01 The short version
OmniDiskSweeper shows your files in a column list, sorted largest
to smallest, and lets you delete them. That's the whole app, and
that focus is a feature: it's free, tiny, from a vendor people
have trusted for two decades, and it runs on Intel Macs and older
macOS.
Delve shows the same underlying data as a squarified treemap, so
the biggest things are obvious without reading a single number.
It also breaks out on-disk versus logical size with APFS clones
counted once, and routes deletes through the Trash so they're
undoable. The trade: it needs macOS 26 and Apple Silicon.
03 Where OmniDiskSweeper wins
Simplicity, and the trust that comes with it. It does one thing,
it's been doing it reliably for a very long time, and The Omni
Group is about as dependable as Mac developers get. It's tiny, it
opens instantly, and it runs on Intel Macs and older macOS that
Delve won't touch. If you just want the ten biggest files so you
can nuke them and move on, the plain list is arguably the faster
path.
04 Where Delve wins
A list tells you the order; a treemap tells you the shape. When
the problem is a thousand medium files in one folder rather than
one giant file, the map makes that obvious and the list buries
it. Delve also counts APFS clones and hardlinks once, so the
space it promises is the space you'll get back, and every delete
goes through the Trash so a mistake is one Undo away rather than
gone. Plus the Mac plumbing: Spotlight, Shortcuts, Quick Look.
The accounting details
are in the build notes.
Our honest recommendation
On an Intel Mac or older macOS, or when you want the
smallest, simplest possible tool: OmniDiskSweeper is a fine,
honest choice.
On Apple Silicon with macOS 26, if you'd rather see the shape
of your disk than read a list of it, with honest on-disk
numbers and undoable deletes: Delve. Both are free.