Guides & Tutorials
15 guides to help you get the most out of free online tools — how-to walkthroughs, deep explanations, comparisons and problem-solving tips.
How to Encode and Decode Base64: A Complete Guide
Learn what Base64 encoding is, how it works, when to use it, and how to encode and decode Base64 in your browser — no tools or signup needed.
explanationColor Formats Explained: HEX, RGB, and HSL
Understand the three most common web color formats — HEX, RGB, and HSL — how each represents color, when to use which, and how to convert between them.
referenceDNS Records Explained: A, AAAA, MX, TXT, CNAME, NS
A complete reference guide to DNS record types — A, AAAA, MX, TXT, CNAME, and NS — with examples, use cases, and how to look them up.
explanationHashing Algorithms Explained: MD5, SHA-1, SHA-256, SHA-512
Understand how cryptographic hash functions work, the differences between MD5, SHA-1, SHA-256, and SHA-512, and which to use for integrity checks vs password storage.
explanationJSON Formatting Best Practices: Readable, Valid, and Efficient
Understand the conventions for formatting JSON: indentation, key ordering, minification, trailing commas, and when to pretty-print vs minify.
explanationUnderstanding JSON: A Beginner's Guide to Formatting and Validation
Learn what JSON is, its syntax rules, common data types, and how to format and validate JSON data using free online tools.
how-toHow to Decode a JWT and Inspect Its Claims Safely
Learn the three-part structure of a JSON Web Token, how to decode the header and payload without verifying, and why decoding is not the same as trusting.
comparisonMarkdown vs HTML: Which Should You Use for Content?
Compare Markdown and HTML across readability, expressiveness, learning curve, use cases, and rendering — and learn when to pick each (or both).
problem-solvingPassword Security: How to Generate, Store, and Audit Strong Passwords
Solve the most common password security problems: generating strong passwords, hashing them correctly, avoiding reuse, and auditing existing credentials.
referenceRegular Expressions Cheat Sheet: Syntax, Flags, and Common Patterns
A complete reference for regular expression syntax: metacharacters, character classes, quantifiers, anchors, groups, flags, and ready-to-use patterns for emails, URLs, dates, and more.
how-toHow to Convert Unix Timestamps to Human-Readable Dates
Learn what a Unix timestamp is, how to convert it to a human-readable date and back, and how to handle time zones correctly when working with epoch time.
referenceUnit Conversion Reference: Length, Mass, Temperature, and Area
A complete reference of conversion factors for length, mass/weight, temperature, and area, with exact formulas and worked examples for each.
how-toHow to Encode and Decode URLs: A Complete Guide
Learn what URL encoding (percent-encoding) is, why it is required, and how to encode and decode URLs in your browser — no signup, fully private.
comparisonUUID v1 vs v4 vs v5: Which Version Should You Use?
Compare UUID versions 1, 4, and 5: how each is generated, their trade-offs in uniqueness, ordering, and determinism, and which to pick for your use case.
how-toHow to Count Words, Characters, and Reading Time Accurately
Learn how word and character counts are defined across languages, how to estimate reading time, and how to use a counter to hit limits for essays, tweets, and meta descriptions.