Damage JSON

How to use Damage JSON

1. 1. Paste valid JSON. Put a well-formed JSON document into the input pane. This is the starting point that gets deliberately broken according to how many errors you request.
2. 2. Set the number of Errors. Enter how many random syntax mistakes to introduce, such as a missing quote, a dropped comma, or a stray colon. More errors produce a more thoroughly broken document.
3. 3. Copy the damaged result. Copy the resulting broken JSON and feed it into whatever you're testing, whether that's a parser's error handling, a form validator, or a repair tool.

When to use Damage JSON

Damage JSON deliberately introduces random syntax errors into an otherwise valid document. Use Damage JSON whenever you need broken JSON on purpose, most often to test how something else responds when the input isn't well-formed.

• Testing a parser's error messages. You want to verify a custom JSON parser produces clear, useful error messages rather than a generic failure when it encounters common mistakes like a missing comma.
• Verifying a form validator catches bad input. A form accepts a JSON blob as input, and you want to confirm the validation logic properly rejects malformed JSON instead of silently accepting it or crashing.
• Creating fixtures for a JSON repair tool. You are building or testing a tool that fixes broken JSON, and you need a reliable way to generate damaged input with a known number of errors to check against.
• Teaching common JSON syntax mistakes. A workshop on JSON wants to show students what typical mistakes look like, like a missing quote or an extra comma, using a document that started out perfectly valid.

Examples

{"name": "Ada", "age": 36}

{"name: "Ada" "age":36

About the Damage JSON tool

Frequently asked questions