JSON Size Analyzer
See the size, key count and gzip estimate of a JSON payload. Runs in your browser.
Runs in your browser — your file never leaves your deviceFrequently asked questions
Is JSON Size Analyzer free to use?
Yes — JSON Size Analyzer is completely free with no limits, no watermarks and no sign-up. It runs in your browser, so there is nothing to pay for.
Are my files uploaded or stored anywhere?
No. This tool does all its work locally in your browser using your own device's power. Your files never leave your device and we never see them.
Do I need to install anything or create an account?
No installation and no account needed. JSON Size Analyzer works on any modern browser — Windows, Mac, Linux, Android and iPhone.
How do I use JSON Size Analyzer?
Open the tool, add your file (or paste your content), adjust any options, then press “Analyze”. Your result is ready to download in seconds.