Developer tools
The small tools you open ten times a day: format a payload, decode a JWT, sanity-check a regex — without pasting production data into a random website.
- Runs in your browser
- Nothing uploads
- No account, no tracking
- Free — always
Paste anything — a webhook payload, a config, a copied fetch response. We'll indent it, sort the keys, and tell you exactly where the missing comma is.
Turn text or files into Base64 and back. URL-safe option and a one-click file-to-data-URL helper.
Paste a token to see header, payload and signature. The token never leaves your browser, so it's safe for prod secrets.
Write patterns and see matches highlight live. Tune flags, inspect capture groups, and throw ugly patterns at it safely — ReDoS-guarded.
Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes from text or any file — and verify a download with one paste.
Turn Unix epoch timestamps into human dates and back. Seconds or milliseconds, your timezone or UTC.
Turn CSV into JSON or JSON into CSV. Auto-detect delimiter, preview the result and download the file.
Explain any 5-field cron expression in plain English and preview the next upcoming runs.
Check one email or a whole list for valid syntax, with helpful typo suggestions for popular domains.
Generate SEO, Open Graph and Twitter Card meta tags with live Google and social previews.
Build a clean robots.txt with custom rules, sitemap URLs and tested presets for WordPress and more.
Visual file-permission builder — tick boxes to get octal, symbolic and a ready-to-paste chmod command.
Beautify SQL queries for PostgreSQL, MySQL, SQLite, T-SQL and more. Pick indent and keyword case.
Convert text to binary and back — full UTF-8 support including emoji, with optional byte spacing.
Calculate IPv4 subnet, mask, broadcast, host range and class from any IP and CIDR prefix.
Paste any User-Agent to see the browser, version, engine, OS and device — perfect for bug reports.
URL, HTML entities and hex encode/decode in one tool — bulk friendly and offline.
Drag two handles to design CSS easing curves with a live animation preview — copy ready-to-paste cubic-bezier().
Visual flex container playground — tweak direction, alignment, gap and per-item flex, then copy production-ready CSS.
Design a schema and generate up to 1,000 realistic mock records — names, emails, dates, UUIDs and more.
Live GitHub-flavored Markdown editor with split preview, themes, table of contents, autosave and HTML export.
Two-way HTML ↔ JSX with class→className, inline style objects, self-closing tags and SVG attribute fixes.
Shrink SVG files up to 80% smaller — strip editor junk, comments and unused IDs while keeping the visual identical.
Minify JavaScript with Terser or pretty-print it for readability. Mangle names, drop comments and see how much smaller it gets.
Compress CSS to the smallest valid form or beautify with one declaration per line and clean indentation.
Encode text to HTML entities — named, decimal or hex — or decode entities back into normal text and emoji.
Paste any JSON and get clean TypeScript interfaces — optional readonly, optional fields and array merging.
Convert a cURL command into fetch, axios, Python requests, PHP, Go or Node — runs entirely in your browser.
Generate 2FA / TOTP codes from a secret. Live 30-second countdown and otpauth:// QR code — keys stay on your device.
Turn code into beautiful screenshots with syntax highlighting, window chrome and gradient backgrounds. Export PNG.
Generate a strict Zod v3 schema from any JSON sample — optionals, enums for repeated strings and clean reusable definitions.
Inspect a .har file — requests, status, sizes, slowest hits and MIME breakdown — without uploading. HAR files contain cookies and auth headers, so privacy matters.