I built a free online toolbox with 80+ dev and productivity tools — here's what's inside

The Problem

I had 15+ browser bookmarks for small dev tools. JSON formatter here, Base64
encoder there, regex tester on some random site with 5 popups. Every time I
needed to convert a timestamp or decode a JWT, I was either searching Google
again or navigating to a site I half-remembered.

So I built WorkTool — a single, clean toolbox with 80+ tools. Here's what's inside.

Developer Tools (15 tools)

These are the ones I use most. All run client-side with zero file uploads:

JSON Tools

• JSON Formatter: Format, compress, validate JSON with syntax highlighting (Monaco editor)
• JSON Diff: Compare two JSON objects and highlight differences — great for API debugging

Encoding / Decoding

• Base64: Encode/decode text and files
• URL Encoder: encodeURIComponent / decodeURIComponent in a clean UI
• JWT Decoder: Parse header and payload, check expiration at a glance

Regex & Patterns

• Regex Tester: Real-time match highlighting with flag support (g, i, m, s)
• Cron Parser: Explain cron expressions in plain English — e.g. 0 9 * * 1-5 → "At 09:00 AM, Monday through Friday"

Conversion

• Timestamp Converter: Unix ↔ human-readable, with timezone support
• Color Converter: HEX ↔ RGB ↔ HSL with live preview
• Number Base Converter: Binary, octal, decimal, hex

Generators

• UUID Generator: v1/v4, single or batch
• Hash Generator: MD5, SHA1, SHA256, SHA512

Reference

• HTTP Status Codes: Full reference with descriptions
• SQL Formatter: Format SQL with dialect support
• Markdown Preview: Live render with GFM support

Image Tools (12 tools)

Privacy-first: client-side tools never upload files.

• Compress: Uses browser-image-compression — no server upload
• Format Convert: JPG/PNG ↔ WebP via Canvas API
• Crop: Interactive crop with aspect ratio lock
• Resize: Set exact dimensions or percentage
• Remove Background: AI-powered (server-side, deleted after 1h)
• Watermark: Text or image watermark via Canvas
• Image to Base64: FileReader API, instant
• EXIF Viewer: Read camera metadata with exifr
• Color Picker: Extract dominant colors from image
• GIF Maker: Combine images into animated GIF
• Image Diff: Visual comparison of two images
• SVG Optimizer: SVGO via WebAssembly

AI Tools (10 tools, DeepSeek API)

All use streaming output (SSE), so results start appearing immediately:

• Text rewriter
• Article summarizer
• Grammar checker
• AI translator
• Weekly report generator (give bullet points → get formatted report)
• Code explainer (paste code → get line-by-line explanation)
• Title generator
• Resume polisher
• Prompt builder
• Mind map generator (outputs Markdown outline)

Free users: 3 AI requests/day. Pro: 200/day.

Data Conversion (10 tools)

• CSV ↔ JSON (PapaParse)
• JSON ↔ Excel (SheetJS)
• XML ↔ JSON (fast-xml-parser)
• Markdown → HTML (marked.js)
• Unit converter (static conversion tables)
• Live currency converter (rates updated daily, cached in Redis)
• Byte converter
• Random data generator (faker-js, lazy-loaded)
• HTML table generator
• SQL → JSON

Productivity Tools (12 tools)

• QR code generator (custom colors, download PNG/SVG)
• Password generator (configurable length and charset)
• Word counter
• Pomodoro timer (Web Worker, works in background tab)
• Lorem Ipsum generator
• Remove duplicate lines
• Chinese Pinyin converter (pinyin-pro)
• Barcode generator (JsBarcode)
• Meeting countdown timer
• Invoice builder (HTML → PDF export)
• Color contrast checker (WCAG algorithm)
• Whiteboard (simple Canvas)

Document Tools (10 tools)

• PDF merge (pdf-lib, client-side)
• PDF compress (server-side API)
• PDF → Word (server-side API)
• Word → PDF (server-side API)
• PDF → Image (PDF.js)
• Image → PDF (pdf-lib)
• PDF split (pdf-lib)
• PDF OCR (server-side)
• PDF protect (pdf-lib)
• Excel → CSV (SheetJS)

Tech Stack

Framework:    Next.js 14 (App Router) + TypeScript
Styling:      Tailwind CSS + shadcn/ui
Database:     Neon (Postgres) + Drizzle ORM
Cache:        Upstash Redis (rate limiting, quota counting)
AI:           DeepSeek API (streaming via SSE)
Auth:         Auth.js v5 (email magic link)
Payment:      XorPay (CNY) + Creem (international)
Deploy:       Vercel

Privacy Design

This was important to me:

• Client-side tools (JSON formatter, Base64, image compress, etc.): nothing ever leaves the browser
• Server-side tools (PDF conversion, AI, remove background): files auto-deleted 1 hour after processing
• No file history: we don't store what you processed

What's Free vs Pro

Free: all tools available, 50 tool uses/day, 3 AI requests/day, 5MB file limit

Pro ($2.50/month): unlimited tool use, 200 AI requests/day, 100MB file limit,
batch processing, 30-day usage history

Check It Out

→ worktool.app: https://worktool.app?utm_source=devto&utm_medium=article&utm_campaign=launch

Would love to hear what tools are missing from your workflow. What's the one
browser-bookmark dev tool you use every week?

Built this as a side project. Happy to answer questions about any part of the implementation.