Solve technical challenges instantly with articles and tools
A technical resource site that fulfills developers' "want to know" and "want to try" needs in the shortest possible time. Deepen your knowledge with practical technical articles and support implementation with browser-based tools that require no registration. We provide a consolidated resource to accelerate daily development work, from front-end to back-end.
Purpose of this site
To answer the "How do I implement this?" or "I just want to check something" moments developers face, we've gathered technical knowledge and handy tools in one place. We provide an environment where you can shorten research time and focus on essential development work.
Who is it for?
For engineers who value efficiency in daily tasks, developers wanting to catch up on technology, and tech leads who want to perform quick verifications. Useful for everyone from beginners to veterans as an aid for technical decision-making and implementation.
Why is it useful?
Because reliable technical articles and instantly usable verification tools are paired, the transition from leaning to practice is smooth. All tools run locally, so you can verify with business data without worrying about security.
Difference from other sites
It's not just a collection of tools, nor just a blog media. It's a comprehensive platform for engineers that emphasizes the experience of "understanding with articles and trying with tools," pursuing professional-level quality and usability.
Introduction
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Create Infrastructure Diagrams in Your Browser: Auto-Generate Diagrams from Code
Use our Mermaid.js-based infrastructure diagram builder to visualize cloud and network configurations just by defining nodes and connections.
How to Auto-Generate ER Diagrams from SQL (DDL) and the Benefits of Doing So
Learn how to visualize your database design by auto-generating ER diagrams from DDL, such as CREATE TABLE statements.
Mastering Automation: Efficiency with GitHub Actions and Cron
Explore GitHub Actions for modern CI/CD and Cron for traditional scheduled tasks. Learn how to manage complex workflows and schedules without errors.
Optimizing Data Interoperability: Choosing Between JSON, CSV, and YAML
Understand the three dominant data formats in modern system development. Learn their strengths and how to seamlessly convert between them for better tool integration.
Development Story
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Generating QR Codes: Faster and Safer
Using Canvas API and node-qrcode to achieve real-time generation and privacy protection entirely within the browser.
Solving JSON to TypeScript via Recursion: The Strength of Zero Dependencies
Generate type definitions instantly from API responses. A behind-the-scenes look at a lightweight, high-speed implementation using recursive algorithms.
Secure JWT Verification in the Browser: A Security Engineer's Perspective
Handling sensitive tokens safely. Why we used the 'jose' library and local processing for our JWT tool design.
Safe Without Data Transmission: The Background of Our Browser-based Diff Tool
How we designed a private, high-speed text comparison tool using browser-side computing to prioritize user privacy.
Tools
Development & DevOps
8 items
GitHub Actions Visualizer
Visualize and build GitHub Actions workflow YAML with interactive diagrams in the browser.
SQL Formatter
Format and beautify SQL queries for various dialects (MySQL, PostgreSQL, etc.) instantly.
Visual SQL Builder
Construct complex SQL queries with SELECT, JOIN, and WHERE clauses using an intuitive visual GUI.
SQL → ER Diagram
Parse CREATE TABLE statements and automatically generate ER diagrams with relationships for visualization.
Curl Converter
Convert cURL commands to code in Python, Node, Go, Rust, and more.
Chmod Calculator
Calculate and convert Linux file permissions between octal and symbolic formats with a visual UI.
Cron Editor & Parser
Parse Cron expressions into human-readable format and calculate next execution times for schedule verification.
Infrastructure Diagram Builder
Create system architecture and network diagrams with a GUI. Generate Mermaid code and images instantly.
Data Conversion & Schemas
6 items
JSON Formatter
Pretty-print or minify JSON for quick validation of payloads and logs.
JSON → TypeScript
Generate TypeScript interfaces from JSON instantly for API responses and configs, including optional/null hints.
JSON → Zod
Infer Zod schemas from sample JSON for parsing or runtime validation and share contracts quickly.
JSON → OpenAPI
Generate OpenAPI component schemas from example JSON in the browser to prep review-ready drafts.
JSON ⇔ YAML
Paste JSON or YAML and convert both ways with copy helpers for config or docs handoffs.
CSV ⇔ JSON Converter
Convert between CSV and JSON formats with support for custom delimiters and headers.
Security & Cryptography
5 items
Base64 / 58 / 32
Switch tabs to encode or decode with any base in one place while comparing lengths and URL safety.
JWT Tool
Create and decode HS256-signed tokens in the browser without sending keys out of your session.
Hash & HMAC Generator
Generate SHA-1, SHA-256, SHA-512 hashes and HMAC signatures instantly in the browser for secure data verification.
JWKS Generator
Build RSA key pairs, publish public JWKS, and sign RS256 JWTs locally to rehearse key rotation.
UUID Generator
Generate UUIDv4 identifiers and copy instantly for tests or collision checks.
Text & Code Helpers
4 items
Markdown Table Generator
Create and edit Markdown tables visually with CSV import/export and column alignment controls.
Text & Code Suite
Count text, escape HTML/XML, minify CSS/JS, and generate passwords for quick publishing checks.
Regex Tester
Validate patterns, flags, and captured groups in one view to mirror production-like tests.
Diff Viewer
Visualize text changes with inline highlighting to confirm edits before commits or reviews.
URL & Network
4 items
URL Encode / Decode
Encode or decode URLs without leaving your browser to catch slug issues or encoding gaps.
URL Params → JSON
Turn query strings into JSON objects for quick inspection when debugging APIs or webhooks.
QR Generator
Turn any text or URL into a QR code and save as PNG for sharing Wi‑Fi setups or quick links.
QR Reader
Scan codes with the browser camera and decode locally without sending images to a server.
Design & UI
2 items
Date & Time
3 items
Time Zone Converter
Swap between any two time zones instantly (default UTC and JST) to sanity-check launch, meeting, or deploy times.
Time Units
Convert milliseconds through weeks at once and compare results for TTLs, delays, and retry windows.
UNIX Timestamp Converter
Convert UNIX timestamps (seconds or milliseconds) to UTC and local time instantly to validate logs and alerts.