Format
JSON Formatter & Validator
Pretty-print, minify and validate JSON in the browser.
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Basic
What it is & how to use it
JSON is structured text for data interchange. This tool pretty-prints, minifies and validates so invalid commas, quotes or brackets fail fast.
How to use the JSON Formatter & Validator
1) Paste JSON.
2) Format or minify.
3) Fix validation errors.
4) Copy the result into configs or APIs.
Intermediate
Formula & worked example
Objects use {}; arrays use []; keys are double-quoted strings; trailing commas are invalid in standard JSON.
Example error: single quotes or comments left in “JSON”.
Advanced
Interpretation, edge cases & next steps
Valid JSON can still be the wrong schema for your API.
Advanced: minify for transport; pretty-print for reviews; never paste secrets into shared demos.
Pairs with Base64/URL tools for encoding pipelines.
Frequently asked questions
Why did parse fail?
Usually trailing commas, single quotes or comments.
Does this call an API?
Formatting runs in your browser.
Huge payloads?
Very large files may stress the tab — split if needed.
Unicode?
Yes — modern JS JSON handles Unicode.
Related tools?
Base64 and URL encoder for adjacent jobs.
Deep guide
Read the full guide
Longer teaching, worked scenarios and mistakes — then jump back into this tool with example numbers.