JSON Size Analyzer
Free JSON size analyzer. See size per property in bytes, KB, MB. Paste or upload JSON; sort by size, original or alphabetical order. No server upload—100% in your browser.
What is the JSON Size Analyzer?
The JSON Size Analyzer is a free online tool that shows the size of your JSON in bytes, KB, or MB, and breaks down how much each property contributes. Paste JSON or upload a .json file, then click Analyze JSON to see an expandable tree with percentage bars. All processing runs in your browser; nothing is sent to the server.
Why check JSON size?
Knowing which keys or arrays use the most space helps you reduce API payload size, debug large responses, and keep config files lean. Sort results by size (largest first), original order, or alphabetically.
FAQ
What is a JSON size analyzer?
A JSON size analyzer shows how much space each property in your JSON uses (bytes, KB, MB). It helps you find what makes your payload large so you can optimize.
How do I check JSON file size?
Paste your JSON or upload a .json file, then click Analyze JSON. You get the total size and a per-property breakdown with bars. Sort by size, original order, or A–Z.
Is the JSON size analyzer free and private?
Yes. The tool is free and runs entirely in your browser. Your JSON is never sent to any server.