Developer Tools

Several of these overlap in what they accept and differ in what they are for. A few notes on choosing between them, and on two places where the wrong choice has consequences beyond an inconvenient result.

Validate before you format

The JSON utilities form a sequence rather than alternatives. A validator tells you whether a document parses and points at the line where it stops, which is what you want when something is broken. A formatter assumes the input is already valid and makes it readable. A minifier strips insignificant whitespace for transport. Running a formatter on a broken document usually produces an unhelpful error, so reach for the validator first when the input came from somewhere you don't control.

Identifiers aren't passwords

A UUID and a secret key look similar and are built for opposite purposes. A version 4 UUID is random and effectively collision-free, which makes it excellent as an identifier, but identifiers are meant to be shareable and often appear in URLs and logs. Using one as a security token means treating a value designed to be visible as though it were confidential.

A secret key needs to come from a cryptographically secure source and needs to stay out of logs, URLs and version control. If a value protects something, generate it as a key, not as an identifier, and store it accordingly.

Slugs and the characters that break them

A slug generator does more than replace spaces with hyphens. It has to decide what happens to accented characters, non-Latin scripts, ampersands and emoji, and the choice is visible to users for as long as the URL exists. Transliterating an accented character to its closest ASCII equivalent keeps URLs readable and typeable, while stripping it entirely can silently merge two distinct titles into the same slug.

Worth remembering that slugs are effectively permanent. Changing one later breaks every existing link and any accumulated ranking, so it's cheaper to think about the rules once at the start than to migrate URLs afterwards.