
What Checkly Can’t Test, Keploy Cancatch what breaks
Auto-Generated Tests from Traffic vs Monitoring-as-Code Synthetic Checks
Keploy captures real production traffic with eBPF and auto-generates API tests plus mocks pre-release, requiring zero code changes. Checkly is code-first synthetic and API monitoring: developers define API and Playwright browser checks as TypeScript via the Checkly CLI, then run them continuously from global locations to detect production issues. Keploy suits teams wanting pre-merge regression coverage; Checkly suits teams wanting always-on production monitoring and alerting.
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 Checkly
Keploy eliminates manual test authoring by generating tests automatically from real traffic — no scripts, no stubs, no infrastructure setup.
Want to catch regressions before code ships, not after it reaches production
Need auto-generated tests from real traffic without writing check scripts
Need automatic mock generation for downstream dependencies in CI
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.
Pre-release regression testing from real traffic
Continuous production synthetic and API monitoring
Auto-generates from captured production traffic via eBPF
Developers author API and Playwright checks as TypeScript code
Zero code changes needed to instrument or capture
No app changes, but checks are written and maintained as code
Auto-generates mocks for all downstream dependencies
Not a focus — checks hit live endpoints and real UIs
Locally, in CI, or on Kubernetes
Scheduled from 20+ global locations, plus private locations
Built-in time-freezing and field normalization
Handled per-check via custom assertions in TypeScript
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 uses eBPF to record real API calls and responses from your running application, then replays them as regression tests before code ships. It auto-generates mocks for downstream dependencies and handles non-deterministic fields like timestamps through time-freezing. It focuses on catching regressions in CI or locally, so bugs are caught before release rather than observed in production.
Checkly is a monitoring-as-code platform where developers define checks — API checks and Playwright-based browser checks — as TypeScript, version them in their repo, and deploy them via the Checkly CLI. Checks run continuously on a schedule from 20+ global locations, with uptime and heartbeat monitoring, OpenTelemetry tracing, and alerting. It observes live production behavior and pages you when something breaks.
When to use each tool
Specific scenarios where each tool delivers the most value.
Keploy is the better fit when…
- Want to catch regressions before code ships, not after it reaches production
- Need auto-generated tests from real traffic without writing check scripts
- Need automatic mock generation for downstream dependencies in CI
- Prefer an open-source, self-hosted tool with an Apache 2.0 license
- Want language-agnostic capture at the network level, not code-first scripting
Checkly is the better fit when…
- Need always-on production monitoring and alerting, not just pre-release tests
- Want to run synthetic checks from many global locations continuously
- Prefer defining monitors as versioned TypeScript with a CLI (monitoring as code)
- Need Playwright browser checks and uptime/heartbeat monitoring in one platform
- Want OpenTelemetry tracing tied to synthetic check failures
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 (Checkly / 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 Checkly, 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 Checkly 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.
You want to catch a breaking API change before it ships
Keploy replays captured production traffic against the new build in CI, so a changed response or broken dependency fails the pipeline before the change reaches production, with mocks making the run deterministic.
Checkly catches the issue after deployment: its scheduled checks hit the live endpoint and alert you once the regression is already in production, which is detection rather than prevention.
You need to know your production API is up and correct 24/7
Keploy is not a production monitor; it generates and replays regression tests pre-release rather than continuously probing live endpoints from around the world.
Checkly is purpose-built for this — API and browser checks run on a schedule from 20+ global locations with uptime and heartbeat monitoring and alerting, so you learn immediately if production breaks or degrades.
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 Checkly.
Still have questions? The docs and community can help.
Looking for a Checkly alternative?
Engineering teams evaluating Checkly 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.