Free Online Calculators & Tools

66 tools for everyday tasks — free, browser-based, and private by design. Your tool data stays in your browser.

Featured tools

All 66 tools

Tip Calculator

Calculate tips and split bills easily.

JSON Formatter

Format, validate, and syntax-highlight JSON instantly.

Text Diff Checker

Compare two text blocks line by line in your browser.

Color Contrast Checker

Check WCAG contrast ratios for text and backgrounds.

Image Resizer

Resize JPG, PNG, WebP, and other images to exact pixel dimensions.

Start with a task

Pick a goal and get to a useful tool quickly.

Calculate

Solve everyday and technical problems.

scientific calculator percentage calculator aspect ratio calculator

Inspect & convert

Understand data without uploading it.

json formatter jwt decoder number base converter

Create & design

Generate useful code and visual output.

css gradient generator qr code generator color palette generator

Private by default for your inputs

Calculations and transformations happen in this browser tab. Analytics measures page visits only, never the numbers, files, or text you enter. Change that setting any time in the footer or on the privacy page.