The four groups
Built-in React hooks
USESTATE · USEEFFECT · USEMEMO · USEREF
CSS length units
PX · REM · VH · CH
Browser DevTools panels
ELEMENTS · NETWORK · CONSOLE · SOURCES
Words paired with FRAME
STACK · KEY · MAIN · WIRE
Why this puzzle works
Friendly puzzle, mostly to teach the format. MAIN is the only mildly-tricky tile: it could feel like a 'default git branch' or a 'main thread' but here it's wordplay (mainframe). The wordplay clue: every purple tile must compound cleanly with FRAME — stackframe, keyframe, mainframe, wireframe. If a tile gives you only one valid compound, it's purple.
How to read a Connectle without solving it
A code-themed grouping puzzle rewards counting as much as recognition. Start by listing every plausible group, then notice which tiles appear in two lists. Whichever group has exactly four unambiguous members is your anchor — solve it first and the rest of the board collapses by elimination. The hardest tier (purple) is almost always wordplay: tiles that share a prefix or suffix, not a concept. If a tile feels orphaned, ask whether the same word could follow or precede a common engineering word like root, stack, cache, or queue.