What size is a United States passport photo?

51 × 51 mm (2.01 × 2.01 in). A digital file is 600 × 600 px.

Can I take a United States passport photo with my phone?

Yes. PhotoSpec crops to 51 × 51 mm and checks the framing before you save. Photos are processed on the phone and are not uploaded.

United States

51 × 51 mm · Plain white or off-white · 600 × 600 px · Up to 10 MB · Taken within the last 6 months

Photo size	51 × 51 mm (2.01 × 2.01 in)
Head height	50–69% of the photo height
Eye line	about 38% down from the top edge
Background	Plain white or off-white
Digital size	600 × 600 px, up to 10 MB
File format	jpeg/png/heic
How recent	Taken within the last 6 months
Retouching	Not allowed. The photo must not be digitally altered beyond cropping.
Background replacement	Not allowed. Shoot against a wall of the required colour.
Where to take it	You can take this photo yourself.

Source: travel.state.gov passports/photos. Rules change — check the issuing authority before you submit.

Online application: upload a digital photo.
For online renewal, upload a digital photo travel.state.gov
The photo can be taken at the application office.
An acceptance facility that will take a photo when you apply travel.state.gov

The authority allows a photo taken without a studio — its own wording is below.
A friend or family member travel.state.gov

Colour photo.
Submit 1 color photo taken in the last 6 months travel.state.gov
No filters, retouching or digital changes.
Submit the original, unedited photo without filters or digital changes travel.state.gov
Digital manipulation and/or retouching of the facial image on photographs is not acceptable fam.state.gov

At 10240 KB the upload limit is the most generous of the 2 United States documents we cover — a file prepared for one of the others will fit.
The authority sets a maximum file size but does not publish a pixel size, so the dimensions are your decision. Compress from a full-resolution photo rather than shrinking the picture until it fits.
HEIC is accepted, so a photo taken straight on an iPhone does not have to be converted before you upload it.

Checked against the issuing authority’s own published material. Requirements change without notice — confirm before you submit.

What size is a United States passport photo?: 51 × 51 mm (2.01 × 2.01 in). A digital file is 600 × 600 px.
Can I take a United States passport photo with my phone?: Yes. PhotoSpec crops to 51 × 51 mm and checks the framing before you save. Photos are processed on the phone and are not uploaded.

Visa — digital file 600×600 px, 10 MB here, 600–1200×600–1200 px, 240 KB there
Residence permit — same published size, background, digital file and capture rules as this document
Work permit — same published size, background, digital file and capture rules as this document
Citizenship — same published size, background, digital file and capture rules as this document

Processed on your phone. Photos are not uploaded.