About JSON Indent

What is JSON Indent?

JSON Indent is a free, browser-based collection of JSON utilities for developers. The suite currently includes a JSON Formatter, a JSON Validator, a JSON Minifier, a JSON Diff tool, and a JSON Converter. Every tool runs entirely in your browser — no account required, no data uploaded, no size limits.

The formatter beautifies compact JSON into readable, indented output. The validator checks syntax against RFC 8259 and reports the exact line and column of any error. The minifier strips all whitespace to produce the smallest valid JSON string. The diff tool compares two JSON objects and highlights every key that was added, removed, or changed. Together, they cover the most common JSON tasks a developer encounters in a typical workday.

How it started

JSON Indent started in 2018 as a personal weekend project. I was working on API integrations and spending too much time debugging raw JSON responses — pasting them into slow, ad-heavy tools that required accounts or uploaded data to a server. I wanted something fast, clean, and private. So I built a formatter that worked entirely in the browser.

The tool gained a small following. Over the years I added the validator (after getting tired of hunting through minified JSON for missing quotes), the minifier (for trimming API payloads before shipping), and the diff tool (for comparing config file revisions without false positives from key reordering). Each feature was added because I personally needed it, which is probably why developers tend to find it useful — it solves real problems rather than imaginary ones.

Today the site serves developers across more than 50 countries. Brazil, France, the United States, Italy, and India are the largest audiences. I've kept the interface in English with full-featured localized versions in Brazilian Portuguese and French.

Design principles

Client-side only. This is the most important constraint. Every JSON operation — formatting, validating, minifying, diffing — happens in your browser using JavaScript. Your data never touches a server. This matters when you're working with internal API responses, database exports, configuration files with credentials, or any other sensitive payload. There is nothing to log, because there is no server receiving your input.

No friction. There is no account, no subscription, no email required, no CAPTCHA, and no usage limit. Open the page, paste your JSON, and you're done. The tool loads in under a second on most connections and continues to work if your connection drops.

Plain technology. The site is built with plain HTML, CSS, and JavaScript. No framework, no build step, no dependency on external CDNs beyond Google Analytics. This keeps it fast, auditable, and easy to maintain. The source is available on GitHub.

Free, indefinitely. All tools are free to use. The site is supported by display advertising (not yet active) and by optional user support.

About the developer

My name is Vaibhav Kamble. I'm a software engineer based in the United States. JSON Indent is one of several free developer tools I maintain alongside my day job. You can read more about my work at vaibhavkamble.dev.

JSON Indent is part of a small family of similar tools: XML Indent covers XML formatting and validation, and YAML Indent covers YAML. All three share the same client-side philosophy and design system.

Get in touch

Found a bug? Have a feature request? Noticed something that could be better? I read every message. Use the contact form to reach me. Response times vary but I try to get back within a few days.