What kinds of failures can it create?
Missing fields, wrong types, and truncated or structurally broken payloads.
Data tool
API Response Corruptor
Generate bad API responses on purpose so you can test frontend error handling, schema validation, retry logic, importers, and edge cases.
Runs Locally
This tool runs in your browser. Files never leave your device.
Drop a JSON/TXT file here or paste a response body below.
Drag and drop a .json or .txt file anywhere inside this input card.
Size
680 B
Lines
37
Keys
27
Objects
6
Arrays
1
Corrupted response
490 B output · valid JSON
Validation status
Output can still be parsed as JSON, but its values/schema may be intentionally wrong.
API damage controls
Tune the exact failure modes you want your app to survive.
What this tool does
API Response Corruptor produces malformed versions of API responses, with missing fields, wrong types, truncated payloads, and broken structure, so you can see how your frontend and backend behave when an API misbehaves. It is the way to test the unhappy paths that are hard to trigger on purpose.
How it works
Paste a sample response, choose how to break it, and the tool generates corrupted versions in your browser. Copy them into your tests or mocks. Nothing is uploaded.
When to use API Response Corruptor
Testing how a frontend handles a broken response
Hardening error handling on the backend
Building mocks for failure scenarios
Checking retries and fallbacks against bad payloads
FAQ
Does it change my sample?
It corrupts copies; your original stays intact.
Are my files uploaded anywhere?
No. Everything runs in your browser and the data never leaves your device.