Free Online Developer Tools

Codetools Guru is a collection of fast, free online developer tools: Base64 encoder, JSON formatter, JWT debugger, regex tester, password, UUID and timestamp generators. No signup, no ads, and everything runs in your browser.

Base64 Converter

Encode and decode text into Base64 format in real-time.

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JSON Formatter & Validator

Format, validate, and make your JSON code readable instantly.

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JWT Debugger

Decode and analyze your JSON Web Tokens securely in the browser.

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RegEx Tester

Test and debug regular expressions with live match highlighting.

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Password Generator

Create strong, random, and secure passwords instantly.

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URL Encoder & Decoder

Percent-encode and decode URLs and query string parameters.

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UUID Generator

Generate random UUID v4 identifiers in bulk, instantly.

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Unix Timestamp Converter

Convert Unix epoch timestamps to human-readable dates and back.

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Why use Codetools Guru?

Every tool runs 100% client-side: your tokens, JSON payloads and passwords are never uploaded to a server. Pages load instantly, work on desktop and mobile, and need no account.

Whether you need to decode a JWT, validate and beautify JSON, convert Base64, percent-encode a URL, test a regular expression or generate a UUID, you will find a focused tool for it here.

More developer tools coming soon.

Built for developers, by developers.