免費線上工具

Convert astronomical units (AU) to light-years, parsecs, kilometers, meters, and miles. Enter any distance and get instant conversions with formulas. Free, browser-based.

Free WebP and AVIF batch compressor — optimize many images in your browser, compare size savings, and download a ZIP.

Combine multiple PDF files into one document in your browser, with drag-free reordering and instant download.

Free Simon-style memory sequence practice game — watch the pattern, tap it back, and beat your best score stored in your browser.

Convert HEX color codes to RGB and RGBA values with a live color preview.

Build a calm, practical positivity plan with thought reframes, short habits, and self-compassion prompts — not therapy, not toxic positivity.

Randomize experiment run order, assign samples to treatment groups, or shuffle replicate blocks. Fisher–Yates shuffle with optional seed for reproducible lab randomization. Free, browser-based.

Compute natural log (ln), common log (log₁₀), binary log (log₂), custom-base logarithms, and antilogs with change-of-base steps and verification.

Create layered CSS text shadows with live typography preview and copy-ready CSS, inline styles, and Tailwind classes.

Mole calculator free — convert between grams, moles, and particles using molar mass. Instant chemistry stoichiometry in your browser, no signup.

Convert numbers to and from scientific notation, e-notation, and engineering notation. Enter decimals (299792458), e-notation (1.23e-5), or 1.23 × 10^5 format. Get normalized scientific, Unicode superscript, engineering (×10³), and decimal forms. Adjustable significant figures. Free, browser-based.

Check whether text reads the same forwards and backwards, with options to ignore case, spaces, and punctuation.