Developer Test Data Tools — UUID, JSON & SQL

Developer generators: UUID bulk, dummy JSON, SQL INSERT seeds, custom schema mock CSV/JSON/XML export free.

UUID, JSON, CSV, XML, SQL, JWT, formatters, converters, encoders, and Base64 utilities for development workflows. This category includes 20 free online tools on Random Data Hub, including UUID / ID Generator, Mock Data Generator, JSON Generator, SQL Dummy Data Generator, JWT Generator, Base64 Encode / Decode, and more. Each generator produces fictional data for QA, staging environments, and UI prototypes—never for fraud, spam, or impersonation. Select a tool below to generate sample output, read step-by-step instructions, and review frequently asked questions about safe test-data practices.

Generate UUID v4, NanoID, or ULID identifiers in bulk.

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Mock & random data generator—SQL, sample rows, 1,000 export.

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JSON random data—create dummy JSON user arrays for APIs.

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Dummy MySQL/Postgres data—INSERT scripts & database test seeds.

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Sample JWT-shaped tokens for auth UI demos only.

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Encode or decode text in the browser—no upload.

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Free online fake mac address generator for test data.

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IPv4 and IPv6 test addresses.

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Format SQL queries with clearer keywords and indentation.

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Build cURL commands from method, URL, headers, and body.

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Percent-encode text for safe use in URLs and query strings.

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Escape HTML entities for safe display in pages.

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Decode JWT header and payload without verifying signatures.

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Pretty-print HTML markup with clearer nesting.

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Format CSS rules with consistent braces and spacing.

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Format JavaScript for readability in reviews and docs.

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Test regular expressions against sample text in-browser.

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Generate an XML sitemap snippet from a list of URLs.

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Generate title, description, and robots meta tags for SEO.

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Generate basic JSON-LD schema markup for web pages.

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