Best Free Developer Tools Online: JSON, Base64, Hash Generator & More

Every developer needs quick access to encoding, formatting, and generation tools. This guide covers the best free online developer tools that work right in your browser—no installation, no registration required.

Why Browser-Based Developer Tools?

As a developer, you constantly need to format JSON, encode strings, generate hashes, or create UUIDs. While you could install CLI tools or IDE extensions, browser-based tools offer unique advantages:

Essential Developer Tools

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JSON Formatter & Validator

Format, beautify, and validate JSON data. Spot syntax errors instantly with clear error messages.

Try JSON Formatter →
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Base64 Encoder/Decoder

Encode text to Base64 or decode Base64 strings. Essential for working with APIs and data URIs.

Try Base64 Tool →
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Hash Generator

Generate MD5, SHA1, SHA256, and SHA512 hashes from any string. Verify data integrity instantly.

Try Hash Generator →
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URL Encoder/Decoder

Encode special characters for URLs or decode URL-encoded strings. Handle query parameters safely.

Try URL Encoder →
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UUID Generator

Generate random UUIDs (v4) in bulk. Perfect for database records, API testing, and mock data.

Try UUID Generator →
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HTML Entity Encoder

Convert special characters to HTML entities or decode them. Prevent XSS vulnerabilities.

Try HTML Encoder →

Data Formatting

JSON Formatter: Your Daily Companion

If there's one tool every developer uses daily, it's a JSON formatter. Arrow One's JSON Formatter does more than just beautify:

Text Comparison & Diff Checking

Need to compare two versions of a configuration file or API response? Our Diff Checker highlights additions, deletions, and changes line by line.

Security & Encoding Tools

Hash Generation

Hash functions are essential for password storage, data integrity, and checksums. The Hash Generator creates:

Base64 Encoding

Base64 encoding is everywhere in web development—embedding images in CSS, handling binary data in JSON, and basic authentication headers. Our encoder handles:

Text Utilities

Case Converter

Quickly transform text between different cases: UPPERCASE, lowercase, Title Case, camelCase, snake_case, and kebab-case. Perfect for normalizing variable names or formatting content.

Try Case Converter →

Word & Character Counter

Track your content length with real-time word, character, sentence, and paragraph counts. Useful for:

Try Word Counter →

🛠️ All Developer Tools, 100% Free

No registration. No API keys. Just powerful tools that work.

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Privacy & Security

A key advantage of Arrow One's developer tools: all processing happens locally in your browser. Your JSON, hashes, and encoded data never leave your device. This matters when working with:

Conclusion

Every developer deserves access to fast, reliable, and private development tools. Arrow One's complete suite of online utilities covers encoding, formatting, generation, and transformation—all free, all browser-based.

Bookmark the Tools Hub and make these your go-to developer utilities.