Free Online Developer Tools - Privacy First & 100% Client-Side
No server uploads. No API keys leaked. 100% Client-side processing for peace of mind.
Developer Utilities
15 toolsUUID Generator
Bulk generate v4 UUIDs
JSON Formatter
Validate & beautify JSON
Code Snap - Beautiful Code Screenshots
The ultimate Carbon alternative for developers. Support Retina export and glassmorphism background.
Cron Generator
Visual cron scheduler
One-to-One File Transfer
File transfer tool without installation
Base64 Converter
Text & Image encoder/decoder
Diff Checker
Compare text differences
Password Generator
Secure random passwords
Unix Timestamp
Convert epoch time to date
YAML to JSON
Convert YAML format to JSON format (runs locally in your browser)
JSON to YAML
Convert JSON format to YAML format (runs locally in your browser)
JSON to Code
Convert JSON to TypeScript, Go, Kotlin types instantly
Local SQL Analyzer
Analyze CSV/JSON/Parquet files
SQLite Viewer
Debug SQLite files locally
JWT Debugger
Securely decode JWTs offline
Image & Media
13 toolsSmart Compressor
Compress to specific size (MB)
Image Converter
WebP/PNG to JPG converter
HEIC to JPG
Convert iPhone photos to JPG
YouTube Thumbnail
Download 4K thumbnails
QR Code Generator
Customizable QR codes
Screen Recorder
Record screen with no watermarks
Offline Voice Recorder
Record audio locally (WebM)
Audio Converter - Offline Mode
Secure offline audio converter for MP3, WAV, FLAC & RAW
Video Splitter - Long to Short
Split long videos into short clips instantly. 100% offline, privacy-first
Image Watermark Tool
Add text or image watermark to photos. 100% offline, privacy-first
Image Watermark Remover (Simplified)
Remove edge watermarks or simple watermarks. 100% offline, privacy-first
WeChat 9-Grid Image Maker
Convert one image into 9-grid for WeChat Moments. 100% local processing.
Multi-Platform Cover Maker
Create video covers for all social platforms. Crop, split, and download locally. No upload required.
Why Choose KNothing?
Privacy First
Logic runs in your browser. No data is sent to our servers. Your API keys and content are safe.
Offline Capable
PWA enabled. Works without internet. Install it on your device for instant access.
Blazing Fast
Powered by WebAssembly and Nuxt 3 for near-native performance.
home.faq.title
home.faq.q1
home.faq.a1
home.faq.q2
home.faq.a2
share.title
share.desc