All-in-One Toolbox
A collection of fast, free, and privacy-focused online tools, including text processing, image editing, file conversion, and programming development and more. No download required, use instantly to boost productivity.
Why Choose DevToolBox?
Built with modern web technologies for the best user experience
Privacy First
Your data never leaves your device. All processing happens locally in your browser using client-side JavaScript. No servers, no tracking, no data collection - ever.
Lightning Fast
Get instant results with zero server delays. No waiting, no loading spinners. Works perfectly offline once loaded, so you can use tools anywhere, anytime.
100% Free Forever
All tools are completely free with no hidden costs, premium tiers, or paywalls. No ads cluttering your workspace. No credit card required. Just pure functionality.
Easy to Use
Clean, intuitive interface designed for everyone. No manuals needed. Responsive design works flawlessly on desktop, tablet, and mobile devices.
All-in-One Toolbox
Everything you need in one place. From data encoding to color picking, hash generation to JSON formatting - access dozens of tools without switching between websites or apps.
Always Available
No server downtime or maintenance windows. Since everything runs in your browser, tools are available 24/7/365. Bookmark and use anytime you need.
Popular Tools
Powerful tools that run entirely in your browser. No servers, no tracking, just pure functionality.
Free Online URL Parameters Parser & Formatter
Free online URL parameter parser and formatter. Parse, decode, and analyze query strings instantly. No signup - 100% free, private, works offline for API development.
Free Online CSV Viewer - View & Analyze CSV Files Instantly
Free online CSV viewer to open, view and analyze CSV files in browser. No installation needed. Support large files, search, filter, sort and export. Paste CSV data or upload files. 100% secure and private.
Free Online Daily Water Intake Calculator
Free online water intake calculator. Calculate your personalized daily hydration needs based on weight, activity, and climate. No signup - 100% free and private.
Free Online Compound Interest Calculator
Free online compound interest calculator. Calculate investment growth with regular contributions and compound returns. No signup - 100% free and private.
Free Online URL Batch Generator
Free online URL batch generator with sequential numbering and customizable patterns. No signup required - 100% free, private, and works offline. Perfect for test URLs, SEO testing, and web scraping preparation.
Free Online Font Preview Tool - Compare Fonts Instantly
Free online font preview and comparison tool. Preview and compare fonts with custom text instantly. No signup required - 100% free, private, and works offline. Perfect for typography design and font selection.
Free Online Altitude Calculator - Real-time GPS Elevation
Free online altitude calculator with real-time GPS. Check your current altitude and elevation instantly - shows height above sea level, coordinates, and accuracy. No signup required - 100% free, private, and works on all devices.
Free Online Photo Book Maker - Create Albums Instantly
Free online photo book maker. Create stunning photo albums in minutes with drag & drop editing. No signup required - 100% free, private, export print-ready PDF.
Free Online JSON to CSV Converter
Free online JSON to CSV converter. No signup required, 100% free. Transform JSON arrays and objects into CSV files instantly with customizable delimiters. Works offline, completely private.
Free Online Video Player - Play MP4, WebM, AVI & More
Free online video player supporting MP4, WebM, AVI, MOV formats. No signup required, 100% free. Play videos with full controls and speed adjustment. Works offline, completely private.
Free Online TI-84 Calculator - Graphing Calculator Simulator
Free online TI-84 Plus CE graphing calculator simulator. No download, no signup required, 100% free. Plot graphs, solve equations, use statistical functions. Works offline, completely private.
Free Online Phone to VCF Converter - Batch Import Contacts
Free online phone to VCF converter for batch importing contacts. No signup required, 100% free. Convert phone numbers to vCard format with carrier detection. Works offline, completely private.
What Users Say
Trusted by users worldwide
Sarah Chen
Full Stack Developer
DevToolBox has become an essential part of my daily workflow. The JSON formatter alone saves me hours every week. Love that everything runs locally!
