JSON unique field check

Client

Validate primary-key columns in mock datasets before import.

Learn more: uniqueness

Returns `{ unique, duplicateValues }`.

Local processing

Parsing and output formatting run entirely in your browser—nothing is uploaded for this transform.

Input

?
Paste JSON, then read transformed output below.

Nearby workflows on Toolcore

  • JSON distinct rows by field — Deduplicate object rows by one field value—first row wins, local only. once JSON text parses on this page.
  • JSON unique by field — Deduplicate JSON array rows by one field—keep first or last; local only. once JSON text parses on this page.
  • JSON validate required fields — Check that every object row includes listed fields—comma-separated names. once JSON text parses on this page.
  • JSON formatter — JSON format online: pretty-print, minify, validate, escape, download . once JSON text parses on this page.

Common use cases

  • Validate primary-key columns in mock datasets before import.

Common mistakes to avoid

  • Invalid JSON

    Fix parse errors before expecting output.

FAQ

Is data uploaded?

No—all parsing and transforms run locally.

How is this different from jq?

This page focuses on one deterministic task without a filter language.

More tools

Related utilities you can open in another tab—mostly client-side.