Classic Disney (1951): This animated version is generally considered appropriate for all ages. It's lighthearted, whimsical, and features classic Disney charm.
Tim Burton (2010): This live-action adaptation is more suited for older children and adults. It has darker themes, more intense imagery, and some scary moments. It's not necessarily "scary" but the visuals can be a bit overwhelming for younger viewers.
Other adaptations: There are several other "Alice in Wonderland" films out there, including more recent ones like "Alice Through the Looking Glass." Each one will have its own rating and suitability for different age groups.
To be sure, it's always best to check the movie's official rating (like PG or PG-13) and read reviews to get a better sense of its content.