D2D Utilities
100% In-Browser • Zero Server Uploads • Free Forever
Day-to-Day Developer & Productivity Suite
Fast, deterministic tools designed for real-world engineering workflows. All calculations run strictly in your local browser with instant response times.
JSON Formatter, Validator & Tree Viewer
Format, validate, repair, and explore JSON data client-side with syntax highlighting, 60 FPS Web Worker streaming, and interactive tree view.
Unicode-Aware Text Counter & Analyzer
Count words, characters, sentences, paragraphs, reading time, speaking time, and keyword frequency using native Intl.Segmenter.
Safe Regex Tester & ReDoS Worker Guard
Test regular expressions with real-time match highlighting, capture groups, and replacement previews protected by a 1000ms ReDoS worker guard.
Cron Expression Parser & Humanizer
Parse 5-part cron schedules into plain English, view field breakdowns, inspect the next 5 execution timestamps, and choose from common presets.
QR Code & Code 128 Barcode Generator
Generate high-resolution QR codes for text, URLs, and Wi-Fi networks, plus Code 128 barcodes with vector SVG and raster PNG downloads.
Multi-Scale GPA & CGPA Calculator
Calculate cumulative semester GPA across US 4.0 and 10.0 CGPA grading scales with customizable grade points and CSV export.
KaTeX LaTeX Equation Renderer & Visualizer
Render complex LaTeX mathematical formulas in real-time using fast client-side KaTeX with formula presets, display mode toggles, and SVG export.
JWT Inspector & SubtleCrypto Signature Verifier
Inspect JSON Web Tokens, evaluate claims, track expiration validity, and verify HMAC signatures locally via Web Crypto Subtle.
Bi-directional Tabular Data Converter
Convert between CSV, TSV, Markdown, JSON, and HTML tables with full RFC 4180 parsing, live cell editing, and instant file downloads.
Client-Side PDF Manipulator
Merge, split, extract, and rotate PDF documents entirely inside your browser memory. Zero file uploads, zero server compute.
Image Converter, Compressor & Resizer
Convert formats (PNG, JPEG, WebP), resize dimensions with aspect ratio lock, and adjust compression quality client-side via HTML5 Canvas.
Local Invoice Builder & PDF Engine
Create client-ready invoices with line items, tax math, and multi-currency formatting. Export vector PDFs locally with zero backend dependencies.