Fast, secure, and runs in your browser
Free Developer Tools for Debugging, Formatting, and Encoding
DevToolz is a curated collection of free, open-source developer utilities designed to handle your most common daily tasks without tracking or storing your data.
Secure & Private
Everything runs locally in your browser. We never send your sensitive tokens or data to our servers.
Real-time Validation
Built with modern web technologies to ensure instant feedback and zero loading states.
Developer Friendly
Clean interfaces, keyboard shortcuts, and formatted outputs designed specifically for engineers.
Available Tools
Select a tool below to get started. We're constantly adding new utilities to help streamline your development workflow.
JWT Decoder
Decode JSON Web Tokens instantly in a clean, readable format. Inspect headers, payloads, and verify expiration timestamps.
- Real-time base64 decoding
- Human-readable timestamps
- Formatted JSON output
Base64 Encoder
Encode and decode text to and from Base64 format with real-time two-way conversion and UTF-8 support.
- Two-way real-time conversion
- Full UTF-8 character support
- Copy and clear utilities
JSON Formatter
Format, validate, and minify JSON data instantly. Catch syntax errors with real-time validation.
- Real-time formatting & minifying
- Instant syntax validation
- Side-by-side comparison
Unix Timestamp
Convert Unix timestamps to human-readable dates and back. Auto-detects seconds vs milliseconds with UTC and local time display.
- Auto-detects seconds & milliseconds
- UTC and local time display
- Current timestamp button
URL Encoder
Encode and decode URLs with percent-encoding instantly. Two-way real-time conversion with RFC 3986 compliance.
- Two-way real-time encoding
- RFC 3986 compliant
- Error detection for malformed URLs
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes instantly. All four algorithms shown simultaneously with copy buttons.
- 4 algorithms at once
- Uppercase / lowercase toggle
- Hashes empty string on load
JSON ↔ YAML
Convert between JSON and YAML instantly. Edit either side and the other updates in real time with syntax validation.
- Two-way real-time conversion
- Instant syntax validation
- Smart clipboard paste detection
Regex Tester
Test and debug JavaScript regular expressions with live match highlighting. Supports g, i, and m flags.
- Live match highlighting
- g, i, m flag toggles
- Match count summary
JWT Generator
Build and sign JSON Web Tokens with a custom header, payload, and HMAC secret. Supports HS256, HS384, and HS512.
- HS256 / HS384 / HS512
- Custom header & payload
- Live generation in browser
UUID Generator
Generate UUID v4 values instantly. Copy individually or in bulk, customize formatting, and validate existing UUIDs.
- UUID v4 format
- Bulk generation
- Validate existing UUIDs
Case Converter
Convert text to lowercase, UPPERCASE, camelCase, snake_case, kebab-case, and more — all at once.
- 10 case formats at once
- Smart word splitting
- One-click copy per format
Text Diff
Compare two blocks of text line by line. Highlights additions, deletions, and unchanged lines. Supports unified and split view.
- Unified & split view
- LCS diff algorithm
- Ignore whitespace option