JSON Size Calculator – Check JSON File Size
Calculate the exact size of your JSON in bytes, KB, and MB. Compare minified vs formatted size instantly with our free JSON Size Calculator to optimize data transfer.
About JSON Size Calculator
JSON file size affects API response times and bandwidth usage. Knowing the exact byte count helps optimize data transfer and estimate storage requirements. This JSON Size Calculator shows current size, minified size, and potential savings from removing whitespace.
How it works
Paste your JSON into the input area. The tool instantly displays the current size in bytes, KB, or MB. Cards show minified size and formatted size side by side so you can compare the impact of whitespace.
Use the Format Indent dropdown to see how different indentation levels affect file size. Click Minify to remove all whitespace, or Beautify to format with your chosen indent. The Copy Size Report button generates a summary you can share.
When you'd use this
API developers optimizing response payloads need to know how much size reduction minification provides. Mobile developers working with limited bandwidth benefit from understanding the trade-off between readable and compact JSON.
This tool measures raw byte size, not compressed size. In production, gzip or brotli compression reduces JSON significantly regardless of formatting. Use this calculator for uncompressed scenarios like localStorage or database storage.
Questions
How is size calculated?
Size is measured in bytes using UTF-8 encoding, which accurately reflects storage and transfer requirements.
What is the potential savings?
Savings shows the byte difference between formatted and minified JSON, plus the percentage reduction.
Does it count characters or bytes?
Bytes. Multi-byte Unicode characters are counted correctly, unlike simple character counts.
Can I see line and character counts?
Yes. Below the input area, character count and line count are displayed for additional context.
Is there a file size limit?
The tool runs in your browser, so very large files may cause slowdowns. Files under 10MB work smoothly.