Guides & Tutorials
Clear, practical explanations of the formats, techniques, and everyday tasks behind RunWebTools. No jargon, no fluff — just what you need to know, with the right tool one click away. Browse by topic below.
What Is JSON? A Plain-English Guide (and How to Fix Common Errors)
Understand what JSON is, how its syntax works, and how to quickly fix the most common JSON errors — trailing commas, single quotes, unquoted keys, and more.
Base64 Encoding Explained: What It Is and When to Use It
What Base64 actually does, why it makes data ~33% larger, common uses like data URIs and email attachments, and the security myths worth knowing.
Character Encoding: Unicode and UTF-8 Explained
Why text sometimes turns into garbled symbols, what Unicode and UTF-8 actually are, the difference between characters, code points, and bytes, and how to fix mojibake.
YAML Explained — and How It Compares to JSON
What YAML is, why it's popular for config files, how its indentation-based syntax works, the gotchas to watch for, and when to choose YAML over JSON.
What Is XML? Tags, Attributes, and How It Works
A plain-English introduction to XML — elements, attributes, nesting, and well-formedness — plus how it differs from HTML and where it's still used today.
The CSV Format Explained (and How to Fix Common Problems)
How CSV files really work, why commas and quotes cause trouble, the encoding and delimiter pitfalls that break spreadsheets, and how to avoid them.
URL Encoding Explained: Percent-Encoding and When You Need It
What URL encoding (percent-encoding) is, why spaces become %20 and other characters get escaped, reserved vs. unreserved characters, and when to use it.
Naming Case Styles: camelCase, snake_case, kebab-case & More
A clear guide to the common naming conventions in code — camelCase, PascalCase, snake_case, kebab-case, and CONSTANT_CASE — and where each one is used.
Word Count and Readability: What the Numbers Mean
How word, character, and sentence counts are measured, what reading-time estimates are based on, and how readability affects whether people finish what you write.
What Is a URL Slug? How to Make Clean, Readable URLs
What a slug is, why clean URLs matter for SEO and sharing, the rules for turning a title into a slug, and how to handle accents, spaces, and special characters.
How to Clean Up and Deduplicate Text
Practical techniques for tidying messy text — removing duplicate and empty lines, sorting, trimming whitespace, and stripping the invisible characters that sneak in when you copy and paste.
How to Compress Images for the Web Without Losing Quality
A practical guide to shrinking image file sizes for faster websites — lossy vs lossless, choosing between JPEG, PNG, and WebP, and how much quality you can safely trade.
Image Formats Explained: PNG, JPG, GIF, WebP, and SVG
A clear comparison of the common image formats — which to use for photos, logos, transparency, and animation, and why WebP and SVG are often the smartest choice.
How to Resize and Crop Images for the Web
The difference between resizing and cropping, why serving oversized images slows pages down, how to keep aspect ratio, and how to size images for the space they fill.
EXIF Metadata and Photo Privacy: What Your Photos Reveal
What EXIF metadata is, how photos can carry your GPS location, camera, and timestamps, why that's a privacy risk when sharing, and how to strip it out.
How to Merge, Split, and Organize PDF Files
A practical guide to combining, splitting, reordering, rotating, and extracting pages from PDF files — safely in your browser, with no uploads.
How to Reduce PDF File Size (Without Wrecking Quality)
Why PDFs get so large, what actually drives their size, how compression re-encodes images, and practical ways to shrink a PDF to fit an email or upload limit.
How to Convert PDFs to Images or Text
When to turn PDF pages into images versus extracting their text, why some PDFs have no selectable text, and how to convert either way in your browser.
JWT Explained: Structure, Claims, and How to Decode One
What a JSON Web Token is, the three parts every JWT has, what the common claims mean, how signatures work, and the security pitfalls to avoid.
Working with Unix Timestamps: Epoch Time Made Simple
What a Unix timestamp is, why computers count seconds from 1970, seconds vs. milliseconds, time zones and UTC, and the Year 2038 problem — explained clearly.
Color Formats Explained: HEX, RGB, and HSL
How web colors work — what HEX, RGB, and HSL actually mean, how to convert between them, when to use each, and how alpha transparency fits in.
What HTTP Status Codes Mean (200, 301, 404, 500 and More)
How to read HTTP status codes at a glance, what the five classes mean, and a tour of the codes you'll actually run into — from 200 and 301 to 404 and 500.
Regular Expressions for Beginners: A Gentle Introduction
Learn regex from scratch — what patterns are, the core building blocks (character classes, quantifiers, anchors, groups), and how to read and write your first expressions.
How to Create and Manage Strong Passwords
What actually makes a password strong, why length beats complexity, how attackers really crack passwords, and practical habits like password managers and 2FA.
Two-Factor Authentication (2FA) Explained
What two-factor authentication is, why a password alone isn't enough, how authenticator apps and hardware keys work, and which method to choose.
How to Test a Used Phone Before Buying: A 10-Minute Checklist
A practical checklist for inspecting a second-hand phone on the spot — dead pixels, touch dead zones, sensors, battery health, cameras, and speakers — using free browser tests.
Why Your Mouse Double-Clicks on Its Own (and How to Fix It)
What switch chattering is, why worn mice register phantom double-clicks and keyboards double-type letters, how to confirm it with a browser test, and your repair options.
Monitor Refresh Rate Explained: 60Hz vs 120Hz vs 144Hz
What refresh rate actually is, whether you can see the difference past 60Hz, why a new 144Hz monitor often runs at 60 by mistake, and how to verify yours is set correctly.
How to Test Your Mic, Camera, and Speakers Before a Video Call
A two-minute pre-call routine — check that your microphone picks up sound, your webcam looks right, your speakers play both channels, and your connection is stable.