Dev Tools
Developer tools that just work
A growing set of everyday utilities — format JSON, decode a JWT, test a regex, diff two files. Everything runs 100% in your browser: nothing is uploaded, nothing is logged, and it all works offline once loaded.
PDF Tools
Merge, split, organize, and create PDFs — no upload.
Image Tools
Convert, compress, resize, and crop images locally.
JSON Formatter
Format, validate, and minify JSON with clear error messages.
Base64 Encode / Decode
Convert text to and from Base64, with URL-safe support.
JWT Decoder
Decode a JSON Web Token and inspect its header and payload.
URL Encode / Decode
Percent-encode or decode URLs and query components.
UUID Generator
Generate random v4 UUIDs in bulk, one click to copy.
Hash Generator
Compute SHA-1, SHA-256, SHA-384, and SHA-512 hashes of any text.
Timestamp Converter
Convert between Unix timestamps and human-readable dates.
Regex Tester
Test regular expressions live with match highlighting and groups.
Diff Checker
Compare two blocks of text and see the differences line by line.
Case Converter
Convert text between camelCase, snake_case, kebab-case, and more.
Color Converter
Convert colors between HEX, RGB, and HSL with a live preview.
Lorem Ipsum Generator
Generate placeholder paragraphs, sentences, or words.
Cron Expression Parser
Explain a cron schedule in plain English and see its next runs.
JSON to TypeScript
Generate TypeScript interfaces from any JSON object.
Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal.
Word & Character Counter
Count words, characters, sentences, and reading time instantly.
Slug Generator
Turn any title into a clean, URL-friendly slug.
LinkedIn Profile Enhancer
Analyze and improve your LinkedIn About, Headline, and Experience bullets.
Free online developer tools
This is a collection of fast, no-nonsense utilities for developers — the everyday tasks you reach for while coding: formatting and validating JSON, encoding and decoding Base64, decoding a JWT, testing a regular expression, diffing two files, generating UUIDs and hashes, converting timestamps and colors, and more. Each tool has its own page with usage tips and answers to common questions.
Every tool runs entirely in your browser. Your input is never uploaded to a server, never logged, and never leaves your device — so you can safely work with API responses, tokens, and other sensitive data. Because there is no backend, the tools are instant and keep working even offline once the page has loaded.
No sign-up, no ads interrupting the tool, and no limits. Bookmark this page as your developer toolbox, and pair it with our cheatsheets and learning tracks when you need a quick reference or a deeper explanation.