jsonpost
Generators & Utilities

JSON Size Analyzer

Analyze JSON byte size, key count, nesting depth, and estimated gzipped size over the wire.

Runs entirely in your browser — your data never leaves your device.

Loading tool…

How to use this tool

  1. 1Paste your JSON into the editor.
  2. 2View total size, minified size, and estimated gzipped size.
  3. 3Identify the heaviest keys and arrays.

Frequently asked questions

Does it estimate gzipped size?
Yes. It estimates the compressed size your JSON would have over the wire, which is what most APIs actually transfer.
Can it find the heaviest fields?
Yes. It breaks down which keys and arrays contribute most to the total size.
Is my data uploaded to a server?
No. Every tool on JSONPost runs entirely in your browser using JavaScript. Your JSON never leaves your device, so it is safe to use with private or sensitive data.

Related tools

JSON Stats & Tree Statistics

Get instant statistics on any JSON: total keys, value-type breakdown, array lengths, and max depth.

JSON Minifier & Compressor

Compress JSON by removing all whitespace and line breaks to shrink API payloads and save bandwidth.

JSON Formatter & Beautifier

Format and beautify your JSON instantly with customizable indentation and a collapsible tree view.