ToolMaster

Free Developer Tools Online

Essential developer utilities that run instantly in your browser. Format and validate JSON, encode/decode Base64, generate UUIDs, test regex patterns, decode JWT tokens, and test APIs — no account required, all private.

All 8 tools

JSON Formatter & Validator

Format, validate, and beautify JSON with syntax highlighting and error detection.

Base64 Encode / Decode

Encode and decode Base64 strings instantly with copy-to-clipboard support.

UUID Generator

Generate unique identifiers (UUID v4) for your applications and databases.

QR Code Generator

Generate customizable QR codes for URLs, text, and more. Download as high-quality PNG.

Hash Generator

Generate SHA256, MD5, SHA1, and other hash values from text input.

Regex Tester

Test and debug regular expressions with real-time matching and highlighting.

JWT Decoder

Decode and inspect JWT tokens client-side. No data sent to servers.

API Tester

Test REST APIs with a professional interface. Supports headers and raw JSON body.

Frequently Asked Questions

Are ToolMaster Free Developer Tools Online really free?

Yes. Every tool is 100% free with no usage limits, no watermarks, and no account required.

Do my files get uploaded to your servers?

No. ToolMaster processes files locally in your browser. Your data never leaves your device — unlike most competitors.

How is ToolMaster different from cloud-based tool sites?

ToolMaster runs entirely in your browser for maximum privacy and speed. No cloud upload means your confidential documents stay on your device.

Can I use these tools on mobile?

Yes. All tools work on Android and iPhone browsers — Chrome, Safari, and Firefox.

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