Developer toolbox

Choose a tool. Get it done.

Fast utilities for AI prompting and everyday web development. Each tool has its own focused page. Most tools process data locally; the website auditor checks public URLs through our server.

Built for everyday work

Useful tools across the development workflow

Format data, improve interfaces, inspect security-related values, and handle repetitive text tasks without sending content away.

Developer formatting JSON CSV and structured data in a browser tool

Data formatting

Work with JSON, CSV, Base64, URLs, and timestamps.

CSS design controls for gradients shadows colors and responsive interfaces

CSS and design

Create gradients, shadows, color combinations, and interface details.

Browser security utility showing hashes passwords tokens and privacy controls

Security and privacy

Generate passwords, inspect tokens, and create secure hashes locally.

Text productivity tools for email extraction case conversion and word counting

Text productivity

Extract, count, convert, encode, and prepare text efficiently.

Google Apps Script 100 Studio

Practice Apps Script methods with 100 lessons, simulated services and visible execution traces.

JavaScript 100 Learning Studio

Run, edit and understand JavaScript with 100 lessons, visual labs and project challenges.

Claude Code Launchpad

Learn Claude Code with 50 practical lessons, simulated terminal practice, prompt briefs and a downloadable project.

AI Model Router & Cost Optimization Lab

Test responses, compare routing strategies and forecast model costs.

AI Document-to-Data Automation Studio

Extract structured fields, verify sources, correct validation errors and export reviewed data.

AI Reliability & Evaluation Lab

Evaluate saved or live AI responses, inspect transparent checks and compare regression evidence.

RAG Knowledge Intelligence Studio

Import sources, explore chunk boundaries, retrieve exact passages and test a grounded knowledge pipeline.

AI Workflow Architect & Agent Orchestrator

Design, simulate, debug and evaluate AI workflows with visual nodes, approvals and ten runnable templates.

HTML5 Canvas Maze Workshop

Build a turn-based maze adventure through 50 lessons, a visual tile editor, keys, gates and patrolling enemies.

JavaScript Game Workshop

Create playable JavaScript games through 50 interactive lessons, editable rules and five mini projects.

JavaScript DOM Discovery Studio

Make pages come alive with 50 interactive DOM lessons, a live code workspace and five mini projects.

Vibe Coding Academy

Build with AI and understand your work through 50 self-guided lessons and five learning paths.

JSON Learning Studio

Learn JSON through 16 hands-on lessons with real syntax validation, a data tree, JSON Pointer inspection and repair exercises.

Vibe Coding Build Studio

Learn to plan, build, debug and review AI-assisted apps through 24 practical lessons and a hands-on project-brief workbench.

AI Skills Studio

Learn to use AI through 24 practical lessons, a prompt workbench, manual response comparisons and evidence-checking exercises.

JavaScript Build Studio

Learn JavaScript through 24 guided builds with editable code, real execution, changeable input data and practical project views.

Google Apps Script Build Studio

Learn built-in Google Apps Script services through 24 guided builds, editable scripts and interactive local Workspace simulations.

HTML & CSS Build Studio

Build four real websites through 24 guided HTML and CSS missions with editable code, live previews and checks of the actual browser output.

Web Accessibility Rescue

Rescue a fictional festival website through ten interactive accessibility repairs, real browser checks and short knowledge challenges.

CSS Motion Lab

Learn web animation with a visual keyframe studio, scrubbable timeline, easing comparisons, 12 lessons and six hands-on missions.

AI Context Lab

Learn to give AI the right information with source-card experiments, context budgets, 12 short lessons and eight practical missions.

Google Workspace Everyday Lab

Learn everyday Google Workspace tasks through 24 plain-language lessons and six friendly, interactive practice labs.

Web Debugging Escape Room

Restore a miniature web city through twelve real-browser repair challenges covering layout, accessibility and JavaScript logic.

⑂Productivity

Branching Scenario Studio

Build interactive learning journeys with a visual story map, images, quizzes, feedback and multiple endings.

AI Agent Builder Studio

Design visual agent workflows, simulate decisions, inspect approvals and test local tools without an API.

JSON Formatter & Validator

Format, minify, and validate JSON instantly in your browser.

CSS Gradient Generator

Build a polished linear gradient and copy production-ready CSS.

Unix Timestamp Converter

Convert Unix timestamps to readable dates and back again.

Text Case Converter

Convert text to title, sentence, camel, kebab, snake, or uppercase.

Regex Tester

Test regular expressions and inspect every match without sending data away.

◒Accessibility

Color Contrast Checker

Check WCAG contrast ratios for text and background colors.

URL Encoder & Decoder

Safely encode or decode URLs, query values, and text fragments.

Base64 Encoder & Decoder

Encode plain text to Base64 or decode Base64 back to text.

Word & Character Counter

Measure words, characters, sentences, lines, and reading time.

SEO Meta Tag Generator

Create essential title, description, canonical, and social meta tags.

CSS Box Shadow Generator

Design polished shadows with live controls and copyable CSS.

•••Security

Secure Password Generator

Generate strong passwords locally using browser cryptography.

Email Extractor

Find, clean, deduplicate, sort, copy, and download email addresses from pasted text.

UUID Generator

Generate one or many cryptographically random UUID v4 identifiers in your browser.

Hash Generator

Create SHA-256, SHA-384, or SHA-512 hashes from text using the Web Crypto API.

JWT Decoder

Inspect JWT header and payload data locally without uploading or verifying the token.

JSON to CSV Converter

Convert arrays of JSON objects into clean downloadable CSV data.

