Format JSON
Indent valid JSON so nested objects, arrays, and values are easier to read.
Open formatter
JSON developer tools
JSON formatter and validator
Paste JSON to format it, confirm that it parses, reduce its size, compare two versions, or inspect its structure. The work stays in this browser.
- Input
- JSON text that you provide.
- Processing
- Runs in this browser; input is not uploaded.
- Output
- Copy or download the generated result.
The example contains three previously published CISA Known Exploited Vulnerabilities records from 2021-2024. It is a historical format example.
Related checks
Compare versions or prepare an import.
Use these checks when formatting alone does not answer the question.
Validate JSON
Confirm that the input parses and review its root type and top-level keys.
Open validatorMinify JSON
Remove formatting whitespace while preserving the parsed values and structure.
Open minifierCompare two objects
List changed top-level fields and inspect the earlier and later values.
Compare JSONFlatten nested data
Turn nested object paths into a flat key-value structure for review or tabular work.
Flatten JSONValidate JSON Lines
Check newline-delimited records and identify malformed lines without discarding them.
Validate JSONLCommon uses
Inspect the payload before it enters a system.
Formatting makes data readable. Validation confirms syntax. Neither one proves that a payload matches a business contract, authorization rule, or API schema.
API payload review
Format and validate a response before comparing its fields with the documented API contract.
Configuration checks
Make nested configuration readable and compare a proposed revision with the current version.
JSONL data preparation
Find malformed records before a newline-delimited file enters an import, training, or processing job.
Checking the same payload every day?
Commission a validation workflow with your schema, exception report, and delivery rules. The free formatter remains available for individual checks.