Guides
Plain-English explainers and how-tos, each paired with a free tool you can use right away — no sign-up, nothing uploaded.
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TextWhy Plain-Text Notes Beat the Fancy AppThe best note-taking system is the one you actually open. Why a plain, instant, distraction-free notepad captures more than any feature-packed app — and how to make capture frictionless.HealthWhat Is a Calorie, Really? (And How to Read a Nutrition Label)A calorie is a unit of energy — but the "calorie" on your food label isn't the one from science class. What the number means, why fat has more than sugar, and the label trap that multiplies it.Date & TimeTime Blocking: Schedule Your Day, Not Just Your To-Do ListA to-do list tells you what to do; it never tells you when. Time blocking assigns every task a slot on the clock — the quiet method behind people who somehow get deep work done.Date & TimeThe Pomodoro Technique: Why 25-Minute Sprints Beat MarathonsThe simple timer method that turns a vague, dreaded task into a series of winnable rounds — how it works, why the breaks matter, and how to adapt the 25/5 rhythm to your own focus.TextSocial Media Character Limits: The 2026 Cheat SheetEvery character limit that matters — X, Instagram, TikTok, LinkedIn, YouTube, plus the SEO title and meta-description lengths — and why writing to the limit beats writing past it.PDFHow to Shrink a PDF So It Actually SendsThe email bounced because your PDF is 30 MB. Why PDFs balloon, what the real attachment limits are, and how to get under them without turning your document into mush.GeneratorsHow to Run a Fair Random Giveaway (Without the Accusations)Picking a winner at random sounds easy until someone cries foul. How to run a giveaway that is fair, looks fair, and holds up when the losers ask how you chose.Video & AudioHow to Record Your Screen — No App to InstallRecord a screen demo, bug report, or tutorial straight from your browser, then trim it, turn it into a shareable GIF, or pull just the audio — with the files never leaving your device.ImageProfile and Cover Photo Sizes: The 2026 Dimensions Cheat SheetYour avatar looks fine on your screen and cropped-wrong on everyone else's. The pixel dimensions each platform actually wants, why they differ, and how to resize once and post everywhere.CalculatorsPercentage Points vs. Percent: The Difference That Costs MillionsA rate going "from 5% to 6%" rose one percentage point — but twenty percent. Mixing up the two is how headlines mislead and budgets break. Here is the difference, made permanent.CalculatorsMetric ↔ Imperial: The Everyday Conversion Cheat SheetThe conversions you actually reach for — cooking, travel, temperature, height and weight — with the quick mental tricks that get you close without a calculator.Date & TimeLeap-Year Birthdays: When Do You Actually Turn a Year Older?People born on February 29th only get a "real" birthday every four years. How leap days work, the odds of being a leapling, and how the law decides when you legally age up.TextJSON vs. CSV vs. XML: Which Data Format to Use WhenThree ways to store the same data, each good at something different. A plain-English guide to what sets JSON, CSV, and XML apart — and how to pick without overthinking it.Video & AudioHow to Turn a Video Into a GIF (That Doesn't Look Terrible)GIFs autoplay everywhere and need no player — but they can balloon to huge, grainy messes. How to make a clean, small GIF from a video clip, and when a GIF is the wrong choice.PDFHow to Split a PDF or Pull Out Just the Pages You NeedYou need page 3, or chapter two, or everything except the cover — not the whole 200-page file. How to split a PDF and extract exactly the pages you want, privately.GeneratorsHow to Share a Password Safely (Without Emailing It)Sending a password over email or chat leaves it sitting in two inboxes forever. Safer ways to hand someone a secret — from splitting the channel to encrypting it so only they can open it.GeneratorsHow to Make Custom Slack Emoji (That Actually Look Good)Custom emoji are the personality of a Slack workspace. How to make one that's crisp, correctly sized, and named so people can actually find it — plus the specs that stop uploads from being rejected.CalculatorsHow to Calculate a Discount (and Why "Stacked" Deals Lie)Work out any sale price in your head, see through "30% off then an extra 20%" (it's not 50%), and know whether the discount comes before or after tax. The shopping math that saves real money.Date & TimeHow to Count the Days Between Two Dates (Correctly)Counting days sounds trivial until leap years, inclusive-vs-exclusive counting, and "how many weeks until" trip you up. The rules that make date math come out right every time.Video & AudioHow to Extract Audio From a Video (MP4 to MP3)Pull just the sound out of a video — a lecture, an interview, a song from a clip — into a small MP3 you can play anywhere, without uploading the file to a stranger's server.ImageDPI vs. PPI: What Resolution Actually Means for Print and ScreenWhy "300 DPI" matters for a print