29 free tools · No login · Client-only
Free online developer tools
Everyday developer utilities without the ad-stuffed pages or the upload step: format and validate data, test regular expressions, diff text, decode tokens, convert configs, and handle images and PDFs locally. Your input stays on your machine because there is no server to send it to.
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Unit Converter
Convert data, electrical and physical units, and see every unit at once instead of picking one
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Punctuation & Typography Fixer
Strip the curly quotes, em dashes, and invisible spaces that word processors sneak into your text
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Case Converter
Convert case and run the line operations you always need - trim, dedupe, sort, number, wrap - in one pass
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Config Format Converter
Convert config between JSON, YAML, TOML, and .env - instantly, in your browser, offline
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Markdown Table Generator
Build a markdown table in a spreadsheet-style grid - then copy it as Markdown, CSV, or HTML
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PDF Merger
Drop multiple PDFs, drag to reorder, type page ranges per file, merge to one PDF - all in your browser.
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WebSocket Tester
Connect to any WebSocket or Server-Sent Events endpoint from your browser, see frames stream live, measure latency, send messages, validate JSON inline.
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Word Counter
Paste any text, see words, characters, sentences, paragraphs, reading time, reading level, and the top-10 most-used words - live as you type.
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HTML Viewer
Paste HTML, see it rendered live in a sandboxed preview - resize the split, simulate phone/tablet/desktop, catch JS errors.
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Base64 Encoder & Decoder
Encode/decode Base64, URL encoding, HTML entities, and hex - four encodings in one tool
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Hash Generator
Generate MD5, SHA-1, SHA-256, SHA-512, and HMAC hashes from text or files
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Code to Image
Turn code into beautiful shareable images with syntax highlighting and gradient backgrounds
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Color Toolkit
Extract dominant colors from images and convert between HEX, RGB, HSL, and CMYK
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CSS Button Generator
Design and export custom CSS buttons with gradients, shadows, and hover effects
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CSV to JSON Converter
Parse CSV files or pasted text into JSON with automatic type detection and edge-case handling
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Mock Data Generator
Generate realistic fake datasets as JSON or CSV for testing and prototyping
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CSS Gradient Generator
Generate glassmorphism panels and mesh gradients with live preview and copy-ready CSS
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Image Compressor
Compress JPEG, PNG, and WebP images client-side with target size and dimension controls
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JSON Formatter & Validator
Paste raw JSON to format, colorize, validate, and minify instantly
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JWT Decoder
Decode JWT header, payload, and signature - fully client-side, never transmitted
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Password Generator
Generate cryptographically random passwords and human-readable passphrases
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QR Code Generator
Generate styled QR codes for URLs, WiFi, contacts, and more - with logo embed
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Diff Checker
Compare two text blocks or code files and highlight exact additions and deletions
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Cron Expression Generator
Write, validate, and understand cron expressions with next-run previews
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Graphing Calculator
Plot a function, then actually ask questions about it - slope, area, roots, turning points
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Markdown Visualizer
Live Markdown editor with split preview, word count, and raw HTML export
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Regex Tester
Test regular expressions against sample text with live match highlighting
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HTML to Markdown Converter
Paste rich text or HTML → clean Markdown, copy in one click
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Unix Timestamp Converter
Unix ↔ datetime - relative time, ISO / RFC / local formats, live clock
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For informational purposes only. Not financial, medical, or legal advice. You are solely responsible for how you use these tools.