Taxonomy navigator — navigate the NCBI taxonomy tree top-down to filter sequences by taxonomic origin.

Select a Kingdom from the first box (e.g. SAR, Opisthokonta, Archaeplastida, etc). The next box will load the corresponding Phyla. Further sub-ranks (class, order, family…) cascade as you narrow down your selection.

Once a taxon is selected, the Species list below is populated with all species in that group that have sequences in the database.
Hold Shift + click to select a range of species. Hold Ctrl + click to add or remove individual species.
If no species is selected, the search returns sequences from all species in the selected taxon.

Selection can be cleared by pressing the "x Clear" button that appears on the right side of the names list, or you can navigate back to the previous level with the arrow on the left

Leave all boxes empty to search across all kingdoms.

Taxonomy filters (Taxonomy, shortname and scientific name) are mutually exclusive. Filling one will reset the others.