Free Developer Tools Online

Developer tools help you format, validate, test, and inspect code and API workflows without installing another application. The category is designed for product engineers, QA teams, and anyone who wants faster debugging in a browser tab.

From REST API inspection to JSON schema validation, these tools reduce the time between a problem and a testable fix. Use them to inspect payloads, clean up code, and generate safe outputs for staging, deployment, or documentation.

JSON Formatter & Validator

Beautify, minify, sort and validate JSON with query and tree helpers.

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API Tester

Test REST APIs directly in your browser. Set headers, auth, body and inspect responses without installing another client.

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HTML Entity Encoder/Decoder

Convert characters to HTML entities and decode entities back to text.

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Regex Tester

Find words of four or more word characters with a fixed JavaScript regex. Shows matches and their positions; custom patterns and flags are not supported.

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Meta Tag Generator

Generate SEO, Open Graph and Twitter meta tags with previews.

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SQL Formatter

Beautify or minify SQL queries with syntax highlighting and formatting options.

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cURL to Code

Convert cURL commands to JavaScript fetch, axios, or Python requests code.

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JSON Schema Validator

Validate JSON against draft-07 JSON Schema with Ajv format checks and error paths. Drafts 4, 6 and 2020-12 are not configured in this version.

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FAQ

What developer tools are included?

The developer category includes API Tester, JSON Formatter, JSON Schema Validator, Regex Tester, SQL Formatter, cURL to Code, HTML Entity tools, and metadata helpers.

Do these tools keep data private?

Yes. Most developer tools process input locally in the browser, and the API Tester routes requests through a server-side proxy. Headers and bodies are sent to that proxy and the target API.

Can I use these tools for debugging and QA?

Absolutely. They are useful for testing endpoints, validating payloads, comparing strings, and preparing output for documentation or release notes.