HTML Entity Encoder & Decoder

Encode text safely for HTML or decode HTML entities back into readable text.

CSS Formatter & Minifier

Beautify readable CSS or remove unnecessary whitespace for production use.

URL Parser & Query Inspector

Break a URL into its protocol, host, path, query parameters, and fragment.

URL Slug Generator

Turn titles and phrases into clean SEO-friendly URL slugs.

Aspect Ratio Calculator

Calculate image and video dimensions while preserving the original aspect ratio.

CSS Grid Builder

Build responsive auto-fit or fixed-column grids with a resizable preview and ready-to-copy CSS.

Flexbox Layout Builder

Explore alignment, wrapping, direction, and spacing with a live Flexbox layout preview.

Fluid Typography Calculator

Generate CSS clamp() font sizes that scale smoothly between your chosen viewport widths.

CSS Spacing Scale Generator

Create consistent linear or geometric spacing tokens for margins, padding, and gaps.

Color Palette & Shades Generator

Turn a brand color into ten useful tints and shades with exportable CSS variables.

Image Resizer & Compressor

Resize and compress JPEG, PNG, and WebP images locally, preview the result, and download.

SVG to CSS Background Converter

Encode SVG artwork as a CSS background-image data URL without uploading your source.

Placeholder Text Generator

Generate paragraphs, sentences, or an exact word count for layouts in plain text or HTML.

Robots.txt Generator

Build crawler directives, allowed exceptions, and sitemap references for your robots.txt file.

CSS Media Query Builder

Create responsive CSS queries with width ranges, orientation, and motion preferences.

AI Prompt Generator & Writing Guide

Build detailed prompts with task templates, context, examples, output formats, and a practical writing guide.

Prompt Checklist Reviewer

Inspect prompt structure with transparent local checks and create a revision brief.

AI Token & Cost Estimator

Estimate context usage and API costs using your own model limits and pricing.

AI Context Pack Builder

Organize reference material into a labeled context pack with sources and instructions.

AI Image Prompt Builder

Compose visual briefs with subject, composition, lighting, style, and exclusions.

Batch Image Optimizer & Converter

Resize and convert up to 20 images locally, compare results, and download a ZIP.

Website SEO & Broken Link Auditor

Audit public pages for SEO issues and broken links, with an exportable report.

CSV / JSON Data Cleaner & Converter

Clean, deduplicate, map columns, and convert CSV or JSON with a table preview.

Visual CSS Layout Builder

Design responsive Grid and Flexbox layouts with independent breakpoints and HTML export.

Text & Code Difference Checker

Compare text and code by line or word, normalize JSON, and download changes.

JSON Structure Explorer

Inspect nested JSON values, select JSON Pointer paths, and export a selected value.

List Comparison

Find shared items, differences and unique combinations across two lists.

UTM Campaign URL Builder

Build campaign links while preserving unrelated query parameters and fragments.

Unicode Text Inspector

Inspect code points, text normalization, character clusters and UTF-8 byte counts.

URL Query Editor

Edit ordered query parameters, including duplicate keys, without opening the URL.

JSON Lines Converter

Convert JSON arrays to JSON Lines and validate JSON Lines with precise line errors.

CSS Easing Playground

Shape a cubic-bezier curve, preview motion and export reusable transition CSS.

File Checksum Verifier

Calculate a local file hash and compare it with an expected SHA-256, SHA-384 or SHA-512 checksum.

JavaScript Array & Object Lab

Transform JSON with real JavaScript, visualize array pipelines and investigate object copies.

JavaScript Async Lab

Practice promises, compare request timing and predict event-loop output with interactive JavaScript exercises.

JavaScript DOM & Events Lab

Build interactive page behaviors and trace real browser events through guided JavaScript workshops.

JavaScript Quest

A beginner coding adventure with 15 missions, real JavaScript puzzles and saved progress.

HTML5 & Canvas Beginner Lab

Learn to draw and animate with 24 canvas lessons, live previews and a shape explorer.

Google Sheets Learning Studio

Practice formulas, create reusable function recipes and explore data through 50 guided Sheets lessons.

Google Workspace Learning Studio

Practice collaboration, sharing, search, meetings and workflows through 50 Workspace lessons.

Game Creation Lab

Build, tune, playtest and export a browser game with an interactive level designer.

Skybound Game Development Studio

Design a platformer, tune its physics, inspect playtests and export your playable game.

React App Builder Lab

Build a task board, experiment with React state and components, and export your working app.

TypeScript Confidence Lab

Check TypeScript in your browser, explore type narrowing and generate API data validators.

Node.js Backend Lab

Experiment with task API requests, visualize asynchronous work and download a tested Node server.

CSS Layout Playground

Design responsive Flexbox and Grid layouts, inspect dimensions and export working HTML and CSS.

Regex Learning Lab

Test regular expressions, inspect captures, preview replacements and practice pattern challenges.

Web Performance Lab

Model loading dependencies, compare scenarios and plan a measurable website improvement.

Canvas Game Academy

Design a platformer, explore Canvas drawing and collision systems, and export your game and source.

AI Learning Lab

Practice prompting, evidence review and classifier decisions with a downloadable learning workbook.

AI Prompt Builder Lab

Build, refine, save and test useful prompts with 120 templates and a local prompt library.

Debugging Detective Lab

Practice debugging with runnable cases, a trace explorer and a reproducible bug-report builder.

Vibe App Builder Studio

Plan, customize, test and export a real browser app from nine working templates.