Drop your photo, get a JPEG that meets the GOV.UK digital photo file rules — at least 50 KB, at most 10 MB — without cropping it (HM Passport Office crops for you). Nothing is uploaded; it all runs in your browser.
The online passport application accepts a digital photo that is at least 600 pixels wide and 750 pixels tall, at least 50 KB and no more than 10 MB, clear and in focus, in colour, and unaltered by computer software. It must have been taken in the last month, and you need a fresh one for every application — even a renewal where you look the same. This page is preset to the 50 KB–10 MB window with no pixel size set, which is deliberate: GOV.UK says do not crop your photo — HM Passport Office crops it for you. Leave the Exact size field empty and submit the full head-shoulders-upper-body frame.
That rule is about your appearance: no retouching, no filters, no AI cleanup, no editing out shadows. It doesn't prohibit the file plumbing every photo goes through — a booth's kiosk software also encodes, resizes and compresses. PixFit changes bytes, not looks: it re-encodes at the best quality that fits the size window and touches nothing else. Don't run your photo through anything that “enhances” it — that's the alteration HMPO rejects.
Photos land under 50 KB for one usual reason: they were sent through WhatsApp or a messaging app that recompressed them. PixFit can pad a JPEG up to the 50 KB floor with a spec-valid comment segment, but padding adds no detail — and HMPO also checks that the photo is at least 600×750 pixels, clear and in focus. If your only copy is a small, soft, message-app version, the honest fix is the original file (ask the sender for “actual size”/document mode) or a new photo. Likewise PixFit won't upscale here: a photo smaller than 600×750 needs retaking, not resampling.
A high-resolution scan or a large phone photo over 10 MB drops straight in and comes out at best quality under the cap, full resolution kept. An iPhone HEIC can also be dropped directly — PixFit decodes it in your browser and outputs a JPEG, the safe universal format for uploads (GOV.UK doesn't publish a format list, so stick to JPEG). The re-encode also strips EXIF metadata, including the GPS position of wherever the photo was taken.
Everything that actually gets photos rejected: plain light-coloured background, facing forwards, plain expression, mouth closed, eyes open and visible, no hair across the eyes, no head covering (except religious or medical), no shadows on your face or behind you, no glasses unless you must wear them — and someone else holding the camera, since it can't be a selfie. Babies and children have their own rules. Read the current list at gov.uk/photos-for-passports before you submit — and note a booth or shop photo code is the route HMPO says is most likely to be approved first time. Printed photos for paper applications are a different spec (35×45 mm) that PixFit doesn't handle.