# Using Fasta Input

If you would like to run augur on viral data, or bacterial SNP data, you probably would like to start with Fasta sequence data.

### Sequence data

Your sequence data should

* consist of homologous sequences that can be aligned unambiguously
* needs to contain sufficient diversity to allow reliable tree reconstruction
* should be of similar length. Mixing short sequences (300bp) with much longer ones (10000bp) often yields unexpected results.