↳ Utility tools
Everyday tools, zero setup.
Convert units, pick a random number, resize an image, calculate a tip or a percentage, and time your focus. Open the tool, get the answer, and move on, all in your browser.
Utility tools are the everyday helpers that do not fit a single category: converters, quick calculators, generators, and image tools. This set covers unit and color conversion, percentages, tips and discounts, BMI and calories, dates and ages, QR codes, random numbers, passwords, image resizing and compression, and a focus timer.
They share a simple promise. Each one does a single job instantly in your browser, with the result updating as you type and nothing to install or upload.
Reach for the converters when a value needs to change units, the calculators for quick everyday math, the generators when you need a code or a random pick, and the image tools to resize or shrink a picture without an editor.
All utility tools
16 toolsWhich utility tool should I use?
- Age CalculatorFind an exact age in years, months, and days.
- Aspect Ratio CalculatorWork out width or height for a target aspect ratio.
- BMI CalculatorCalculate body mass index from height and weight.
- Calorie & TDEE CalculatorEstimate daily calories and TDEE for your goals.
- Color Code ConverterConvert colors between HEX, RGB, and HSL.
- Date CalculatorAdd, subtract, and count the days between dates.
- Discount CalculatorFind the sale price and the amount you save.
- Image CompressorShrink an image file size without a visible quality drop.
- Image ResizerResize an image to exact dimensions in your browser.
- Password GeneratorCreate strong random passwords with a live strength meter.
- Percentage CalculatorWork out percentages, increases, and decreases.
- Pomodoro TimerRun focused work sessions with timed breaks.
- QR Code GeneratorCreate a QR code for a link, text, or contact.
- Random Number GeneratorGenerate random numbers in any range you set.
- Tip CalculatorSplit a bill and calculate the tip per person.
- Unit ConverterConvert length, weight, temperature, and more between units.
Frequently asked questions
What are utility tools?
Utility tools are everyday helpers that convert, calculate, generate, or transform something quickly. Common ones include a unit converter, percentage and tip calculators, a QR code generator, a password generator, and image resize and compress tools. ToolBook keeps them in one tab so you do not need a separate app for each.
Are these tools free to use?
Yes. Every utility tool here is free and runs in your browser, with results that update instantly as you change the inputs.
Are the image and other tools private?
Yes. The tools, including image resize and compress, process everything on the client side in your browser, so the files and values you use are never uploaded to a server.
Which tool converts between units?
The unit converter handles length, weight, temperature, volume, and more. For colors, the color converter moves between HEX, RGB, and HSL; for screen and video sizes, the aspect ratio calculator finds the missing dimension.
How do I make a strong password?
Use the password generator. It builds a random password with a live strength meter, so you can set the length and character types until it reports as strong. Longer passwords are stronger than short complex ones.
Can I use these tools on my phone?
Yes. The tools are built to work in any modern browser, on desktop or mobile, with no app to install.