No, all processing happens locally in your browser. No data is ever sent to any server.

Does it work offline?

Yes, after initial load, JSON Toolbox works completely offline.

What formats are supported?

JSON, CSV, XML, YAML, CSS. Bidirectional conversion for most formats.

How do I validate JSON against a schema?

Use the Schema tab. Paste your JSON document and your JSON Schema, then click Validate. All violations are listed with their path and error message.

Are there keyboard shortcuts?

Yes, press ? to view all keyboard shortcuts. Ctrl+Enter runs the conversion in the active tab.

JSON Toolbox — Format, validate and convert JSON online

CSV to JSON

Coming soon

This feature is under development.

CSV

Ready

JSON Toolbox — frequently asked questions

How do I format JSON with proper indentation?

Open the Format tab, paste your JSON and choose the indent size (2 or 4 spaces). Click Format — the tool adds line breaks and indentation to make the structure readable. You can also minify JSON to strip all whitespace.

Supports 2- and 4-space indentation
Minify removes all line breaks and spaces
Formatted JSON can be sent directly to Validate or Diff
Shortcut: Ctrl+Enter runs the operation in the active tab

How do I convert CSV to JSON?

Paste your CSV data into the CSV tab. The tool auto-detects delimiters (comma, semicolon, tab). The result is a JSON array where each row becomes an object with column names as keys.

Auto-detection of comma, semicolon and tab delimiters
First row is treated as column headers
Bidirectional: CSV to JSON and JSON to CSV
Also supports XML, YAML and CSS to JSON

How do I repair broken JSON?

Paste your malformed JSON into the Fix tab. The tool finds and corrects the most common errors automatically — no manual debugging needed.

Missing quotes around keys
Trailing commas after the last element
Missing or extra brackets and braces
Single quotes instead of double quotes

What is the difference between JSON validation and schema validation?

Syntax validation checks that the document is valid JSON. Schema validation additionally checks that values conform to a specific JSON Schema — correct types, required fields and allowed values.

Validate tab: checks JSON syntax and reports line numbers for errors
Schema tab: validates against your own JSON Schema 4/6/7 document
All schema violations are listed with path and error message

Is it safe to paste sensitive data?

Yes. All processing runs in your browser — no network requests are made with your data. JSON Toolbox also works fully offline after the page has loaded.

No data is sent to any server
Works without internet after initial load
Available as a zero-telemetry build for air-gapped environments

Format conversion overview

Format	To JSON	From JSON	Tab
CSV	Yes	Yes	CSV
XML	Yes	Yes	XML
YAML	Yes	Yes	YAML
CSS	Yes	No	CSS
TypeScript interface	No	Yes	Transform
Go struct	No	Yes	Transform

JSON Toolbox

CSV to JSON

CSS to JSON

XML to JSON

YAML to JSON

JSON Formatting

JSON Validation

JSON Repair

JSON Diff

JSONPath Query

JSON Schema

Transform & Export

Utilities

Tree View

Pipeline Builder