Can I control the damage?
Yes. Choose the type and severity of the corruption.
Data tool
JSON Corruptor
Break JSON on purpose to test validators, API clients, importers, error handling, and messy-data cleanup flows.
Runs Locally
This tool runs in your browser. Files never leave your device.
Drop a JSON/TXT file here or paste JSON below.
Drag and drop a .json or .txt file anywhere inside this input card.
Lines
29
Objects
4
Arrays
3
Keys
21
Corrupted output
468 B output · invalid JSON
Output validation
Expected property name or '}' in JSON at position 31 (line 5 column 1)
Damage controls
Use custom sliders when you need a specific kind of broken JSON.
What this tool does
JSON Corruptor takes valid JSON and breaks it in controlled ways, dropping brackets, mangling quotes, and injecting noise, so you can test how your code handles bad input. It is built for hardening parsers and error handling against the malformed JSON that shows up in the real world.
How it works
Paste valid JSON, choose how to corrupt it, and the tool generates broken versions in your browser. Copy the output to feed into your tests. Nothing is uploaded.
When to use JSON Corruptor
Testing a parser's error handling
Hardening an API against malformed payloads
Building negative test cases for JSON input
Checking how a UI handles a bad response
FAQ
Does it keep a clean copy?
It corrupts a copy; your original JSON stays intact.
Are my files uploaded anywhere?
No. Everything runs in your browser and the data never leaves your device.