SMS API benchmarks
Real-time performance, reliability, and uptime benchmarks for top SMS providers, powered by proprietary data from millions of messages sent through Knock.
Performance at a glance
Sort and filter SMS providers by response time, error rate, and growth.
| Provider | Message volume | Median response time | Error rate | Growth |
|---|---|---|---|---|
 | 100M–500M | 74ms | 0.00% | 1st |
 | 25M–100M | 77ms | 0.00% | 2nd |
 | <1M | 221ms | 0.00% | 5th |
 | <1M | 275ms | 0.42% | 3rd |
 | <1M | 311ms | 0.00% | 7th |
 | <1M | 320ms | 0.16% | 6th |
 | <1M | 720ms | 0.00% | 4th |
 | — | — | — | — |
 | — | — | — | — |
Compare providers
Pick any two providers for a head-to-head comparison of performance, reliability, and pricing.
| Provider | Volume | Median response time | Error rate | Growth |
|---|---|---|---|---|
| Twilio | 100M–500M | 74ms | 0.00% | 1st → |
| Amazon SNS | 25M–100M | 77ms | 0.00% | 2nd → |
Explore provider benchmarks
Explore detailed performance benchmarks, feature comparisons, and pricing for each SMS provider.
Our methodology
How we collect, measure, and present the data behind these benchmarks.
Time range
All metrics reflect a trailing 90-day window. Point-in-time load tests don't capture the variability of a production system handling thousands to millions of requests daily, so we use a longer window to surface the effects of system congestion and public incidents without penalizing providers that are actively improving.
Message volume
Volume represents the total number of sampled SMS API requests routed through Knock during the period. Because Knock is an orchestration layer, we cannot influence the sending patterns of our customers, so volume varies by provider. To normalize for this, we group providers into volume bands that indicate how statistically confident we are in the observed metrics. Providers with low volume are flagged so you can weigh the results accordingly.
Response time
Response time is measured as the elapsed time from when Knock sends an API request to when the provider returns a 200 status indicating message acceptance. We compute percentiles (p50, p90, p95, p99) using exact quantile functions. The measurement includes HTTP connection pooling time and network latency, applied consistently across all providers.
Error rate
Error rate is the ratio of requests that received a 5xx status code to total requests for the period. Knock automatically retries failed requests, so a single request can produce multiple error entries if each retry also fails. We believe this accurately represents the provider's availability during those periods.
Channel growth
In Knock, a connection to a provider API is modeled as a channel. Growth rank reflects how many new channels were created for each provider during the 90-day window. To detect directional trends, we split the window into two 45-day halves and compare them, producing the trend indicators (up, down, or stable) shown alongside each rank.
Frequently asked questions
Which SMS provider has the lowest API response time?
Based on real-world data from 100M–500M messages sent through Knock from January 2nd to April 2nd, Twilio has the lowest median API response time at 74ms (p50). The top three by response time are Twilio (74ms), Amazon SNS (77ms), MessageMedia (221ms).
Which SMS provider is the most reliable?
Amazon SNS currently has the lowest error rate at 0.00% for 5xx responses and timeouts. The top three by reliability are Amazon SNS (0.00%), MessageBird (0.00%), and MessageMedia (0.00%). Knock automatically retries failed requests across all providers.
Which SMS provider is the most popular?
By volume on the Knock platform, Twilio leads with 100M–500M messages from January 2nd to April 2nd. The top three by volume are Twilio (100M–500M), Amazon SNS (25M–100M), MessageMedia (<1M).
Which SMS provider is growing the fastest?
Twilio currently ranks 1st in growth among 7 providers tracked on the Knock platform. The top three fastest-growing providers are Twilio, Amazon SNS, Telnyx.
Can I use multiple SMS providers with Knock?
Yes. Knock enables you to integrate any combination of SMS providers into a single notification workflow. You can route between providers, run migrations, or use different providers for different message types, all without changing your application code.
Use any of these providers with Knock
Knock enables you to integrate any combination of SMS providers into a single notification workflow. Manage templates, orchestrate cross-channel delivery, and switch providers without changing your code.