免费在线工具
405+ free online tools for PDF, images, SEO, developers, color, and productivity. Fast, browser-based, and private — no signup, no installs, no limits. Search above or browse by category below.
Total tools405Available free tools
Categories15Active categories
Most usedCSV to ExcelPopular right now
Recently addedInterval Music RepeaterNewest tool
Transform Generator
Compose CSS transform values for translate, scale, rotate, and skew with live preview and copy-ready CSS.
Serial Dilution Calculator
Plan serial dilutions with fold factors, transfer volumes, and concentration at each step. Find how many steps to reach a target, or set up CFU plate-count dilutions. Full table with log₁₀ values and lab procedure. Free, browser-based.
Instagram Photo Downloader
Download public Instagram photos and carousel slides. Save JPG/PNG from public post links.
Unit Conversion Practice
Free unit conversion practice tool — convert between km and mi, °C and °F, and more. Check answers with tolerance and see a worked step.
CSS Gradient Generator
Generate linear, radial, and conic CSS gradients with repeating options and copy-ready background, Tailwind, and inline styles.
Orbital Period Calculator
Calculate orbital period from altitude or radius using Kepler's third law. Presets for ISS, geostationary orbit, Moon, and Earth around the Sun. Free, browser-based.
CSS Formatter
Format and beautify CSS stylesheets with indentation, readable rules, and optional minification.
Determinant Calculator
Calculate the determinant of a square matrix up to 6×6 with step-by-step cofactor work.
Chemical Name Generator
Convert chemical formulas to names and names to formulas — ionic compounds, acids, hydrates, and common molecules. Free, instant, browser-based.
Git Ignore Generator
Build a .gitignore file by combining templates for languages, frameworks, editors, and operating systems.