
What k6 Can’t Test, Keploy Cancatch what breaks
Open Source Load Testing by Grafana Labs
Keploy auto-generates functional API tests from real traffic using eBPF, while k6 is an open-source load testing tool for writing performance tests in JavaScript. Keploy focuses on API correctness and regression detection, whereas k6 measures performance under load with configurable virtual user scenarios and Grafana integration.
How Keploy turns real traffic into a test suite
One pipeline, running the moment your app receives a request. No SDKs, no sidecars, no test scripts — just kernel-level capture that becomes deterministic regression coverage.
- 01Real API trafficLive requests + responses from your running app
- 02eBPF captureKernel-level recording — zero code changes
- 03NormalizeTime-freeze + field noise removed automatically
- 04Generate testsDeterministic test cases from actual behavior
- 05Generate mocksEvery downstream dependency stubbed for you
- 06Replay in CIRuns locally, in CI, or in-cluster on Kubernetes
- 07Regression detectionDiffs flagged before they reach production
See how the capture-replay engine works under the hood.
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Why teams switch from k6
Keploy eliminates manual test authoring by generating tests automatically from real traffic — no scripts, no stubs, no infrastructure setup.
You need functional API tests generated from real traffic automatically
Your primary concern is API correctness and regression detection
You want zero-code-change test generation with eBPF capture
The numbers behind the switch
Industry data on how much manual testing costs teams — and what Keploy delivers from the first recording session.
Writing tests, configuring mocks, debugging flakiness — not building features that ship.
A routine rename or interface change silently invalidates more than half your suite.
Keploy generates tests from every request your API actually handles — no guessing.
Traffic capture reaches edge cases, error paths, and concurrent requests no dev would write.
Pain stats sourced from developer productivity surveys. Coverage stats from Keploy production recording sessions across 50+ engineering teams.
Every number here comes from teams running Keploy in CI.
Zero code. Real tests. Automatically.
Keploy's eBPF agent intercepts every API call at the kernel level and turns live traffic into test cases with dependency mocks — no SDK, no sidecars, no annotations.
Incoming API Requests
Every API call your app makes gets captured, replayed as a test, and its dependencies auto-mocked — continuously, from real traffic.
How they compare, dimension by dimension
A logical breakdown across the dimensions that matter. Click any row for real-world KPI impact across industries.
Auto-generates from real API traffic via eBPF
Manual JavaScript test scripts for load scenarios
Zero code changes for test generation
Write JavaScript test scripts with k6 API
Auto-generates mocks for all dependencies
No mock generation — tests against live services
Native CLI and Docker support in CI
CLI-native with cloud and CI integrations
Go, Java, Node.js, Python and more
JavaScript/TypeScript test scripts for any API
Apache 2.0, fully open source, 20K+ stars
AGPL v3, open source, 26K+ stars
Click any dimension to see real-world KPI impact across industries.
Dive into how each capability actually works.
Your tests miss more than you think
Manual tests cover paths developers remember to write — usually just the happy path. Keploy captures every pattern production traffic actually generates.
Coverage grid shows 8 common endpoints × 10 production scenario types. Manual tests cover only what developers remember to write. Keploy captures every pattern your API actually serves in production.
Keploy is open source — read the code that captures this coverage.
The infrastructure you're maintaining
Traditional testing stacks require a shadow infrastructure to exist alongside your real app. Keploy eliminates all of it — tests and mocks come from actual traffic, not from services you run and maintain.
How they work differently
Architectural differences that affect workflow, cost, and velocity.
Keploy captures real API traffic and generates functional integration tests with auto-mocked dependencies. It focuses on verifying API correctness by replaying real traffic and detecting behavioral changes between versions.
k6 is a developer-centric load testing tool where you write performance test scripts in JavaScript. It simulates concurrent virtual users hitting your APIs to measure response times, throughput, and error rates under load. It integrates deeply with Grafana for observability.
When to use each tool
Specific scenarios where each tool delivers the most value.
Keploy is the better fit when…
- You need functional API tests generated from real traffic automatically
- Your primary concern is API correctness and regression detection
- You want zero-code-change test generation with eBPF capture
- You need auto-generated mocks for dependency isolation
- You want tests that verify API response correctness, not just performance
k6 is the better fit when…
- You need to measure API performance under concurrent load
- Your team wants to identify bottlenecks and performance regressions
- You need configurable load patterns with ramping virtual users
- You want deep Grafana and Prometheus integration for metrics
- You need to validate SLAs and performance budgets in CI
Compare the full workflow for your own stack.
The workflow you're escaping
Same starting point, same finish line. One path is short because Keploy does the tedious middle for you — the other is where teams lose days every sprint.
Without Keploy (k6 / manual)
Every dependency is your problem, and every code change ripples back through the test suite you hand-built.
With Keploy
Record once from real traffic, replay anywhere. Tests and mocks are generated and stay in sync automatically.
Cut the maintenance middle out of your test suite.
The test maintenance trap
With k6, every feature commit generates a hidden tax — a follow-up "fix tests" commit. The commit history tells the whole story.
Deterministic replays, no flaky tests — see how.
Switch from k6 in minutes
Choose the path that fits your workflow. Both are up and running the same day.
Install, record real API traffic, then replay it as regression tests — zero code changes, zero framework dependencies.
# 1. Installcurl --silent -O https://keploy.io/install.sh && source install.sh# 2. Record your traffickeploy record -c "your-start-command"# 3. Replay as testskeploy test -c "your-start-command" --delay 10Paste your cURLs, drop in an OpenAPI spec or Postman collection, and click Generate. Keploy builds your test suite in seconds.
Real-world scenarios
How Keploy handles the challenges your team actually faces.
API Regression Testing
Keploy replays recorded production traffic and compares API responses to detect functional regressions. Tests run fast with mocked dependencies and catch behavioral changes.
k6 can detect performance regressions by comparing response time thresholds across runs. However, it does not validate API response correctness or detect functional regressions in payloads.
Performance Benchmarking
Keploy focuses on functional correctness rather than performance. It validates that APIs return correct responses but does not measure throughput or latency under load.
k6 excels at performance benchmarking with configurable virtual users, ramping patterns, and detailed metrics. It measures response times, throughput, and error rates with Grafana dashboards.
Join the teams shipping with confidence on Keploy.
What you write vs what Keploy writes
The same test coverage — one approach takes hours of setup and ongoing maintenance, the other takes five minutes and zero boilerplate.
Every new endpoint needs a new file. Every refactor breaks tests. Every non-deterministic value (timestamps, IDs) needs custom handling.
Keploy captures the real request, response, and all dependency calls. Non-deterministic fields are auto-detected and excluded from assertions.
Frequently asked questions
Common questions about choosing between Keploy and k6.
Still have questions? The docs and community can help.
Looking for a k6 alternative?
Engineering teams evaluating k6 alternatives often compare it with Keploy for API testing and regression coverage. Keploy captures real production traffic via eBPF and auto-generates tests with dependency mocks — requiring zero code changes. The key differences come down to how tests are generated (traffic-based vs manual), how dependencies are mocked (automatic vs configured), and what infrastructure changes are needed (none vs SDK/sidecar/containers).
Ready to stop writing tests manually?
Keploy captures your real API traffic and turns it into a regression suite automatically. Zero code changes. Full coverage from day one.