Passport, PAN, Aadhaar, exam forms and signatures each demand a different size, a different orientation and a different file weight, and getting any one of them wrong means the form comes back. Pick the document you are filing for. Everything runs in your browser and no file is uploaded. Start from Image Tools if you need something more general.
Start from the form you are filling in, not from the pixel size you were given. The size follows from the document, and half the sizes circulating online belong to a different one.
Aadhaar is 35 x 45 mm portrait. A passport photo is also 35 x 45 mm, but the Passport Seva upload is specified in pixels as 630 x 810. PAN is 25 x 35 mm portrait, which is smaller than both. A PAN signature is 45 x 20 mm landscape. These are four different requirements that look interchangeable in a list and are not, which is why several sites publish 531 x 413 as a PAN photo size when that number is simply the Aadhaar figure written backwards. Pick the tool by document and the size comes with it.
Passport, PAN and Aadhaar. Each has its own frame, its own KB window and its own portal.
A photograph is portrait, carries detail and almost always lands above its file size ceiling, so quality has to come down. A signature is landscape, is mostly white paper with a few thousand dark pixels, and compresses so far that it lands below its minimum instead. Those need opposite fixes. If your problem is a photo, start with passport photo, PAN card photo or Aadhaar photo. If it is a signature that keeps failing a size check, go to signature resize. If your exam portal wants both in one sitting, exam form photo carries the presets side by side.
Specs that change with every notification cycle, so every preset links the source you should confirm against.
Not every form is a government form. When you have been handed a pixel size with no document attached, image resizer is simpler and faster. For a weight limit only, use resize image to KB. If the dimensions are already right and the file is just heavy, compress to 50KB holds the pixels and lowers quality instead. To set 200 or 300 DPI on a file you already have, use DPI changer, and to settle a shape before cropping anything the aspect ratio calculator never opens a file at all. Those all live under image resize and DPI tools.
Every tool in this category follows the same shape, so learning one means you already know the rest.
Anyone who has been handed a pixel size, a KB limit and a DPI number on the same page and told to get all three right.
A document photo is judged on dimensions, file weight, background and framing, and each is checked on its own. Getting three right and one wrong produces the same rejection as getting everything wrong, usually with no explanation of which rule you broke. The file weight rule is the one people miss most, because it has a floor as well as a ceiling: a photo compressed too hard is refused just as firmly as one that is too heavy. Start with passport photo or PAN card photo and the size rule is applied for you in both directions.
India moved passport photographs to the ICAO 35x45mm standard, and the older 2x2 inch square is now a leading cause of rejection. Passport and OCI requirements have since diverged, and published OCI guidance contradicts itself. NSDL and UTIITSL process the same PAN application to different photo specifications. UPSC and SSC now capture some photographs live by webcam rather than by upload. Every tool here links the official portal for its document and asks you to confirm before uploading, because a specification that changed once will change again. Check exam form photo against the current notification PDF, and Aadhaar photo against UIDAI directly.
Five document tools, locked crop shapes and an honest checklist of what was verified. Free, no sign-up, and nothing leaves your device.
Start with Passport Photo