Compare Mandrill against SendGrid API performance
Compare real-time performance, reliability, and uptime benchmarks for Mandrill and SendGrid, 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) |
|---|---|---|---|---|
 | <1M | 7th of 10 → | 0 | 0 |
 | 100M–500M | 2nd of 10 → | 25 | 25 |
From August 13th to November 11th, Knock routed <1M messages through Mandrill and 100M–500M through SendGrid. Mandrill reported 0 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 August 13th to November 11th. The top-line number is an average of these daily values: Mandrill averaged 299ms compared to 14ms for SendGrid. Mandrill's highest daily p50 was 378ms; SendGrid's was 26ms. SendGrid is 285ms 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, Mandrill has a p90 of 605ms compared to 33ms for SendGrid. The highest daily p90 was 827ms for Mandrill and 37ms for SendGrid. SendGrid handles these slower requests 572ms 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, Mandrill reached 1466ms at p99 while SendGrid reached 99ms. The highest daily p99 was 1980ms for Mandrill and 138ms for SendGrid, indicating the worst-case response time during spikes or provider-side congestion. SendGrid 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% | 0.08% | Sep 15 | 88 | 3 |
| 0.00% | 0.00% | Aug 13 | 91 | 0 |
Averaged across the date range, Mandrill shows a 0.00% daily error rate compared to 0.00% for SendGrid. The highest single-day error rate was 0.08% for Mandrill and 0.00% 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 Mandrill incidents
Recent status page incidents for Mandrill
No incidents reported in the last 90 days
Recent SendGrid incidents
Recent status page incidents for SendGrid
Ongoing since Dec 23, 2026
THIS IS A SCHEDULED EVENT Dec 22, 20:00 PST - Dec 23, 00:00 PST Nov 6, 10:27 PST Scheduled - Twilio is conducting a planned maintenance from 22 December 2026 at 20:00 PST until 23 December 2026 at 00:00 PST. During the maintenance window, there could be intermittent delays or failures delivering SMS and MMS to and from United States and Canada handsets when sending via subset of long codes, short codes and toll free numbers.
Ongoing since Dec 17, 2026
THIS IS A SCHEDULED EVENT Dec 16, 20:00 PST - Dec 17, 00:00 PST Nov 6, 10:27 PST Scheduled - Twilio is conducting a planned maintenance from 16 December 2026 at 20:00 PST until 17 December 2026 at 00:00 PST. During the maintenance window, there could be intermittent delays or failures delivering SMS and MMS to and from United States and Canada handsets when sending via subset of long codes, short codes and toll free numbers.
Ongoing since Dec 10, 2026
THIS IS A SCHEDULED EVENT Dec 9, 20:00 PST - Dec 10, 00:00 PST Nov 6, 10:26 PST Scheduled - Twilio is conducting a planned maintenance from 09 December 2026 at 20:00 PST until 10 December 2026 at 00:00 PST. During the maintenance window, there could be intermittent delays or failures delivering SMS and MMS to and from United States and Canada handsets when sending via subset of long codes, short codes and toll free numbers.
Ongoing since Dec 3, 2026
THIS IS A SCHEDULED EVENT Dec 2, 20:00 PST - Dec 3, 00:00 PST Nov 6, 10:26 PST Scheduled - Twilio is conducting a planned maintenance from 02 December 2026 at 20:00 PST until 03 December 2026 at 00:00 PST. During the maintenance window, there could be intermittent delays or failures delivering SMS and MMS to and from United States and Canada handsets when sending via subset of long codes, short codes and toll free numbers.
Ongoing since Nov 29, 2026
THIS IS A SCHEDULED EVENT Nov 29, 11:00 - 13:00 PST Oct 29, 03:34 PDT Scheduled - The Globe Telecom network in the Philippines is conducting a planned maintenance from 29 November 2026 at 11:00 PST until 29 November 2026 at 13:00 PST. During the maintenance window, there could be intermittent delays delivering SMS to Globe Telecom Philippines handsets.
Pros and cons
Compare the strengths and tradeoffs between Mandrill and SendGrid.
Mandrill
Pros
- Friendly, well-laid-out developer documentation that makes integration straightforward
- Global infrastructure for fast delivery with dedicated IPs and IP address pools
- Solid analytics with reports on deliverability, opens, clicks, bounces, and rejections
- Reuse Mailchimp templates for transactional email with deep ecosystem integration
Cons
- Requires an existing Mailchimp Standard or Premium subscription
- Not available as a standalone service
- Higher cost than some dedicated transactional services
SendGrid
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
- Extended email activity history requires a paid add-on
- Pricing can become complex at higher volumes
- Support response times vary by plan tier
Pricing comparison
Compare Mandrill and SendGrid as your email volume grows.
Frequently asked questions
Mandrill is a transactional email add-on for Mailchimp, suited for teams already using the Mailchimp platform. SendGrid is a cloud-based email delivery platform owned by Twilio, known for high-volume transactional and marketing email. Mandrill is best suited for mailchimp users needing transactional, while SendGrid is geared toward high-volume transactional + marketing.
Included as an add-on to Mailchimp Standard or Premium plans. Pricing is based on email blocks of 25,000 emails, starting at $20/block. Volume discounts apply: $18/block above 500K, scaling down to $10/block above 4M. 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.
Based on real-world data from Knock, Mandrill has a median API response time (p50) of 299ms compared to 14ms for SendGrid.
From August 13th to November 11th, Mandrill showed an error rate of 0.00% 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.
On the Knock platform, Mandrill handled <1M messages from August 13th to November 11th compared to 100M–500M for SendGrid. Mandrill volume has remained stable, while SendGrid volume has remained stable.
Yes. Knock enables you to integrate multiple email providers into a single notification workflow. You can use Mandrill and SendGrid side by side, route traffic between them, or migrate from one to the other without changing your application code.
Mandrill strengths include friendly, well-laid-out developer documentation that makes integration straightforward and global infrastructure for fast delivery with dedicated ips and ip address pools. 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, Mandrill drawbacks include requires an existing mailchimp standard or premium subscription, while SendGrid drawbacks include extended email activity history requires a paid add-on.