Free Online Tools for Everyday Work
Simple, fast and private tools for developers, designers and businesses.
Explore the tools
Every tool runs entirely in your browser — no sign-up, no data leaves your device.
Color Palette Generator
Generate harmonious 5-color palettes with HEX, RGB and HSL values, lock your favorites, and copy with one click.
Open toolJSON Formatter
Format, validate and minify JSON instantly in your browser, with precise error locations for invalid input.
Open toolROI Calculator
Calculate return on investment, net profit and total investment in six currencies with a clear worked example.
Open toolCompound Interest Calculator
Project how savings or investments grow with monthly contributions and compounding, complete with a year-by-year chart.
Open toolWhy Toolzen
Private by default
Every calculation and conversion happens locally in your browser. We never see your inputs.
No friction
No accounts, no installs, no paywalls. Open a tool and start working immediately.
Always growing
Toolzen is a small, independent project that adds new tools over time based on what people actually need.