Michael Rodriguez
Backend Engineer
Finally, a tool collection that respects privacy! No more uploading sensitive data to random websites. The Base64 encoder is incredibly fast and reliable.
Emily Watson
Frontend Developer
Clean UI, lightning-fast performance, and works offline. The color picker is my go-to tool for design work. Highly recommended!
David Kim
DevOps Engineer
The hash generator and UUID tools are perfect for my automation scripts. Being able to use them offline during deployments is a game-changer.
Sarah Chen
Full Stack Developer
DevToolBox has become an essential part of my daily workflow. The JSON formatter alone saves me hours every week. Love that everything runs locally!
Michael Rodriguez
Backend Engineer
Finally, a tool collection that respects privacy! No more uploading sensitive data to random websites. The Base64 encoder is incredibly fast and reliable.
Emily Watson
Frontend Developer
Clean UI, lightning-fast performance, and works offline. The color picker is my go-to tool for design work. Highly recommended!
David Kim
DevOps Engineer
The hash generator and UUID tools are perfect for my automation scripts. Being able to use them offline during deployments is a game-changer.
Lisa Anderson
Software Architect
I've tried many online tool collections, but DevToolBox stands out with its privacy-first approach and modern interface. The tools just work!
James Thompson
Mobile Developer
Great collection of tools that I use daily. The URL encoder and JSON formatter are particularly useful. No ads, no tracking - just pure functionality.
Alex Martinez
Security Engineer
As a security engineer, I appreciate tools that don't send data to external servers. The hash generator is perfect for quick verification tasks during code reviews.
Rachel Green
UI/UX Designer
The color picker tool is incredibly useful for my design work. Being able to convert between HEX, RGB, and HSL instantly saves so much time. The interface is intuitive too!
Lisa Anderson
Software Architect
I've tried many online tool collections, but DevToolBox stands out with its privacy-first approach and modern interface. The tools just work!
James Thompson
Mobile Developer
Great collection of tools that I use daily. The URL encoder and JSON formatter are particularly useful. No ads, no tracking - just pure functionality.
Alex Martinez
Security Engineer
As a security engineer, I appreciate tools that don't send data to external servers. The hash generator is perfect for quick verification tasks during code reviews.
Rachel Green
UI/UX Designer
The color picker tool is incredibly useful for my design work. Being able to convert between HEX, RGB, and HSL instantly saves so much time. The interface is intuitive too!
Tom Wilson
Data Engineer
I work with a lot of encoded data and APIs. The Base64 and URL encoder tools are lifesavers. Fast, accurate, and no need to worry about data privacy issues.
Nina Patel
QA Engineer
Testing APIs requires a lot of data manipulation. DevToolBox has all the tools I need in one place. The JSON formatter with validation is particularly helpful for debugging.
Chris Johnson
Tech Lead
I've recommended DevToolBox to my entire team. It's become our go-to resource for quick data transformations. The fact that it works offline is a huge plus during travel.
Sophie Laurent
API Developer
Working with webhooks and API integrations means dealing with lots of encoded data. These tools are exactly what I need - simple, fast, and trustworthy. No bloat, just functionality.
Tom Wilson
Data Engineer
I work with a lot of encoded data and APIs. The Base64 and URL encoder tools are lifesavers. Fast, accurate, and no need to worry about data privacy issues.
Nina Patel
QA Engineer
Testing APIs requires a lot of data manipulation. DevToolBox has all the tools I need in one place. The JSON formatter with validation is particularly helpful for debugging.
Chris Johnson
Tech Lead
I've recommended DevToolBox to my entire team. It's become our go-to resource for quick data transformations. The fact that it works offline is a huge plus during travel.
Sophie Laurent
API Developer
Working with webhooks and API integrations means dealing with lots of encoded data. These tools are exactly what I need - simple, fast, and trustworthy. No bloat, just functionality.
Frequently Asked Questions
Everything you need to know about DevToolBox