免費線上工具
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
QML Formatter
Free online QML formatter — beautify or minify Qt Quick / QML code in your browser with readable indentation. No install.
Website Uptime Checker
Check if a website is online from the server. See HTTP status, response time, redirects, and key response headers.
pH Calculator
pH calculator free — find pH, pOH, and ion concentrations from [H⁺], [OH⁻], or strong acid/base molarity. Instant, no signup.
Protein Molecular Weight Calculator
Calculate protein molecular weight from amino acid sequence — average mass in Da and kDa with composition breakdown. Free, instant, browser-based.
Metronome
Free online metronome — set BPM, beats per measure, accents, and Play/Stop. Accurate Web Audio clicks in your browser. No signup.
Excel to CSV
Convert Excel spreadsheets (XLSX, XLS, ODS) to CSV in your browser, with per-sheet selection and delimiter options.
URL Encoder / Decoder
Encode or decode URL strings with encodeURI or encodeURIComponent, entirely in your browser.
Instagram Story Downloader
View and download public Instagram Stories without logging into Instagram on this site. Public accounts only.
Box Shadow Generator
Design layered CSS box shadows with live preview and copy-ready CSS, inline styles, and Tailwind classes.
Mortgage Calculator
Estimate monthly mortgage payments including principal, interest, taxes, insurance, PMI, and HOA.
How to Talk to Your Upset Girlfriend
Get a calm repair plan with empathy, accountability, and natural message templates — not pressure, guilt, or “winning.”