01 · CAPABILITY
Model realistic API demand
Use requests per second when arrival rate matters, or virtual users when concurrent sessions better reflect the workload. Keep the traffic model consistent across runs so changes are measurable.
API LOAD TESTING
API load testing that goes beyond sending requests.
Validate API latency, throughput, failures, and release capacity with realistic traffic. Run HTTP API load tests from the browser, set pass/fail thresholds, compare results, and move stable checks into CI/CD without maintaining a worker fleet.
FREE TO START · No credit card · HTTP performance testing · Managed execution
TEST DESIGN
What an API test should tell you before release
01Latency budget
Does p95/p99 stay inside the target as throughput rises?
02Failure shape
Which endpoint or dependency bends first?
03Release verdict
Is the new build faster, slower, or simply noisier?
WHY THIS PAGE EXISTS
Turn API performance into a release decision.
A useful API load test answers more than “can this endpoint receive traffic?” It tells you whether the API stays inside an agreed latency and error budget while demand rises, whether authentication and dependent calls remain stable, and whether a new release is slower than the baseline your team already trusts.
02 · CAPABILITY
Test real HTTP flows
Exercise authenticated endpoints, write operations, and multi-step request sequences instead of measuring only a synthetic health endpoint.
03 · CAPABILITY
Fail on thresholds, not opinions
Set p95 latency and failure-rate limits before the run. Auto-stop gives teams a clear safety mechanism when a target is already outside the acceptable envelope.
04 · CAPABILITY
Compare releases
Keep a repeatable scenario and compare current runs against a known baseline. This turns performance from a screenshot into a regression signal.
05 · CAPABILITY
Automate after the test is stable
Move mature checks into CI/CD with API tokens and use alerts, exports, and shared results to keep the outcome visible outside the person who launched the run.
06 · CAPABILITY
Scale without test infrastructure
LoadTester handles distributed execution and worker coordination so the test definition and result stay the team’s focus.
WORKFLOW
Build the API test around the decision you actually need.
Keep the API workload reproducible: pin the endpoint mix, payload shape, authentication method, concurrency model, and thresholds. Scale can change between runs; the API behavior you compare should not.
01
Choose the API path that matters
Start with the endpoint or workflow tied to a real user or business action. Define representative headers, authentication, request bodies, and expected responses.
02
Set the traffic shape
Choose RPS for a controlled arrival rate or VUs for concurrency. Ramp deliberately and avoid jumping straight to destructive traffic.
03
Define pass/fail criteria
Pick a p95 latency target and acceptable error rate before the run. A result is much easier to act on when success was defined in advance.
04
Run, inspect, repeat
Watch latency, throughput, and failures while the test runs. Fix the bottleneck, rerun the same scenario, and keep the comparison meaningful.
05
Promote it into delivery
Once the scenario is stable, trigger it from CI/CD or schedule it as a recurring baseline so regressions are found closer to the change that caused them.
PRODUCT FIT
Built for REST and HTTP API performance checks
Use the same platform for quick endpoint checks, pre-release capacity tests, and recurring performance validation. The free plan is suitable for lightweight API checks; higher-scale and automation features are available when the workflow grows.
10Free VUs
50Free RPS
10kPremium VUs / RPS
IMPLEMENTATION GUIDE
Need the implementation guide?
Read the step-by-step API load testing tutorial for traffic modeling, scenarios, thresholds, metrics, and CI/CD rollout.
Open the supporting guide →OTHER SOLUTIONS
Choose the API scenario that matches the failure you are trying to rule out.
FAQ
API load-testing questions teams ask before the first run.
What is API load testing?
API load testing measures how an HTTP API behaves as request volume or concurrency increases. The useful outputs are latency percentiles, throughput, error rate, and the point where the system leaves its acceptable performance envelope.
Should I test with RPS or virtual users?
Use RPS when you want a controlled request arrival rate. Use virtual users when concurrent sessions and pacing better represent the workload. Many teams use both for different questions.
Can I load test authenticated APIs?
Yes. Build the test around the headers, tokens, payloads, and request sequence your API actually requires. Keep credentials scoped to the test environment and rotate them like any other automation secret.
Can API load tests run in CI/CD?
Yes. After a scenario is stable and fast enough for the pipeline, trigger it through API tokens and use thresholds as a performance gate. Larger tests can remain scheduled or pre-release checks.
Validate the API before the performance question becomes a production incident.
Start with a narrow API scenario on the free plan. Add traffic, regions, or automation only when the release question actually requires them.