D2D Utilities
Day-to-Day Developer Utilities • 100% In-Browser • Zero Server Uploads
Day-to-Day Developer & Productivity Utilities
Fast, deterministic tools for your day-to-day workflow — from JSON and regex to PDF and invoices — with zero cloud fees and zero tracking.
JSON Formatter & Validator
Format, validate, and inspect JSON with collapsible Tree View and Web Worker offloading.
Unicode Text Counter
Accurate word, character, and sentence counting using native Intl.Segmenter API.
Safe Regex Tester
Test RegExp with capture groups breakdown and 1,000ms ReDoS Web Worker timeout protection.
Cron Expression Parser
Parse 5-part cron schedules into natural language with next 5 execution timestamps.
QR & Barcode Generator
Generate customizable QR codes and Code 128 barcodes with vector SVG/PNG export.
Multi-Scale GPA Calculator
Compute semester and cumulative GPA across US 4.0 and 10.0 scales with weighted credits.
LaTeX Equation Renderer
Render mathematical formulas client-side with KaTeX and export as SVG/PNG.
JWT Inspector & Verifier
Inspect JSON Web Tokens with SubtleCrypto HMAC SHA-256 signature verification.
Tabular Data Converter
Convert between CSV, TSV, Markdown, JSON, and HTML with RFC 4180 parsing and editable grid.
Client-Side PDF Manipulator
Merge, split, and rotate PDF pages in-memory using pdf-lib without uploading to any server.
Image Converter & Compressor
Convert and compress images (PNG, JPEG, WebP) with aspect ratio lock using HTML5 Canvas.
Local Invoice Builder
Create multi-currency invoices with dynamic line items and generate vector PDFs in browser.