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How Subnetting Works: CIDR, Masks, Host Ranges
An IPv4 subnet calculator takes an address and a CIDR prefix, such as 192.168.1.10/24, and derives the network address, broadcast address, first and last usable host, subnet mask, wildcard mask, and total and usable address counts.
Luhn Algorithm: How Credit Card Validation Works
A credit card validator confirms that a number is structurally correct, not that it belongs to a real account.
How to Find and Replace Text Without Regex
This tool does literal find and replace over a block of pasted text.
Why Is My JSON Invalid? Common Errors and Fixes
A JSON validator checks text against the grammar in RFC 8259 and, when the text is broken, tells you the exact line, column, and character of the first error, phrased in terms of what it expected.
Do Spaces Count as Characters? Limits and Bytes
A character counter counts the characters in your text with and without spaces, plus words, sentences, paragraphs, lines, reading time and byte size, updating live as you type.
CSS Animation vs Transition: Keyframes Explained
A CSS animation moves an element through a @keyframes sequence over time, and unlike a transition it needs no trigger and can loop.
How CSS Transitions Work: Shorthand and Timing
A CSS transition animates the change between two values of a property over a set duration. It belongs on the base state, not the hover state, so the element eases in both directions.
How CSS Transforms Work: Order, Origin and 3D
The CSS transform property repositions and reshapes an element without affecting page layout, which is what makes it the right tool for hover effects and animation.
How Chmod Permissions Work: 755, 644 and Octal
Unix permissions cover three classes (owner, group, others) with three bits each (read=4, write=2, execute=1).