How to compress a JPG to 100 KB, 50 KB or another exact size
Job portals, university forms and government sites often refuse a photo or scan unless it is under a certain size, such as 100 KB, 50 KB or even 20 KB. A photo straight from a phone is usually several megabytes, so it needs to shrink a lot without becoming unreadable.
Compress image lets you type the size you need and shows the size it actually reached. It runs in your browser, so your photo stays on your device and is not uploaded to PixnPDF.
Find the exact limit first
Read the upload instructions and note the maximum size and the accepted formats. Some forms also give a minimum size or exact pixel dimensions. Use the form's own numbers; they are the only ones that matter for that upload.
Remember that 1 MB is about 1,000 KB. A 3 MB photo that must go under 100 KB needs to lose about 97% of its bytes, which is normal for a photo but needs the right approach.
Shrink the pixels before the quality
File size depends mostly on how many pixels the image has. A phone photo can be 4,000 pixels wide, while a form usually displays a few hundred. Use Resize image first to bring the longest side down to a sensible size, for example around 1,000 to 1,500 pixels for a document photo, or the exact dimensions the form asks for.
Crop away background you do not need with Crop image. Every pixel you remove is a pixel you do not have to compress, so the remaining detail can keep better quality.
Set a target size
Open Compress image, choose the target file size option and enter the number you need in KB. The tool tries to reach it and then shows the real output size next to the original, so you can see whether it worked. Targets are best effort: if a file cannot reach the number at all, you will see the closest result rather than a false promise.
If an image is already smaller than your target, the original is kept, because making it larger would be pointless. Compare the before and after previews side by side before downloading.
Pick the right format
JPG is usually the smallest choice for photos. PNG is better for screenshots, logos and drawings with flat colours, but a PNG photo is often far larger than the same photo as JPG. If a form accepts JPG and your file is PNG or HEIC, convert it with Convert image first and then compress.
WebP and AVIF can be smaller still, but many forms do not accept them. Only use them when the upload page lists them.
Check that it is still readable
Open the result at full size. Faces should be clear, and any text, such as a name or number on a document, must be readable. If the image looks blocky, raise the target size a little or resize to slightly larger dimensions and try again.
Keep your original photo. The compressed version is a copy for the form, not a replacement.
How it works
- Note the form's maximum size, accepted format and any pixel dimensions.
- Resize the photo so its longest side is closer to what the form needs, and crop extra background.
- Open Compress image, choose target file size and enter the KB you need.
- Compare the real output size and the preview, then download.
- Open the downloaded file at full size before you upload it.
Before you export A very small target can make text and faces unreadable. If you cannot reach the limit at a readable quality, resize smaller first rather than forcing heavy compression.
Common questions
Is my photo uploaded to compress it?
No. Compress image runs in your browser and the photo stays on your device.
Why did my image not reach the exact size?
Targets are best effort. Very large or detailed photos may need resizing to smaller pixel dimensions before they can reach a small target.
Can I compress several photos at once?
Yes. Add several images, set the target and download them together.
What is the difference between KB and MB?
One megabyte is about 1,000 kilobytes. A form that says 0.1 MB means about 100 KB.