The Short Answer
INDEX-MATCH is more flexible and faster on large datasets, but VLOOKUP is simpler for basic left-to-right lookups. In Excel 365 and Google Sheets, XLOOKUP now supersedes both for most use cases.
When VLOOKUP Still Wins
If your lookup column is already the leftmost column and you just need a quick reference, VLOOKUP is faster to type: =VLOOKUP(A2,Sheet2!A:D,4,FALSE)
When INDEX-MATCH Wins
INDEX-MATCH handles left lookups, doesn't break when you insert columns, and processes faster on 100K+ row datasets: =INDEX(Sheet2!D:D,MATCH(A2,Sheet2!A:A,0))
The Modern Alternative: XLOOKUP
In Excel 365 and Google Sheets, XLOOKUP combines the best of both: =XLOOKUP(A2,Sheet2!A:A,Sheet2!D:D,"Not found")
Converting Between Platforms
Both formulas work identically in Excel and Google Sheets for basic usage. The key difference: Google Sheets supports ARRAYFORMULA wrapping for batch operations, while Excel uses dynamic arrays natively.