About Online Developer Tools
Modern software development involves a constant stream of small, repetitive tasks that sit outside the core code: validating a JSON payload from an API response, decoding a Base64 string embedded in a log file, testing a regular expression before adding it to production code, generating a UUID for a new database record, hashing a string to check data integrity, or decoding a JWT to inspect its claims during a debugging session. Each of these tasks traditionally required a command-line utility, a browser extension, or a standalone application. Our developer tools collection puts the most-used utilities directly in the browser — no installation, no backend, no data leaves your machine.
Privacy matters especially in a development context. Tokens, API keys, JSON with user data, and password patterns are all sensitive. Because every tool in this collection runs entirely client-side using browser JavaScript, your data never touches our servers — not even transiently. You can safely decode a JWT from a staging environment or hash a test password without worrying about exposure. This privacy-first approach also means the tools work offline once the page has loaded, which is handy when working in a restricted network environment or on a flight.
Available Tools
- JSON Formatter & Validator — paste minified or malformed JSON to get it indented, syntax-highlighted, and validated with line-level error reporting.
- Base64 Encoder — encode any text string to Base64, useful for HTTP Basic Auth headers, data URIs, and email MIME attachments.
- Base64 Decoder — decode Base64 strings back to their original plaintext.
- URL Encoder — percent-encode characters so a string can be safely embedded in a URL query parameter.
- URL Decoder — convert percent-encoded strings back to human-readable text.
- Regex Tester — test regular expression patterns against a block of text and see all matches with their positions and flags.
- Secure Password Generator — generate strong random passwords using the browser's cryptographically secure random number API, with configurable length and character sets.
- UUID v4 Generator — produce one or more RFC 4122-compliant v4 UUIDs using cryptographic randomness.
- Hash Generator — compute SHA-1, SHA-256, or SHA-512 hashes for any text input using the Web Crypto API.
- JWT Decoder — decode and inspect a JSON Web Token's header and payload; displays expiry, issuer, subject, and all claims without verifying the signature.
- QR Code Generator — create QR codes from any text or URL and download as PNG at sizes from 150px to 500px.
- My IP Address — detect and display your current public IPv4 address.
Who Uses These Tools?
Frontend web developers use the JSON formatter daily to inspect API responses and the Base64 encoder when constructing data URIs for inline images or fonts. Backend engineers and DevOps professionals use the hash generator to verify file checksums, validate password storage logic, or generate HMAC keys during local testing. Security researchers and penetration testers use the JWT decoder to inspect token claims and the regex tester to craft input validation patterns. Students learning web development use the URL encoder to understand how query strings work and the UUID generator to populate test databases without conflicts. QA engineers use the QR code generator to quickly produce scannable codes for mobile testing workflows.
Key Benefits
- Zero-install, zero-signup — open the page in any browser and every tool is ready immediately.
- Privacy-first — all processing runs in JavaScript inside your browser tab; nothing is sent to any server.
- Cryptographic quality — passwords and UUIDs use the browser's
window.cryptoAPI, the same source of entropy used by security libraries. - Offline capable — once the page is loaded, the tools continue to work without an active internet connection.
- Works on mobile — responsive layout adapts to phones and tablets for on-the-go debugging.