Will it always get under 100 KB?

Not always, and it will tell you when it cannot. The search stops at quality 30, because below that a JPEG stops being a smaller version of your photograph and becomes a blocky approximation of it. If 100 KB is unreachable at that floor, you get the smallest sensible file and a clear statement that the target was missed — the fix is then to reduce the dimensions, which is far more effective than pushing the quality lower.

Is my photo uploaded?

No. Every encoding pass runs in your browser, so the file never leaves your device — and there are several passes, all of them local. Nothing about your photograph is sent anywhere.

Why does this take longer than normal compression?

Because it encodes the image several times. Compressing to a fixed quality is one pass; hitting a size target means trying a quality, measuring the result, and narrowing in. It usually settles within about six passes, which is a second or two for a typical photograph.

Can I change the target?

Yes — the field under the result is editable. This page exists because 100 KB is what people search for, but if it turns out your real limit was different, change the number and convert again rather than hunting for another page.

Does the result go slightly over sometimes?

No. The search only keeps results that measure under the target, so what you download is under it. Nothing is estimated — every candidate is a real encode that we measured.

Compress JPG to 100 KB — Free, No Upload

Reaching 100 KB without wrecking the picture

For a typical photograph at web dimensions — around 1200 to 1600 pixels wide — 100 KB is reached at a quality that most people would not distinguish from the original. The search starts high and works down, so you get the best-looking file that fits rather than the first one that does.

Straight off a modern phone at 4000 pixels wide, it is a stretch. The picture is not the problem; the pixel count is. One step down the resize control usually turns a marginal result into an easy one.

What a 100 KB JPG looks like

On most images the result will look, at normal viewing size, like the file you started with. Compared side by side at full zoom you will find softened texture and slightly flattened gradients, which is precisely the detail that costs the most bytes and is noticed the least.

A hundred kilobytes is a good default for a web page image even when nothing demands it. It loads quickly on a slow connection and looks correct on a fast one, which is a better trade than most pages make.

Why a target size is a search and not a setting

A JPEG encoder takes a quality number, not a file size. The relationship between the two depends entirely on the picture — a photograph of a brick wall and a photograph of a clear sky at the same quality and the same dimensions differ in size by a factor of ten, because one is full of detail and the other is nearly empty.

So there is no formula. We encode at a quality, measure the result, and adjust — narrowing in on the highest quality that still fits under 100 KB. It costs a handful of encoding passes, which is why this takes a moment longer than compressing to a fixed quality, and it is the only honest way to answer a question posed in kilobytes.

How to compress a JPG to 100 KB

Drop your JPG onto this page, or click to choose one.
We encode at several qualities and keep the best one under 100 KB, in your browser.
If the target could not be reached, the page says so rather than handing you something unusable.

Compressing to 100 KB: common questions

Will it always get under 100 KB?: Not always, and it will tell you when it cannot. The search stops at quality 30, because below that a JPEG stops being a smaller version of your photograph and becomes a blocky approximation of it. If 100 KB is unreachable at that floor, you get the smallest sensible file and a clear statement that the target was missed — the fix is then to reduce the dimensions, which is far more effective than pushing the quality lower.
Is my photo uploaded?: No. Every encoding pass runs in your browser, so the file never leaves your device — and there are several passes, all of them local. Nothing about your photograph is sent anywhere.
Why does this take longer than normal compression?: Because it encodes the image several times. Compressing to a fixed quality is one pass; hitting a size target means trying a quality, measuring the result, and narrowing in. It usually settles within about six passes, which is a second or two for a typical photograph.
Can I change the target?: Yes — the field under the result is editable. This page exists because 100 KB is what people search for, but if it turns out your real limit was different, change the number and convert again rather than hunting for another page.
Does the result go slightly over sometimes?: No. The search only keeps results that measure under the target, so what you download is under it. Nothing is estimated — every candidate is a real encode that we measured.

Sometimes the better answer is a different format — especially for a photograph stored as JPG.