JSON Studio

API Payload Size Analyzer

Find out exactly which keys in your massive API responses are causing network bloat. Visualize your JSON node sizes in an interactive dashboard.

JSON Payload
Paste your heavy API response JSON here to analyze which keys are bloating it...
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Size Breakdown

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Paste a massive payload to see exactly where the bytes are going.

Optimize Mobile & Web Network Performance

Large API payloads directly slow down mobile application render times and consume user bandwidth. While it's easy to see the aggregate size of a response via Chrome DevTools, it's incredibly difficult to figure out exactly what is taking up the most space.

How It Works

📊 Array Aggregation

If your root JSON is an array of records, the analyzer parses all records and aggregates the size of identical properties, showing cumulative cost of each column.

🔍 Object Analysis

If your root JSON is an object, it measures the exact byte size of every top-level key and builds an intuitive Pie Chart and Data Table.

🔒 Client-Side Processing

Measurements are done strictly on your device using native Blob byte-size extraction for high precision. Your data never leaves the browser.

Related JSON Tools

After identifying bloated keys, format the JSON to review the structure. Convert data to CSV for reporting. Fetch API responses with the JSON Fetcher and analyze their size.

Frequently Asked Questions

It calculates the byte size of your JSON payload (raw, minified, and gzipped), shows a treemap visualization of which keys and nested objects consume the most space, and provides optimization suggestions.
Large JSON payloads slow down API responses, increase bandwidth costs, and degrade user experience. Identifying the heaviest fields helps you optimize your API design.
Yes. The tool shows both raw byte size and estimated gzipped size, which is what actually travels over the network in most production configurations.
No. The byte-size calculations and treemap rendering are performed entirely on your machine. Your API responses and metadata never leave your browser sandbox.

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