About this tool
This is the tool for the moment a form says the photo must be under 50 KB and your phone has just handed you a four-megabyte file. Instead of nudging a quality slider and checking the result each time, you type the number the form gave you and let the tool work backwards from it.
What happens inside is a search. The picture is encoded as a JPEG at a middling quality, the result is weighed, and the quality moves up or down depending on whether it fit. Ten rounds of that settle on the highest quality that still comes in under your ceiling. Dimensions stay untouched the whole time, which matters more than it sounds: a form that caps file size usually specifies width and height too, and a photo that passes one check while failing the other gets you nowhere. Only if no quality setting is low enough does the tool begin reducing resolution, a fifth at a time, and it reports the dimensions it finished with.
So there are two numbers to read on the result, not one. The new file size should sit just below your limit. The output size in pixels should match whatever the form states. If it does not, set the dimensions first with the resizer or the cropper, then bring the file back here for the size.
None of this involves a server. The photo is decoded in your browser, re-encoded by your own processor and handed back as a download. That is why it works on two bars of mobile signal, why there is no queue, and why no copy of your photograph exists anywhere once you close the tab.
How to use this tool
- Choose your photo. A JPG, PNG or WebP from your phone or computer, up to 50 MB. It is read straight into the browser, not sent anywhere.
- Type your limit in KB. Whatever number the form asks for. The box starts at 100 and takes anything from 1 to 50,000. One KB here is 1,024 bytes, the same as in your file manager.
- Run the tool. It tries a range of JPEG quality settings and keeps the best one that still fits under your number. On most photos this takes a second or two.
- Read both numbers, then download. You get the old size, the new size and the output dimensions in pixels. Check both against what your form asks for before you upload.
What this tool does not do
- It cannot produce an exact byte count — only a file at or below your limit.
- The output is always JPEG. There is no PNG or WebP option here.
- Transparency is lost, because JPEG has no way to store it.
- It checks no portal's rules. Read your form's own instructions and compare the numbers yourself.
- A very small limit on a very large photo fails with a message rather than handing you an unusable file.
- One image at a time. There is no batch mode.
Common questions
Will the file come out at exactly the size I typed?
No, and that is deliberate. It lands at or below your limit. An encoder cannot be asked for a precise byte count, and upload forms check for “under”, not “equal to”, so just under is the right answer.
Does it shrink the width and height of my photo?
Only when it has no choice. Quality comes down first, right down the range, because forms that cap the file size usually state pixel dimensions as well. Resolution is cut in steps of a fifth only when no quality setting alone can reach your limit, and the result tells you what dimensions you ended up with.
I uploaded a PNG and got a JPG back.
Output here is always JPEG. It is the format that gives real control over file size, and it is what nearly every upload form takes. For PNG or WebP output, use the image converter or the ordinary compressor.
My picture had a transparent background and it has turned white.
JPEG has no transparency, so transparent areas are painted white before encoding. If that transparency matters, this is the wrong tool — compress it as PNG or WebP instead.
It says the size limit could not be met.
That is a very small limit against a very large picture: 5 KB on a twelve-megapixel photo, say. Crop or resize the image down first and come back, or raise the limit if your form allows it.
Should I go well under the limit to be safe?
No. Land as close under it as you can. A 200 KB cap met with a 190 KB file looks far better than the same photo forced down to 40 KB, where faces and hair turn blocky.