Free Online Tools for Developers
Powerful, fast, and free tools for developers, writers, and everyone.
Featured Tools
Most popular online utilities
JSON Formatter
Format, validate, and beautify your JSON data online for free.
DevBase64 Encoder/Decoder
Encode text to Base64 or decode Base64 to text instantly.
DevURL Encoder/Decoder
Encode or decode URLs and query parameters online.
DevWord Counter
Count words, characters, sentences, and paragraphs in your text.
TextCase Converter
Convert text between UPPERCASE, lowercase, Title Case, and more.
TextUnit Converter
Convert between different units of length, weight, temperature, and more.
CalcHash Generator
Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes from any text online.
DevColor Picker & Converter
Pick colors and convert between HEX, RGB, HSL, and RGBA formats instantly.
DevRegex Tester
Test and debug regular expressions with real-time matching and highlighting.
DevUnix Timestamp Converter
Convert Unix timestamps to human-readable dates and vice versa.
DevUUID Generator
Generate random UUIDs (v4) instantly. Bulk generate up to 100 UUIDs at once.
DevNumber Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal bases.
DevLorem Ipsum Generator
Generate placeholder Lorem Ipsum text for your designs and mockups.
TextMarkdown Preview
Write Markdown and preview the rendered HTML output in real-time.
TextPassword Generator
Generate strong, secure random passwords with customizable length and character types.
CalcPercentage Calculator
Calculate percentages easily: what percent is X of Y, X% of Y, and percentage change.
CalcJSON to CSV Converter
Convert JSON data to CSV format and CSV to JSON instantly. Free online converter for developers.
DevText Diff / Compare
Compare two texts side by side and see the differences highlighted. Free online diff checker.
TextCron Expression Generator
Parse, validate, and generate cron expressions with a visual editor. See next scheduled run times.
DevJWT Decoder
Decode and inspect JSON Web Tokens (JWT). View header, payload, claims and expiration status.
DevCSS Gradient Generator
Create beautiful CSS gradients with a visual editor. Copy the CSS code instantly.
DevHTML Entity Encoder/Decoder
Encode special characters to HTML entities or decode HTML entities back to text. Essential for web developers.
DevString Utilities
All-in-one string manipulation tool. Reverse, slugify, trim, sort lines, count characters and more.
TextColor Contrast Checker
Check WCAG color contrast ratios for accessibility. Verify AA and AAA compliance for text and background colors.
DevAspect Ratio Calculator
Calculate and convert aspect ratios for images, videos, and screens. Lock width or height to scale proportionally.
CalcQR Code Generator
Generate QR codes for URLs, text, Wi-Fi passwords, and more. Customize colors, size, and error correction level.
DevSEO Meta Tag Generator
Generate complete HTML meta tags for SEO, Open Graph, and Twitter Cards. Real-time SEO score and preview.
DevPomodoro Timer
A customizable Pomodoro productivity timer with work sessions, short breaks, long breaks, and session tracking.
CalcJSON Schema Generator
Generate JSON Schema from any JSON data. Auto-detect types, formats, and nested structures instantly.
DevAI Prompt Generator
Generate professional AI prompts with templates for coding, writing, data analysis, and marketing.
TextSQL Formatter
Format, beautify, and minify SQL queries online. Supports MySQL, PostgreSQL, SQLite, and standard SQL.
DevJSON to YAML Converter
Convert between JSON and YAML formats instantly. Bidirectional conversion for DevOps and configuration files.
DevImage to Base64 Converter
Convert images to Base64 data URIs for embedding in HTML and CSS. Drag and drop or paste Base64 to decode.
DevDate Formatter & Calculator
Convert dates between ISO 8601, Unix timestamps, and other formats. Calculate date differences easily.
CalcCSS to Tailwind Converter
Convert vanilla CSS properties to Tailwind CSS utility classes. Supports layout, spacing, typography, and more.
DevImage Compressor
Compress images online for free. Reduce file size while maintaining quality. Supports JPEG, PNG, and WebP formats.
MediaImage to PDF Converter
Convert images to PDF online for free. Combine multiple images into a single PDF document with custom page settings.
MediaImage Resizer
Resize images online for free. Set exact dimensions, choose output format, and download instantly. No upload to server.
MediaColor Palette Generator
Generate beautiful color palettes using color theory. Create complementary, analogous, triadic, and more harmony types.
DevCSV to JSON Converter
Convert CSV data to JSON format instantly. Supports custom delimiters, header options, and file upload. Free online converter.
DevPDF Merger
Merge multiple PDF files into one document online for free. Drag and drop to reorder pages. No upload to server.
MediaRandom Number Generator
Generate cryptographically secure random numbers. Supports custom ranges, dice rolls, and coin flips.
CalcMorse Code Translator
Convert text to Morse code and Morse code to text instantly. Play audio beeps and see visual signals.
TextText to Binary Converter
Convert text to binary code and binary to text online. Supports binary, octal, decimal, and hexadecimal encoding.
DevByte / Data Size Converter
Convert between bytes, KB, MB, GB, TB, and PB instantly. Supports both decimal (SI) and binary (IEC) systems.
CalcIP Address Lookup
Find geolocation, ISP, and other details for any IP address.
DevText to Speech
Convert text to speech using your browser's built-in voices.
TextEmoji Picker & Copy
Browse, search, and copy emojis instantly for any platform.
TextCharacter Counter
Count characters, words, sentences, and check platform limits instantly.
TextInvoice Generator
Create professional invoices in seconds. Free, no signup required.
CalcLatest Posts
Latest tech trends and tips
Social Media Character Limits in 2026: Complete Guide for Every Platform
Complete reference for character limits on Twitter/X, Instagram, LinkedIn, YouTube, Google Ads, and more. Plus a free character counter tool.
Free Invoice Generator for Small Business: Create Professional Invoices in 2026
Learn how to create professional invoices for free. No signup, no downloads. Our online invoice generator helps freelancers and small businesses get paid faster.
How to Merge PDF Files Online for Free β Complete Guide (2026)
Learn how to merge PDF files online for free using ToolBox Hub. This complete guide covers step-by-step instructions, browser-based benefits, common use cases, and how it compares to desktop software.