Browse 11 Tool Categories

148 free online tools, organized by what you are trying to do. Every tool runs in the browser with no account and no install.

This page lists every category and every tool inside it, so you can scan the whole site at once rather than searching for a name you are not sure of. Each category heading links to an overview explaining what those tools do, how to choose between the similar ones, and the mistakes that come up most often.

The split between categories is by task rather than by technology. Some calculators appear under Health or Finance rather than Calculators because that is where people look for them, and a few tools are genuinely borderline — the color contrast checker sits under Developer Tools because it is usually used while building something, not while editing a photograph.

Calculators (24)

This section collects the calculations people look up rather than memorize: percentages and fractions, the statistics used in coursework, the trigonometry that turns up in a DIY measurement, and the kitchen and photography math that has awkward units baked into it.

Currency & Finance (26)

Mortgages, loans, savings, salary, tax, property and crypto: the calculations that decide what something actually costs over its full term rather than what the monthly figure suggests.

Developer Tools (21)

Formatters, encoders, decoders, generators and network lookups: the utilities you reach for mid-task and want to finish in five seconds without creating an account.

Text & Language (10)

Counting, converting, cleaning and analyzing text: the operations that are trivial to describe and tedious to do by hand on anything longer than a paragraph.

Image & Media (13)

Resizing, cropping, compressing, converting and generating images, plus QR codes and color utilities, all processed in your browser using the canvas API rather than on a server.

Weather & Environment (5)

Forecasts, air quality, UV index, sunrise and sunset, moon phase, elevation and the "feels like" calculations that turn temperature and humidity into something meaningful.

Data & Reference (5)

Reference lookups and conversions: country data, postal codes, time zones, distances, date codes and sizing charts.

Health & Fitness (11)

Calculators for energy needs, body composition, hydration, training and sleep: the numbers used to plan rather than to diagnose.

Education (10)

Grade calculation, study timing, and reference tools for chemistry, physics, electronics, music and language: the things looked up during coursework or a project.

Business (14)

Margin, markup, ROI, break-even, payment processor fees and the marketing metrics that get quoted in meetings: mostly small calculations that are easy to get subtly wrong.

PDF Tools (9)

Merge, split, rotate, compress, convert and annotate PDFs, every one of them processed entirely in your browser.

Looking for something specific?

The complete tool directory lets you search all 148 tools by name.