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.