Guides
16 editorial guides written by Guga in Tbilisi, the shortest 869 words, with examples, code, and FAQs. They show how our tools are actually used, which formats to choose, and how to stay private with everything running locally.
Last updated 2026-10-15 · 16 articles · CollectionPage
Feet and Inches to Centimeters: Height Explained
A height like 5′10″ is a pair of numbers, not a decimal: five feet plus ten inches, with the feet converting at 30.48 centimeters and the inches at 2.54. The arithmetic, the four mistakes that corrupt height records, and the settings where precision actually matters are below; to convert one height in either direction, the height converter linked from this guide gives the exact pair instantly.
Favicon Sizes: What Your Website Actually Needs
A favicon is one small square of artwork that a browser requests at particular sizes, so a site needs a few purpose-built renditions rather than a single export scaled into every slot. Which pixels each context asks for, why a multi-size .ico still earns its place, and how the pieces are declared is below; to build the whole set from one image, the favicon generator linked from this guide produces the files and the tags.
ASCII Art: How Text Pictures Are Made
ASCII art is a picture assembled from ordinary printable characters, with each glyph's weight standing in for a pixel's brightness. The style grew out of typewriters and bulletin boards and never left, because plain text renders everywhere. How the mapping works and which controls shape it is below; to draw a banner from a word rather than an image, the ASCII Text Generator on this site renders it in a classic font.
Do Image Converters Upload Your Photos?
A converter that runs inside the page decodes your file into memory and re-encodes it there, so nothing is sent anywhere and you can check that claim yourself in the Network tab. That is a different promise from a server-side tool, where the photo lands on hardware you do not control. What each format costs, and how to verify it, is below; to convert a file now, the PNG to JPG converter linked from this guide works in the browser.
PX vs REM vs EM: Which Unit Belongs Where
px ignores the font size a reader has set, rem follows the root element, and em follows the parent, so nesting em compounds while rem never surprises you. That single difference is the whole accessibility case for font-size guidance, and it is what decides where each unit belongs in a layout. The rule of thumb, the arithmetic and the traps are below; to convert one specific value, the PX to REM converter linked from this guide does it instantly.
How to Choose QR Code Error Correction Level (L, M, Q, H)
L gives capacity, H gives resilience. Learn which level survives logos, dirt, and low light without making the code unruly.
Password Security in 2026: What NIST Actually Recommends
NIST now says long, random, checked against breaches beats C0mpl3x! rules. Build a 2026-proof password strategy that humans can actually follow.
12 JSON Syntax Errors and Why Parsers Reject Them
JSON is strict on purpose: it is a wire format between systems that share no runtime, so every ambiguity has to be settled by whoever wrote the file. That turns an ordinary slip — a trailing comma, a single-quoted name, a comment — into a hard parser failure, and one slip, a repeated key, into silent corruption. All twelve are shown broken and then fixed below; to check a file of your own, the JSON Formatter linked from this guide parses it locally.
BMI: What Body Mass Index Misses and What to Use Instead
BMI tells weight per height squared, not health. Discover its blind spots for athletes, seniors, and different ethnicities, and better metrics to pair it with.
Loan Calculator Formula: Amortization and APR
Monthly payment is not just rate times principal. Unpack the amortization formula, see why early payments are interest-heavy, and compare APR.
What Is Base64 Encoding? The 33% Overhead Explained
Base64 writes any byte as one of 64 safe ASCII characters, which makes binary survivable in text-only channels and costs about 33% more space. It is an encoding, not encryption, and nobody needs a key to undo it. What the alphabet and the padding rules actually specify is below; if you just need a string turned into Base64, the Base64 Encoder / Decoder tool linked from this guide runs in your browser.
PDF Merge vs Split: When to Use Each
Merge combines, split extracts. Learn when each saves time, how to reorder safely without upload, and how to keep sensitive PDFs local.
Lorem Ipsum History and Modern Use
Lipsum looks like Latin but is corrupted Cicero. Learn its history, why it helps focus on layout, and when real content should replace it.
URL Encoding: %20, %2F, Plus Signs & RFC 3986
Two escaping systems, one job each. Percent-encoding makes a value safe to travel inside a URL: %2F is an escaped slash, %3F an escaped question mark, %20 an escaped space. HTML entities solve a different problem entirely, making text safe inside markup rather than inside an address. Which one you need, what RFC 3986 actually requires, and the three mistakes that break most links are below; to convert a real string instead, the free URL Encoder / Decoder applies exactly those rules locally.
Randomness Explained: Crypto.getRandomValues vs Math.random
Math.random is fast but predictable. GetRandomValues is cryptographic. Understand entropy, seeding, modulo bias, and when each belongs in your code.
FIGlet Banners: Why ASCII Art Breaks on Paste
ASCII art is stored character by character rather than drawn by an algorithm, which is why it needs a monospace font at both ends and collapses the moment you paste it into a chat client. The fonts, the joining rules and the paste traps are below; to draw one right now, the ASCII Text Generator linked from this guide turns words into a banner instantly.