How to make a photo meet an application portal’s pixel and file-size rules

Write down every rule before you start editing. They usually fall into four groups:

• Format: almost always JPG or JPEG. Some accept PNG. Few accept WebP or HEIC.
• Dimensions: an exact size (600 × 600), a range (between 350 × 450 and 1050 × 1350), or a ratio (“square”, “35 × 45 mm”).
• File size: a maximum (under 240 KB), and sometimes a minimum (at least 20 KB). A minimum exists to stop people sending tiny, unrecognisable thumbnails.
• Content: background colour, face position, no glasses, recent photo. No tool can fix these after the fact, so get the photo right when you take it.

The order you work in matters: crop to the right shape, then resize to the right pixels, then compress to the right file size.

QuickConvert’s Image Resize does not crop. If you switch off “Keep aspect ratio” and type 600 × 600 for a 3000 × 4000 portrait, the tool will squeeze the photo into a square and your face will look wider. That is the most common reason a photo gets rejected as “distorted”.

So crop first, using the editor built into your phone or computer:

• On iPhone, open the photo in Photos, tap Edit, then the crop icon, then the aspect-ratio button and choose Square (or another ratio the portal asks for).
• On Android, most gallery apps have a crop tool with fixed ratios such as 1:1 and 3:4.
• On Windows, the Photos app has Crop with preset ratios. On a Mac, Preview’s rectangular selection shows the size as you drag, then Tools › Crop.

If the portal states a size in millimetres, convert it to a ratio. 35 × 45 mm is a ratio of 7:9. 2 × 2 inches is square. Crop to that ratio and leave a little space above the head, as most photo rules require.

Open Image Resize and drop the cropped photo. Wait until the original size appears; the width and height boxes are filled with the real numbers.

• Choose Dimensions and leave Keep aspect ratio on.
• Type the target width, for example 600. Because you already cropped to a square, the height also becomes 600.
• If the height comes out as 601 or 599, your crop was not quite square. You can switch the ratio off and type both numbers, because a one-pixel difference will not visibly distort the photo.
• Set Save as to JPG and leave quality at 90 for now.
• Click Resize and download.

For a ratio such as 7:9 with a required width of 420 pixels, the height is 420 ÷ 7 × 9 = 540. Typing 420 with the ratio on will produce 540 if the crop was accurate.

A 600 × 600 JPG at quality 90 is often already under 200 KB, but it depends on the photo: a busy patterned background takes more bytes than a plain wall. Check the size of the downloaded file. If it is above the limit, use Image Compress:

• Drop the resized JPG.
• Set Output format to JPG.
• Turn off “Cap long edge”, or set it to the exact width you already have. You do not want the compressor to change the dimensions you just set.
• Start the quality slider at 80, click Compress and download, and read the before and after sizes in the list.
• If it is still over the limit, try 70, then 60, always starting from the resized file rather than from a previous compressed copy.

Look at the face at 100 percent zoom after each attempt. Blocky patches on the skin or around the eyes mean the quality is too low. For a 600 × 600 photo, there is rarely a reason to go below about 60.

When the file is too small

If the portal requires a minimum such as 20 KB and your file is 14 KB, raise the quality in Image Compress (90 or above) or resize to the larger end of the allowed pixel range. Do not upscale a tiny photo to reach the minimum; it will pass the check but look soft. Start from the original instead.

Many portals also ask for a scanned signature, with rules like 140 × 60 pixels and under 20 KB. The same steps apply:

• Sign in dark ink on plain white paper, photograph it in good light, and crop tightly around the signature at the required ratio. 140 × 60 is 7:3.
• Resize to the exact width with the ratio on.
• Save as JPG if JPG is required. A signature on a white page has little detail, so it usually ends up only a few kilobytes even at high quality.

If you photographed the signature on a slightly grey sheet, JPG will keep that grey. Better lighting at the photo stage helps more than any later setting.

A portal asks for a JPG photo, 600 × 600 pixels, between 20 KB and 240 KB. The phone photo is a 3024 × 4032 HEIC.

• Convert the HEIC with HEIC to JPG, or on iPhone save the photo to the Files app and use Quick Actions › Convert Image. For future photos, Settings › Camera › Formats › Most Compatible saves JPG from the start.
• Crop to square in the Photos app. The crop is now roughly 3024 × 3024.
• In Image Resize, Dimensions, ratio on, width 600, Save as JPG, quality 90. The result is 600 × 600.
• Check the file size. If it is 180 KB, you are inside the range and finished. If it is 260 KB, run Image Compress at quality 80 with the long-edge cap off.

An application photo and a signature are exactly the kind of files you should not leave on a random converter’s server. QuickConvert’s image tools work in your browser. The image is decoded, redrawn, and saved on your device and is not uploaded to QuickConvert. The privacy guide explains what the page itself still loads.

Why does my photo look stretched after resizing?

The ratio was switched off and the target shape did not match the photo. Crop to the right shape first, then resize with Keep aspect ratio on.

Does resizing change the DPI the portal asks for?

Portals that mention DPI almost always check pixel dimensions in practice. A 600 × 600 image is 2 × 2 inches at 300 dpi. If a portal truly validates the DPI field in the file, check its instructions, as browser-based resizing writes a standard JPG without a custom DPI value.

Can I use PNG instead of JPG?

Only if the portal says so. PNG files of photos are usually much larger than JPGs, so they are more likely to break the KB limit.

My phone saves photos as HEIC. Can QuickConvert open them?

Image Resize, Image Compress, and Image Convert do not read HEIC. Convert the photo with HEIC to JPG, then resize or compress the JPG.

Ready to start? Crop the photo, then open Image Resize.