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Reading the Report Card

Every completed test produces a Report Card — a single-page graded summary that tells you exactly how your API performed and what to fix.

The overall grade​

Load Curl weighs 8 metrics and produces a letter grade from A to F.

GradeMeaning
AExcellent — all metrics green, ready to scale
BGood — minor latency issues, low production risk
CFair — needs tuning before handling high traffic
DPoor — multiple metrics failing SLA targets
FCritical — server degradation detected, do not ship

The grade is designed to be a single, shareable signal. You can paste a public report link into a pull request or send it to a manager without needing to explain raw numbers.

The 8 graded metrics​

1. P95 Response Time​

The 95th-percentile latency across all requests during the test.

  • Green (A): < 300 ms
  • Yellow (B/C): 300 ms – 1 s
  • Red (D/F): > 1 s

P95 is a better signal than average latency because it captures what your slowest users actually experience. An average of 50 ms is meaningless if 5 % of requests are taking 3 seconds.

2. Error Rate​

The percentage of requests that returned a non-2xx HTTP status code.

  • Green (A): < 0.1 %
  • Yellow (B/C): 0.1 % – 1 %
  • Red (D/F): > 1 %

3. Requests per Second (RPS)​

Peak throughput your API delivered during the test. Higher is better, but this metric is graded relative to your concurrency level — a 50-worker test scoring 400 RPS is proportionally the same as a 1,000-worker test at 8,000 RPS.

4. Throughput​

Total data transferred per second. A sudden drop in throughput mid-test often signals a connection pool exhaustion or a rate limiter kicking in.

5. Server CPU Peak​

The highest CPU utilisation observed on your server during the test. Requires the optional server agent.

  • Green (A): < 70 %
  • Yellow (B/C): 70 % – 90 %
  • Red (D/F): > 90 %

6. Availability​

The percentage of time your server returned any response (including error codes). A value below 99 % usually means the server was completely unreachable for some workers.

7. Latency Stability​

Measures how much latency varied over the test duration. An API that starts at 200 ms and ends at 1,500 ms has poor stability — a sign of a memory leak or connection saturation over time.

8. P99 Response Time​

The 99th-percentile latency. Used as a tiebreaker to distinguish a B+ from an A–. If your P95 is healthy but your P99 is very high, a small percentage of users are experiencing severe delays.

Recommendations panel​

Below the grade, the Report Card shows specific, actionable recommendations for every failing dimension. For example:

⚠ P95 latency exceeds 300 ms target. Consider adding a CDN layer or optimising the database query on /v2/users — 78 % of slow requests originate from a single unindexed join.

Load Curl traces slow requests back to specific endpoints in multi-scenario tests, so you can pinpoint which call in a chain is the bottleneck.

Sharing and exporting​

ActionHow
Share a public linkClick Share → toggle Public link on → copy URL
Export to PDFClick Export → Download PDF (Pro plan and above)
Embed in a PRPaste the public link as a comment; GitHub will render a preview card
Compare to previous runClick Compare → select any prior run from the dropdown

Next step​

Now that you understand your results, learn how to set threshold alerts so you get notified automatically when a key metric degrades.