JSON Tools Online
Free online JSON utilities for developers — format, validate, minify, visualize and compare JSON entirely in your browser. No signup required, no data sent to any server.
Paste minified JSON, API responses or config files and beautify them instantly with syntax highlighting, key sorting and indentation options.
Check and lint JSON syntax online — get exact error line and column positions. Works on minified JSON, API responses and config files.
Compress JSON by stripping whitespace and line breaks to reduce payload size before sending API responses or storing config data.
Visualize and explore JSON as an interactive collapsible tree. Search keys, expand nested objects and copy values from large API responses.
Compare two JSON files or objects and highlight every difference — added keys, removed values and changed properties with dot-notation paths.
About These JSON Tools
JSON (JavaScript Object Notation) is the standard data format used in APIs, configuration files, and databases. Whether you are debugging an API response, preparing data for production, or comparing two versions of a config — these tools cover the full JSON workflow.
Every tool runs entirely in your browser using JavaScript. No data is uploaded, stored or transmitted. This makes them safe to use with sensitive API keys, authentication tokens and production data.
All tools are free with no usage limits. No account, no signup, no tracking.
Frequently Asked Questions
Are these JSON tools free?
Yes, all JSON tools on DevToolHeaven are completely free with no signup, no account, and no usage limits.
Is my JSON data safe to paste here?
Your data never leaves your browser. All processing happens locally using JavaScript — nothing is sent to any server.
Which tool should I use to fix a JSON error?
Use the JSON Validator — it pinpoints the exact line and column of the error and explains what went wrong.
What is the difference between formatting and minifying JSON?
Formatting (beautifying) adds indentation and line breaks to make JSON human-readable. Minifying removes all whitespace to make it smaller for production use.
Can I compare two JSON API responses?
Yes — use the JSON Diff Checker to paste both responses and instantly see every key that was added, removed or changed.