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PDFHive

Compress image to KB

Reduce a photo's size in KB to fit an online form. Type the limit and PDFHive finds the best quality that fits, showing the final size in KB and pixels before you download.

Your files are processed in your browser and never leave your device.

How to use Compress image to KB

  1. Click "Select image", or drag a JPG, PNG, WebP or iPhone HEIC image into the box.
  2. Type the size limit in KB. If the form gives a range, tick "Also set a minimum" and type that too.
  3. Click "Compress image" and check the preview, the new size in KB and the size in pixels.
  4. Click "Download JPG" and upload the file to your form.

How to reduce a photo's size in KB for an online form

Exam, job, university and government forms often only accept photos and signatures under a set size, such as 20 KB or 50 KB, while a phone photo is usually several megabytes. PDFHive works as an image size reducer: it saves your image as a JPG at the best quality that fits under your limit.

It first lowers the JPG quality a little, which is hard to see. If that isn't enough, it makes the picture smaller in pixels rather than letting it turn blocky. In our tests, a 4000 × 3000 phone photo came to 49 KB at 664 × 498 pixels, still sharp on screen.

Compress an image to an exact size range

Some forms set a minimum as well as a maximum, for example "between 20 KB and 50 KB". Tick "Also set a minimum" and type both numbers: PDFHive keeps the file inside the range, raising the quality if the image would otherwise be too small.

A very small or simple picture sometimes can't reach the minimum even at full quality. In that case PDFHive tells you the largest size it can make, and the best fix is to start from a larger original.

What if your photo won't fit the KB limit?

If the result doesn't fit, the message under the preview says why. Here is what to do in each case.

  1. "This is the smallest it can go": crop the photo to just what the form needs, such as your face or the document, with Crop image, then compress again.
  2. "Can't be made as large as…": the form sets a minimum size and the picture is too small or too plain. Use the original full photo rather than a small copy.
  3. An iPhone photo (HEIC) takes a moment longer: it is turned into a JPG first. If it can't be read, the file may be damaged.
  4. The form also asks for exact pixels: use Resize image, which sets the pixel size and a KB limit together.

Frequently asked questions

Are my photos uploaded to a server?

No. PDFHive compresses your image inside your web browser, on your own computer or phone. The photo is never sent to us or anyone else.

Is it free?

Yes. It is free to use, with no sign-up, no watermark and no limit on how many images you compress.

Is 20 KB the same as 20,000 bytes?

It depends on who is counting: some websites treat 20 KB as 20,000 bytes and others as 20,480 bytes. PDFHive aims for the smaller number, 20,000 bytes, so your file is accepted whichever way the form checks it. The same goes for every other limit you type.

Why is my picture smaller in pixels after compressing?

Very small limits can't hold a large photo at good quality. Rather than making the picture blocky, PDFHive reduces its width and height until it fits. Forms that ask for 20 or 50 KB almost always expect a small picture anyway, and you can see the exact pixel size before you download.

Why does my photo look blurry at a very small size?

At 20 KB or less, there is only room for a small picture. Crop the photo to just what is needed, such as your face or your signature, before compressing: the same KB then holds more detail where it matters.

What happens to the location and camera details in my photo?

They are removed. Phone photos often carry hidden details such as where and when they were taken. The compressed JPG contains only the picture, which also helps keep the file small.

Which image types can I use?

JPG, PNG, WebP and iPhone HEIC photos. The result is always a JPG, because that is what almost every form accepts and it is the smallest format for photos.

Does it work on my phone?

Yes. Pick a photo straight from your gallery, compress it, and the JPG is saved to your Downloads or Files app, ready to upload.

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