Accounts
Splitwise's help center says it thinks “everyone in a Splitwise group can log in and see their balance.” You can add someone by name only as a placeholder member, “tracked by name, without contact info”, and give them access later with an email or phone number.
In GroupTab, nobody makes an account. You send one link, everyone taps their name, and their phone remembers them. A 4-digit PIN can lock a name so nobody else picks it.
Limits on the free plan
Splitwise's help center says “free users can add up to 4 expenses each day”, and its Pro page offers “No limits and no ads.”
GroupTab is free, with no daily limit on expenses and no ads. Tabs are erased 90 days after the last change, because they're meant for a trip, not a ledger you keep for years.
Paying each other
GroupTab never holds or sends money. Instead, everyone adds their Venmo or Cash App once, and paying someone is one tap with the amount filled in (for US dollars). The person paid confirms it arrived, so both sides agree.
When Splitwise is the better choice
If you share costs with the same people every month, like roommates, or you want receipt scanning, currency conversion and charts, Splitwise's long-running ledger and Pro features fit better. GroupTab is for the trip, the bachelorette or the away game: start it in seconds, settle it, done.