Female House Finch lacks the distinctive face pattern of the female Cassin's Finch. Purple Finch is very similar in all plumages but has unstreaked undertail coverts and a smaller bill. Male Cassin's has a brighter red crown. Female Cassin's has finer streaking on the breast and a less noticeable face pattern. Pine Siskin is similar to female but smaller and lacks face pattern.
Sparrows are slimmer with longer tails and different markings.