Free Online Tools for Developers —
JSON, UUID, CSS, Image & 112+ More
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- 112+ Tools
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- 45+ Articles
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Popular Tools
View all tools →Character Counter
Count characters, words, lines, paragraphs, and reading time in real time. Includes Twitter/X, Instagram, and LINE character limit bars.
JSON Formatter & Validator
Format, validate, and beautify JSON in real time. Syntax highlighting, error line numbers, copy and download supported.
CSS Minifier
Minify CSS by removing comments, whitespace, and unnecessary characters. Shows compression percentage.
Meta Tag Generator
Generate all essential meta tags — title, description, OGP, Twitter Card, robots, canonical — from a simple form. No signup required.
UUID Generator
Generate UUID v1 or v4 with one click. Supports bulk generation and CSV export.
QR Code Generator
Generate QR codes for URLs, text, or any content. Custom colors and size. Download as PNG.
Browse Tools by Category
All categories →- Character Counter — Count Characters, Words & More
- Word Counter — Count Words & Characters Online
- Remove Line Breaks — Clean Up Copied Text Instantly
- Text Diff Checker — Compare Two Texts Side by Side
- JSON Formatter & Validator — Beautify JSON Online
- JSON Minifier — Compress JSON Online
- CSS Minifier — Compress CSS Files Online
- JavaScript Minifier — Compress JS Code Online
- URL Encoder & Decoder — Percent-Encode URLs Online
- URL Decoder — Percent-Decode URLs Online
- Base64 Encoder & Decoder — Encode or Decode Instantly
- Base64 Decoder — Decode Base64 Strings Online
- UUID Generator — Generate UUID v1/v4 in Bulk
- Random String Generator — Custom Length & Character Set
- Hash Generator — MD5, SHA-1, SHA-256, SHA-512
- QR Code Generator — Create QR Codes for URLs & Text
- Meta Tag Generator — SEO, OGP & Twitter Card Builder
- Meta Tag Checker — Analyze URL Meta Tags
- OGP Checker — Preview How Your URL Looks on Social Media
- SERP Preview — See How Your Page Looks in Google Search
- HTTP Headers Checker — Inspect Response Headers
- URL Parser — Break Down URL Components
- Password Strength Checker — Test Your Password Security
- IP Address Lookup — Find Your Public IP & Location
- Image Compressor — Compress PNG, JPEG & WebP Online
- Image Resizer — Resize Images by Pixel Dimensions
- PNG to JPG Converter — Convert PNG to JPEG Online
- JPG to PNG Converter — Convert JPEG to PNG Online
Developer Guides & Tutorials
View all articles →ISO 8601 Complete Guide: Date & Time Format Explained with Examples
Everything about ISO 8601 — the YYYY-MM-DDTHH:mm:ssZ format, timezone offsets (Z vs +00:00…
Cron Expression Complete Guide: Syntax, Patterns & Cloud Environments
Everything you need to know about Cron expressions — the five-field syntax, special charac…
JSON to TypeScript: Auto-Generate Interfaces from API Responses
How to convert JSON to TypeScript interfaces automatically — the type mapping rules, how t…
Barcode Types Explained: CODE128, EAN-13, UPC-A & When to Use Each
A practical guide to 1D barcode formats — how CODE128, EAN-13, EAN-8, and UPC-A differ, ho…
Word & Character Counter Guide: Limits for Twitter, Instagram, SEO & More
How to count characters and words for social media, SEO, and writing. Includes character l…
How to Create Strong Passwords: Length, Complexity & Passphrase Best Practices
What makes a strong password — length requirements, character types, passphrase vs random …
About Devryo
A free online toolbox for developers, designers, and learners. JSON formatting, CSS minification, UUID generation, image resizing and 112+ more tools — all running in your browser with no installation or sign-up required. Your data never leaves your device.