What size do online forms usually ask for?
Common ranges; the portal's own instructions always win
| Upload | Typical file size | If no pixel size is given | Format |
|---|---|---|---|
| Passport-style photo | 20–50 KB (some allow up to 100–200 KB) | 300–600 px wide | JPG |
| Signature | 10–20 KB (some allow up to 100 KB) | 300–500 px wide, about 2–3 times wider than tall | JPG |
Real requirements, as of October 2026 (check the current notice before you apply):
- US visa photo (online visa forms such as the DS-160): JPEG, square, 600 × 600 to 1,200 × 1,200 px, at most 240 KB, with a compression ratio of 20:1 or less.
- US passport online renewal: a photo file (JPEG works) between 54 KB and 10 MB. A 600 × 600 color photo compressed exactly 20:1 weighs 54 KB, so a much smaller file is likely over-compressed.
- SSC (India): signature as a JPEG of 10–20 KB, about 4.0 × 2.0 cm. For recent One-Time Registration, the photo is captured live with a webcam instead of being uploaded.
- UPSC (India), 2026 cycle: photo JPG of 20–200 KB and signature JPG of 20–100 KB, plus a live photo captured during the application.
How do I photograph or scan a signature?
- Sign on plain white paper with the pen color the portal asks for; many require black ink.
- Photograph it in daylight or under a bright lamp, phone held parallel to the paper, with no shadow across the signature. A scanner works too.
- Crop tight around the signature with a small margin, using your phone's photo editor. The result should be about 2–3 times wider than tall.
- Optionally turn it black and white (a mono filter, or saturation down to zero) and raise the contrast so the paper reads as pure white. A clean white background compresses far better than gray paper.
- Compress it to the portal's range, as below.
How do I get the photo under 50 KB and the signature under 20 KB?
- For the photo, open Image to 50 KB and type 45 as the target if the limit is 50 KB. Choose JPG as the output format.
- If the portal states a pixel width, turn on Limit width and type it. Otherwise let the tool decide: it keeps the highest quality that fits and shrinks the dimensions only if it must.
- Drop the photo, compress, and download the .jpg file.
- For the signature, open Image to 20 KB, type 18 as the target, choose JPG, drop the cropped signature and download.
- Upload both, and keep the originals in case the portal rejects a file.
What if the portal says my file is too small?
Ranges have a floor, such as 10–20 KB or 54 KB. A tightly cropped signature on white paper can come out at only a few KB. Start again from the original photo or scan, not the compressed copy, crop with a little more margin, and set the target near the top of the range (18 KB for 10–20 KB). The tool never upscales and never returns a file bigger than the one you gave it, so if the original is already under the minimum, rescan it at a higher resolution.
Why is my file rejected when its size is right?
- Wrong format. iPhones save photos as HEIC by default, and most portals want JPEG. Compress with JPG as the output, or switch the camera to JPEG under Settings > Camera > Formats > Most Compatible.
- Pixel dimensions outside the range. Some forms check width and height as well as KB; set Limit width to the stated width.
- KB counted differently. Some sites use 1,000 bytes per KB, others 1,024; a margin of a few KB avoids the problem. See converting a photo from MB to KB.
- Wrong shape. A square visa photo or a wide signature box will reject a tall image; crop first.