How to compress an image to 100KB
Add your image by dragging it onto the box or selecting “choose files”. The target is already set to 100 KB, so you do not need to change anything.
Keep the original format if the site you are uploading to asks for JPG or PNG. Most forms that set a 100 KB limit expect a JPG.
Download the result and look at the size shown next to it. It should read 100 KB or less. Open the file once to check that faces and text are still clear before you submit it.
If you need a different limit, choose another preset or enter a custom size. The same tool also handles 20 KB, 50 KB and 200 KB.
Where a 100 KB limit usually comes from
A 100 KB cap is one of the most common upload limits on the web. You meet it on job application portals that ask for a profile photo, on visa and travel application forms, on public-service websites that want a scanned document, and on school or membership sign-up pages. The limit keeps their storage and review queues small, and it is rarely explained on the page — the form simply rejects anything larger.
Email is the other place where size matters. A single phone photo can be 3–8 MB, and attaching several can push a message over the recipient’s limit or make it slow to open on mobile data. Compressing photos to around 100 KB each keeps them perfectly readable on screen while making a whole set small enough to send in one message.
Whatever the form, read its requirements in full before you compress. Many portals combine a size limit with a required format (usually JPG), minimum or exact pixel dimensions, a plain background for photos, or a rule against edited images. Compressing changes only the file size, not the content of the picture.
What fits in 100 KB
100 KB is generous for a single photo. As a rough guide, a typical photo with a lot of detail can keep around 1,400–1,600 pixels on its longer side at a good JPG quality and still fit, and a simple image with large flat areas can be larger still.
That means a modern phone photo, which is often 4,000 pixels wide or more, will usually reach 100 KB only if quality drops a lot — and if even the lowest quality is too large, the tool reduces its dimensions to make it fit. If the result looks soft or blotchy, reduce the image’s dimensions to about 1,200–1,600 pixels wide, with the maximum width setting or in a photo editor, then compress it again. You will get a sharper result at the same size.
For a scanned document, contrast matters more than resolution. A clean, straight scan with a white background compresses far better than a phone picture of a page taken at an angle under a lamp.
Tips for a sharp 100 KB file
Crop before you compress: everything outside the face or the page is wasted bytes. Use JPG for photos and scans that a form will accept as JPG; PNG photos are much harder to bring under 100 KB. Avoid compressing the same file again and again — start from the original each time, because each pass removes a little more detail. And keep the original somewhere safe in case a portal later asks for a higher-quality version.