Why Success Rate Defines Proxy Quality
Raw speed and pool size matter, but success rate is the metric that separates premium proxy infrastructure from commodity services. A proxy that connects fast but returns blocks, CAPTCHAs, or connection resets 30% of the time costs far more in wasted bandwidth, retry overhead, and delayed data delivery than a slightly slower proxy that succeeds 99% of the time. This calculator turns your raw request logs into a clear success percentage and quantifies the retry penalty.
Computing Your Success Rate
Divide the number of requests that returned a valid 2xx HTTP response by the total number of requests sent, then multiply by 100. If you sent 100,000 requests and 92,000 returned successful responses, your success rate is 92%. The remaining 8,000 requests consumed proxy bandwidth, contributed to per-IP rate limit counts, and delayed your data pipeline without producing any usable output.
The Retry Multiplier Effect
Failed requests rarely disappear quietly. Most scraping frameworks retry each failure 1-3 times. With a 92% success rate and 2 retries per failure, those 8,000 failures generate 16,000 additional requests, inflating your total volume to 116,000 and increasing bandwidth consumption by 16%. On residential proxy plans billed per GB, that retry overhead translates directly into extra cost. On ISP plans with unlimited bandwidth, it still consumes rate limit headroom and extends job duration.
Success Rate Benchmarks by Proxy Type
Hex Proxies ISP proxies from our Ashburn VA facility on owned hardware consistently achieve 98-99.5% success rates across most commercial websites. These IPs are registered to legitimate consumer ISPs (Frontier, Windstream, COX, AT&T, Comcast, Verizon, Charter, RCN), giving them inherent trustworthiness with bot detection systems. Residential proxies through our proprietary network of 10M+ IPs across 150+ countries typically achieve 93-97% success depending on target difficulty. Budget datacenter proxies from other providers often drop below 70% on protected sites.
Diagnosing Low Success Rates
If your success rate falls below 90%, investigate the failure modes. HTTP 403 and 429 responses indicate rate limiting or IP blocking -- rotate IPs faster or increase your pool. Connection timeouts suggest network congestion or unreachable proxies -- check proxy health monitoring. Empty responses or garbled HTML point to JavaScript rendering requirements -- switch to a headless browser integration. Each failure type demands a different remediation strategy.
Using Success Rate to Choose Providers
Run identical test workloads through two or three candidate providers and compare success rates on the same targets. A provider charging $5/GB at 97% success is cheaper per successful request than one charging $3/GB at 75% success. This calculator gives you the core metric for that comparison, and the Cost Per Request Calculator translates it into dollar terms.