but means nothing for Instagram, why the DPI you save a file at is invisible to your screen, and the one number that decides if an image looks sharp: pixel dimensions.HealthHow Many Calories to Lose a Pound (and Why the Simple Math Lies)The famous "3,500 calories = one pound" rule, why it overpromises for long-term weight loss, and how to set a deficit that actually works without wrecking your metabolism.HealthBMR vs. TDEE: How Many Calories You Actually Burn in a DayYour body burns calories just staying alive — then more for everything you do. What BMR and TDEE mean, how they're estimated, and why they're the number every diet plan quietly depends on.CalculatorsBaking by Weight: Why a Cup of Flour Isn't a Cup of FlourA cup of flour can weigh anywhere from 120 to 150 grams depending on how you scoop — which is why the same recipe comes out differently each time. How to bake by weight and get it right.ImageAspect Ratios Explained: 16:9, 4:3, 1:1 and Why Things Get CroppedWhy a photo that fits your screen gets its head cut off on Instagram, what 16:9 and 9:16 actually mean, and how to crop for the shape a platform wants instead of fighting it.TextASCII, Unicode, and UTF-8: What "Just Text" Really IsWhy an emoji counts as two characters, why a pasted document turns into "é" garbage, and what actually happens when you type. Character encoding, explained without the jargon.GeneratorsAre QR Codes Safe? How to Spot a Malicious OneA QR code is just a link in disguise — which is exactly why scammers love them. How "quishing" works, the red flags to check before you scan, and how to make codes people can trust.TextThe Regex Cheat Sheet: 8 Building Blocks That Cover 90% of Real WorkRegular expressions without the headache. The eight building blocks — character classes, anchors, quantifiers, groups — with copy-paste examples you can test live in your browser.HealthIs BMI Actually Accurate? What the Number Really Tells YouBMI was invented for populations, not people. Here is what your BMI does and does not measure, why athletes and different body types get misread, and better numbers to check alongside it.CalculatorsHow to Split the Bill Without the Awkward MathHow much to tip, whether to tip on the pre-tax amount, how to split a restaurant bill evenly or by item, and how tipping rules change once you leave the US.GeneratorsHow Strong Is Your Password, Really?What "crackable in 3 seconds" actually means, why length beats symbols, why passphrases win, and how to generate a genuinely strong password that never leaves your browser.PetHow Old Is Your Dog in Human Years? (Forget "Multiply by 7")The "one dog year equals seven human years" rule is a myth. Here is how dogs actually age — faster at first, then by breed size — and how to estimate your dog's real human-equivalent age.ImageWhat Is WebP? (And How to Convert To and From It)What the WebP image format is, why websites use it, where it still causes compatibility headaches, and how to convert WebP to JPG or PNG for free in your browser.ImagePNG vs JPG: Which Image Format Should You Use?A plain-English comparison of PNG and JPG — how they differ, when to use each, what happens to file size and quality, and how to convert between them for free.ImageHow to Reduce Image File Size (Without Wrecking the Quality)Practical ways to shrink an image for email, uploads, and faster web pages — resize the dimensions, pick the right format, and do it all in your browser with no upload.PDFHow to Merge PDF Files for Free (Without Uploading Them)Combine several PDFs into one file in the right order, entirely in your browser — no watermark, no sign-up, and nothing sent to a server.ImageHow to Make a Favicon (Convert a PNG to ICO)What a favicon is, what size and format it should be, and how to turn a PNG, JPG, or SVG logo into a multi-size .ico file for free in your browser.TextHow to Format and Validate JSON (and Fix Common Errors)Beautify messy JSON, find the exact line of a syntax error, explore big payloads as a collapsible tree, and copy any value — all in your browser.GeneratorsHow to Create a QR Code for Free (No App, No Sign-Up)What QR codes can do, how to make one for a link, text, or Wi-Fi in seconds, and how to keep it scannable when you print or resize it — all in your browser.PDFHow to Convert a PDF to JPG (Free, No Upload)Turn PDF pages into JPG images right in your browser — every page at once, no watermark, no sign-up, and nothing uploaded to a server.PDFHow to Convert JPG to PDF (Free, in Your Browser)Turn one photo or a whole stack of images into a single PDF — great for scans, receipts, and documents — with no upload, no watermark, and no sign-up.ImageHow to Convert HEIC to JPG (and Why iPhone Photos Are HEIC)Why your iPhone saves photos as HEIC, how to convert them to JPG for free without uploading, and how to stop it happening in the first place.TextBase64 Encoding Explained (and How to Encode or Decode It)What Base64 is, why it is used for data URLs, email, and tokens, why it is not encryption, and how to encode or decode text and files for free in your browser.