Free browser-based data tool

JSON Null & Missing Value Inspector

Find nulls, missing properties, and incomplete records instantly. Everything stays in your browser.

Your files never leave your computer.All processing happens locally inside your browser.

  • Discover root and nested arrays of objects
  • Separate missing, null, and empty-string values
  • Copy or download a deterministic completeness report
1

Upload JSON

Choose a JSON file. It is read only by this browser tab.

Drop a JSON file here

or use the file browser

2

Paste and validate JSON

UtilityDock discovers object arrays at the root and within nested paths.

Paste JSON or upload a file to begin.

What null and missing-value inspection is

A record-by-record measure of field completeness

Completeness inspection compares the fields discovered across every object in an array. It separates properties that are absent, explicitly null, or present as empty strings, then calculates the share of usable values for each field.

Data quality workflows

Find incomplete records before they enter another system

Review customer exports, event logs, configuration lists, or migrated records before importing them. Normalized paths aggregate repeated nested arrays so completeness remains comparable across the document.

API validation

Compare actual response coverage without generating a schema

Inspect saved API responses to see whether expected fields are populated across all resources. Null and missing values remain separate because they often represent different API behavior.

Analytics preparation

Measure dimension and metric coverage before analysis

Check identifiers, labels, categories, timestamps, and measures before loading a dataset into a spreadsheet or analytics pipeline. The report makes weak fields visible without changing the source.

Examples

Interpret each completeness signal precisely

Record valueReported as
"email": nullPresent and null
No email propertyMissing
"email": ""Present and empty string
"active": falseComplete

Inspection utilities

Continue with related UtilityDock inspection workflows

FAQ

Questions about JSON completeness

Does UtilityDock upload or store my JSON?

No. Your files never leave your computer. Validation, array discovery, completeness analysis, preview, copying, and report creation all happen locally inside your browser.

What counts as a complete value?

A value is complete when its property exists and the value is neither null nor an empty string. Zero, false, objects, and arrays count as complete values.

What is the difference between null and missing?

Null means the property exists with the JSON value null. Missing means the property does not exist in that record.

Are whitespace-only strings considered empty?

No. Version 1 counts only the exact empty string as empty. A string containing spaces remains present and complete.

Can the tool fix incomplete records?

No. Version 1 is read-only. It does not correct data, generate schemas, modify documents, or call APIs.