⚙️ Free Developer Tools
The small utilities you reach for a dozen times a week. All of them run locally in the browser — your JSON, your tokens, and your passwords never leave the machine you are sitting at.
Split a File
Break a large file into numbered pieces small enough to email or upload — and joinable again without any tool.
Join Split Files
Reassemble .001 and .part pieces into the original file, with the order detected and missing pieces flagged.
Random File Generator
Generate a dummy file of an exact size, random bytes or zeros, for testing upload limits and storage.
JSON Formatter & Validator
Format, minify, and validate JSON online with instant error messages and quick stats.
Base64 & URL Encoder/Decoder
Encode and decode text as Base64 or URL-safe strings, with full UTF-8 support.
Text Diff Checker
Compare two texts and see exactly what was added, removed, or changed, line by line.
Case Converter
Convert text between UPPERCASE, Title Case, camelCase, snake_case, kebab-case and more.
Color Contrast Checker
Check text and background colors against WCAG AA/AAA accessibility standards.
Password Generator & Strength Checker
Generate cryptographically secure passwords and check the strength of an existing one.
How to get the most out of these
These are deliberately small: each does one thing you would otherwise script, search for, or do badly by hand. The JSON formatter validates with the browser's own parser, the password generator uses the cryptographic randomness your password manager uses, and the diff runs the same algorithm family as Git. Nothing here is a toy version of the real thing - for these narrow jobs, this is the real thing.
Local execution matters most in this category, because the things developers paste are the things that must not leak: API responses full of customer data, tokens, connection strings, passwords. Every tool on this page works offline once loaded. If you are ever unsure, open the network tab and watch - nothing leaves.
The limits are the flip side of the smallness: no JSON repair, no diff for binary files, no password vault. When a job outgrows the tool, the tool's own page says so and points at what to use instead.