No sign-up, no usage cap, no paid tier — unlike every other AI Excel tool. What makes it different: • Tell it your Excel version (2016–365) and it won't suggest functions you can't run • Comma or semicolon separator — European Excel gets working formulas, not syntax errors • Regex built for RE2, the engine Excel and Sheets actually use • 336 function pages, each with syntax, 3 worked examples and its real error modes • Every answer names what will break it, not just the formula