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Practical guides for real tasks — written by the people building the tools on this site.
Showing 2,311–2,331 of 2,462 articles
✍️ Text & Writing
How to Add Strikethrough Text on Any Platform
Convert text into strikethrough or underline using Unicode combining characters, so it pastes as plain text anywhere, right in your browser.
🖊️ PDF Tools
How to Annotate and Mark Up a PDF Online
Draw, highlight, and mark up any PDF page directly in your browser, then save a flattened file that keeps your notes visible on any device.
🔒 Data & CSV
How to Anonymize a CSV Before You Share It
Mask, hash, or remove names, emails, and phone numbers from a CSV before sharing it with a vendor or teammate, with a practical look at what anonymizing actually fixes.
💵 Finance Calculators
How to Budget Your Paycheck With the 50/30/20 Rule
Break down a paycheck into needs, wants, and savings using the 50/30/20 rule so you know exactly how much is left over before the money disappears into spending.
🧳 Productivity
How to Build a Packing List You'll Actually Use
Generate a categorized packing checklist sized to your trip length and type, so you stop forgetting chargers, meds, or documents the night before you leave.
🧑🤝🧑 Productivity
How to Build an Org Chart From a Text List
Turn a simple text list of names and managers into a clean organizational chart, without dragging boxes around in a diagramming app for a small team update.
🔐 Security & Privacy
How to Build an SSH Config File for Multiple Hosts
Generate a multi-host SSH config file with aliases, hostnames, users, ports, and identity files, so you can type ssh prod instead of a long command every time.
📊 Math & Science
How to Calculate a Z-Score and Its Percentile
Calculate a z-score from a value, mean, and standard deviation, then convert it to a percentile with a plain-language interpretation for coursework or reports.
🏋️ Health & Fitness
How to Calculate Which Plates to Load on a Barbell
Figure out exactly which barbell plates to load on each side to hit a target total weight, with a visual plate stack, right in your browser.
🩺 Health & Fitness
How to Calculate Body Surface Area for Dosing
Calculate body surface area (BSA) from height and weight using the Du Bois, Mosteller, or Haycock formula, right in your browser, for dosing or clinical reference.
🔒 Security & Privacy
How to Calculate a Password's Entropy in Bits
Calculate a password's entropy in bits and an estimated offline crack time based on its real character set and length, not just a vague colored strength meter.
🧮 Math & Science
How to Calculate Permutations and Combinations
Calculate nPr permutations and nCr combinations from n and r with exact, arbitrary-precision results, right in your browser, for homework or probability work.
📉 Math & Science
How to Calculate Variance and Standard Deviation
Calculate mean, sample or population variance, and standard deviation from a pasted list of numbers, right in your browser, without a spreadsheet or manual formula.
📈 Finance Calculators
How to Calculate Your Annualized Investment Return
Calculate total gain and annualized XIRR return from multiple dated contributions, withdrawals, and a current value, right in your browser, no spreadsheet formula needed.
📏 Health & Fitness
How to Calculate Your Waist-to-Hip Ratio
Calculate your waist-to-hip ratio and WHO risk category from waist and hip measurements, right in your browser, without manually applying the WHO formula.
🎙️ Video & Audio
How to Change Your Voice Online for Free
Record a clip with your microphone and apply a robot, chipmunk, or echo effect in your browser, without installing voice-changing software or a Discord plugin.
📡 Network
How to Check a Server's Ping and Latency Online
Test round-trip time, packet loss, and latency to any website or server from your browser, without installing a desktop ping tool or opening a terminal.
🔍 PDF Tools
How to Check If a PDF Has a Real Text Layer
Check whether a PDF already has selectable, searchable text or is just a scanned image, page by page, before you rely on copy-paste or search working.
🔌 Network
How to Check If a Port Is Open on Your Server
Understand what an open TCP port actually means, why browsers can't check one directly, and how to think about port checking before you deploy a service.
📧 Text & Writing
How to Check if an Email Address Is Actually Valid
Validate an email address's syntax instantly, one address or a pasted list, and see the exact plain-language reason anything invalid fails before you send.
🎨 Design & Color
How to Check WCAG Color Contrast for Free
Check the contrast ratio between text and background colors for WCAG AA/AAA compliance, with live pass/fail results, before shipping a design that fails an audit.