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Free Online Developer Tools

Format JSON, generate UUIDs, encode Base64, minify CSS, and check password strength — all free, fast, and browser-based developer utilities.

5 free tools available

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JSON Formatter & Validator

Format messy JSON and validate syntax with readable error guidance.

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Password Strength Checker

Check password strength and get actionable improvement suggestions.

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UUID Generator

Generate bulk UUIDs and understand common UUID versions quickly.

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Base64 Encoder / Decoder

Encode or decode text and files in Base64 format instantly.

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CSS Minifier & Beautifier

Minify CSS for production or beautify compressed styles for editing.

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About our developer tools

Streamline your development workflow with free browser-based utilities. Format and validate JSON payloads, generate unique identifiers, encode and decode Base64, minify or beautify CSS, and check password entropy — all without leaving your browser or sending data to a server. Built for front-end and back-end developers who value speed and privacy.

Every tool in this category runs entirely in your browser — your data never leaves your device. There is no account to create, no download to install, and no usage limit. Just open the tool, enter your data, and get instant results. This privacy-first approach makes ToolNest trusted by thousands of professionals, students, and hobbyists worldwide.

Each tool includes detailed instructions, real-world examples, frequently asked questions, and links to related utilities. Whether you are a beginner or an experienced professional, you will find the guidance you need to use each tool effectively. Bookmark this page to return quickly whenever you need a developer tool.