Head height is what actually gets photos rejected
Every one of the five authorities specifies how tall your head must be within the frame, and it is a narrower range than people expect. India asks for the tightest crop of the lot — 80 to 85% of the frame — so a photo framed to US or UK proportions is refused there. Get the overall dimensions right and the head height wrong and the photo is still refused.
So the crown and chin lines are the main controls on this page, not an afterthought. Drag them onto the top of the head and the bottom of the chin, and the tool reports the resulting head height in millimetres against the range your authority publishes.
The United States is the only one of the five that also publishes an eye position — the eyes must sit a specified distance up from the bottom edge. Where a country publishes it, this tool uses it; where it does not, the head is placed by a stated composition convention rather than a made-up rule.
Digital and printed are different submissions
An online renewal wants a digital file at a pixel size, within a file-size range, in an accepted format. A paper application wants a physical print at a physical size on photo paper. The requirements are not the same and neither is the file you need.
The UK publishes a pixel minimum for its online service; Canada and Australia expect prints from a photographer. Where a country accepts both, this tool offers both, and it says which one you are producing.
For a print, the sheet is laid out at true physical size with the resolution written into the file, so "print at 100%, no scaling" means something at the shop counter. A photo printed at the wrong scale is the second most common reason for a rejection after head height.
What software cannot judge
A calculator can measure a head and count pixels. It cannot tell whether your expression is neutral, whether your glasses are catching a reflection, whether there is a shadow on the wall behind you, or whether the photograph still looks like you.
So those are presented as a checklist rather than as green ticks. Every item on it is a real published reason for refusal, and every one of them is something you have to look at yourself.
The most commonly missed: glasses are not accepted at all for a US passport; a shadow on the background counts as a non-plain background; and most authorities require the photo to have been taken within the last six months.
Why this one runs locally, specifically
A passport photo is a picture of your face, cropped to a specification that identifies which country's document you are applying for, uploaded alongside the date you applied. That is a lot to hand to a free website with an advertising business model.
Everything here happens in your browser. There is no upload, no queue, no temporary file on somebody's server that gets cleaned up "within 24 hours", and no third-party request of any kind — which you can verify rather than take on trust.
If your photo needs a plain background, the keying tool is built into this page and works the same way: locally, on your device, on a photo that has not gone anywhere.