API Traffic Replay Testing: The Definitive Guide (2026)
API traffic replay testing guide with verified examples. Compare GoReplay, WireMock, Speedscale and proxymock, and see what a CI replay gate proves.
Read the guideTraffic replay guides
Traffic replay: test changes against real API behavior
Capture production interactions, remove sensitive data, and replay the same behavior in development, staging, or CI. These guides cover the workflow from first recording to release gate.
Start here
Start with the complete traffic replay guide
Choose what you need to do
Learn how replay works
Understand capture, isolation, replay, and the tradeoffs behind a production-grade system.
Apply it to delivery
Use recorded traffic for debugging, migrations, refactoring, and CI regression tests.
Handle real-world data
Protect sensitive payloads and solve the authentication problems that appear during replay.
All traffic replay articles
How to Use Automatic Release Readiness Scorecards
Use Speedscale's readiness scorecard to compare three API gateway builds on Kubernetes. Catch a broken endpoint, test a retry and gate CI on the verdict.
Automatic Release Readiness Scorecards
Speedscale's release readiness scorecards grade replay results, explain release blockers, and track accepted findings against your team's configured rules.
Load Test PostgreSQL Instantly using Production Recordings
Record the queries your app sends to PostgreSQL in Kubernetes, then replay them against a QA database as a load and regression test. No scripts to write.
Playwright End-to-End Testing with Recorded API Mocks
Run Playwright tests with recorded API mocks, diagnose UI and API failures, then run the same specs in Kubernetes. Use the lab's commands and screenshots.
Oracle JDK to OpenJDK: A Guide to Reliable Migration Testing
Validate Oracle JDK to OpenJDK migrations with traffic replay. Compare API behavior, check TLS connections, and measure repeatable performance results.
mitmproxy vs. proxymock for API Traffic Replay
A pragmatic comparison of mitmproxy and proxymock for traffic replay. Learn which tool to use for investigative debugging vs developer productivity, how.
Test Your MySQL 8.4 Upgrade With Real App Queries
Replay your app's recorded MySQL statements against 8.4 to catch upgrade regressions, then load test the database with the same workload using proxymock.
Test PostgreSQL With the Queries Your App Actually Runs
Replay recorded PostgreSQL queries to catch schema regressions and run realistic database load tests with proxymock, using the CLI or an AI assistant.
Use AI and traffic replay to test AI-generated code
Have your coding agent test AI-generated code with proxymock: capture working API traffic, replay it against changes, and inspect the results.
Replay real traffic before release
Turn production API behavior into repeatable tests without writing every scenario by hand.