PDT Resolved - This incident has been resolved. Aug 20, 10:09 PDT Update - GCP has put a mitigation in place, we are monitoring the results. At this time we are experiencing no impacts. All delayed webhooks and logs have been processed. Aug 20, 09:30 PDT Update - Outbound delivery is operating normally. Currently there are delays for event logs and some webhooks. Aug 20, 09:19 PDT Monitoring - Mailgun is monitoring service impacts in GCP's us-west1 region. We are routing
Started Aug 17, 2026 — Resolved Aug 17, 2026
Aug 17, 13:18 PDT Resolved - We have received confirmation that an external issue impacting email delivery to Microsoft 365 domains has been resolved. Impacted messages would have received an error stating "5.7.511 Access denied, banned sender" between Friday, August 14th and Monday, August 17th. Any failed messages will need to be resent. Information on retrying messages can be found in our Help Center here: https://help.mailgun.com/hc/en-us/articles/18596982041883-Resending-messages
Started Aug 11, 2026 — Resolved Aug 11, 2026
Aug 11, 00:07 PDT Resolved - This incident has been resolved. Aug 10, 23:54 PDT Monitoring - A fix has been implemented and we are monitoring the results. Aug 10, 22:32 PDT Identified - The issue has been identified and a fix is being implemented. Aug 10, 22:32 PDT Investigating - We are currently experiencing a denial of service attack against our click and open tracking servers in our US regions. Remediation work is underway. Some requests may time out or fail at this time.
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.
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.
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 93ms for Resend.
Which is more reliable, Mailgun or Resend?
From May 24th to August 22nd, 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 24th to August 22nd 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.