Both modes use identical rules — 6 guesses, green/yellow/gray feedback — but adding one letter changes the puzzle more than you'd expect.
Every extra letter position multiplies the number of valid words that could fit. That means a green tile in 6-letter mode narrows things down less, proportionally, than a green tile in 5-letter mode, because there are simply more remaining words that could still match your other unknowns.
In 5-letter mode, openers like CRANE or SLATE work because they pack five distinct common letters into a tight space. In 6-letter mode, words like GARDEN, MASTER, or PLANET do the same job across six positions, often naturally including a common suffix pattern (like -ER or -ET) that shows up often in longer words. See Best Starting Words for more on picking openers by mode.
Longer words are statistically more likely to contain a repeated letter (double consonants like -TT-, -SS-, -LL- are common in 6-letter English words). If you're not used to reasoning about repeated letters, this catches a lot of players off guard in 6-letter mode. Brush up with How to Handle Repeated Letters before switching over.
It's worth repeating: nothing about how tiles are colored changes between modes. If you understand the color rules in one mode (see How to Play Wordle), you already understand them in the other. What changes is how much work each guess has to do, which is why the strategy guidance in Wordle Tips & Strategies matters more, not less, in 6-letter mode.
Switch modes any time with one click — no reload needed.