JPG, PNG or WebP: Which Format for Form Uploads?
When a form rejects your image "for the wrong format", it usually means it wanted a JPG and you gave it something else. Here is what the three common formats actually do and which to use.
JPG / JPEG — use this for forms
JPG is built for photographs. It compresses smoothly to small file sizes, which is exactly why exam and job portals ask for it — a passport photo fits under 20–50KB easily as a JPG. The trade-off is that JPG is "lossy" (it discards some detail to save space), but for a small form photo that is invisible. If a form does not say otherwise, use JPG.
PNG — great quality, wrong tool for photos
PNG is lossless and supports transparency, which makes it ideal for logos, screenshots and line art. But photographs saved as PNG are several times larger than the same image as JPG, so they usually blow past a form's KB limit. A few portals (some NTS tests) accept PNG, but it is rarely the best choice for a photo upload.
WebP — modern and small, but poorly supported by forms
WebP is a newer format that compresses even better than JPG. It is excellent for websites, but most government portals do not accept it yet, so avoid uploading WebP to an application form even though it produces a smaller file.
What about HEIC (iPhone photos)?
iPhones save photos as HEIC by default. Almost no form accepts HEIC, which catches a lot of applicants out. Convert it to JPG before uploading — when you compress the image in imageto10kb and choose JPEG as the output, the conversion happens automatically.
How much smaller is JPG, really?
The difference is dramatic. A typical passport-style headshot might be around 1,500KB as a PNG but only 120KB as a JPG at the same dimensions — roughly ten times smaller — with no visible difference at that size. That is the whole reason forms standardise on JPG: it lets them accept a clear photo while keeping the file tiny. Try to squeeze a PNG under a 20KB limit and you will usually have to shrink the image so much that it looks blocky, whereas a JPG reaches 20KB while still looking clean.
Does converting to JPG lose quality?
Technically yes — JPG is a "lossy" format, meaning it throws away information the eye is unlikely to notice. In practice, for a small document photo the loss is invisible. The one thing to avoid is converting the same image to JPG over and over (open, edit, save, repeat), because each save compounds the loss and eventually you get visible blocky patches called artifacts. Keep your original photo, and export to JPG once at the size you need.
What about signatures?
Signatures are the exception where you might expect PNG to win, since they are black lines on white. But forms still want JPG, and a signature compresses to well under 10–20KB as a JPG without trouble. Scan or photograph it on plain white paper, convert to JPG, and set the size — there is no need for PNG here.
How to check what format your file is
On a computer, the file extension at the end of the name tells you: .jpg/.jpeg, .png, .webp or .heic. On a phone it is less obvious, which is why so many uploads fail — a photo that looks normal may quietly be a HEIC or WebP file. When in doubt, run it through a compressor set to JPEG output and you will know the result is a valid JPG.
How to convert
You do not need separate software. Open your image in imageto10kb, set "Output format" to JPEG, choose your target size, and download — the file is now a correctly sized JPG ready to upload.
💡 Rule of thumb: forms want JPG. Keep PNG for graphics with sharp edges or transparency, and skip WebP and HEIC for uploads.