Free Online Developer Utilities

47 developer tools — JSON, encoding, hashing, regex, diff, cron, CSS generators, SQL helpers, code generators, markdown tools, API utilities, and fake data generation. All in your browser.

Tools

JSON Formatter

Format, minify, and validate JSON with syntax highlighting.

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Base64 Encoder/Decoder

Encode text to Base64 or decode Base64 back to text with Unicode support.

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URL Encoder/Decoder

Encode special characters for URLs or decode percent-encoded strings.

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JWT Decoder

Decode JSON Web Tokens to inspect header, payload, and signature.

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Hash Generator

Generate MD5, SHA-1, SHA-256, SHA-512 hashes. Compare hashes for integrity.

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Regex Tester

Test regex patterns with real-time match highlighting and common patterns library.

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Diff Checker

Compare two texts side by side with color-coded line-by-line differences.

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Cron Generator

Build cron expressions visually with explanations and next run times.

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CSS Gradient

Build linear, radial, and conic gradients with color stops and live preview.

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Box Shadow

Design box shadows visually with offset, blur, spread, and color controls.

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Border Radius

Control individual corner radii with live preview and CSS output.

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Flexbox Builder

Build flexbox layouts interactively with container and item controls.

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Grid Builder

Create CSS Grid layouts with visual preview and generated code.

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Animation Builder

Design CSS keyframe animations with visual timeline and live preview.

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Test Generator

Generate unit test cases for JavaScript, Python, and Java functions.

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Notepad

Distraction-free text editor with auto-save, multiple notes, and export.

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Markdown Editor

Write markdown with live split preview, toolbar, and HTML export.

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Table Generator

Build tables visually and export as HTML, Markdown, CSV, JSON, or LaTeX.

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API Tester

Test REST APIs with headers, auth, body editor, history, and code snippets.

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Fake Data Generator

Generate realistic fake data as JSON, CSV, or SQL INSERT statements.

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How It Works

Step 1

Choose Tool

Pick from 47 tools — JSON, encoding, CSS, SQL, code, markdown, API, and more.

Step 2

Paste Input

Type or paste your text, JSON, URL, or token into the input area.

Step 3

Get Results

See instant results. Copy output with one click. Nothing sent to servers.

Frequently Asked Questions

Is FreeDevKit really free?▼

Yes, 100% free. No sign-up, no usage limits, no ads blocking the tools. Use all developer utilities without restriction.

Is my data safe?▼

Absolutely. All processing happens entirely in your browser. Your data is never uploaded to any server. We cannot see, access, or store your input.

What developer tools are available?▼

FreeDevKit includes JSON Formatter, Base64, URL Encode, JWT Decoder, hash tools, Regex Tester, Diff Checker, Cron Generator, CSS generators, SQL helpers, code generators, Markdown tools, API utilities, and data generators. All free with no sign-up.

Do I need to create an account?▼

No. FreeDevKit works instantly with zero sign-up. Just open the tool, paste your input, and get results.

Does FreeDevKit work offline?▼

Once the page is loaded, all tools work without an internet connection since everything runs in your browser using JavaScript.