How to get a file under an upload limit
A method that works for photographs, scans and PDFs: find out how far over you are, cut the dimensions before you touch the quality, and stop when the file is legible rather than when the slider runs out.
- Updated September 2026
- 7 minute read
- With a size calculator
The error message that never tells you enough
“File size exceeds the maximum allowed.” It does not say by how much, it does not say what to do, and it usually appears after you have filled in everything else. So people open the first compressor they find, drag the quality slider to the floor, upload something that looks like it was faxed, and hope.
There is a better order of operations, and it takes about two minutes. Work out the size of the gap first. Reduce the dimensions before you touch the quality. Then compress once, from the original, and look at the result at the size it will actually be seen.
Start by picking where the file is going. The limits below are real ones, checked in September 2026.
How small does it actually need to be?
pick a destinationKnow the gap before you touch anything
The size of the cut decides the method, and the three bands behave very differently.
Under 40 percent
One pass at a sensible quality does it, and nobody will see the difference. A photograph at quality 80 is usually well under half the size of the same photograph at quality 95, and the two are hard to tell apart at normal viewing size.
40 to 80 percent
Quality alone will start to show. Reduce the pixel dimensions first — most photographs are far larger than they need to be for the purpose — and then compress the smaller image.
Over 80 percent
Expect to make a judgement call. Cut the dimensions hard, compress, then look at the result properly. If it is a document, check that the text is still readable rather than just present.
This is why the calculator above shows a percentage rather than a target size. Going from 4 MB to 200 KB is a 95 percent cut, and knowing that up front tells you it is a resize-first job, not a slider job.
Photographs: resize first, compress second
A phone camera produces something like 4000 by 3000 pixels. A passport-style photograph on an application form is displayed at a few hundred pixels. You are carrying roughly a hundred times more pixels than the destination will ever show, and no amount of quality reduction addresses that — it just makes the enormous image blurry.
- Reduce the dimensions to what the form asks for, or if it does not say, to something sensible like 800 pixels on the long edge. This is where most of the weight goes, and it costs nothing visible.
- Then compress, starting around 80 percent quality and lowering it only if you still need to.
- Crop before either. Cropping out the background you do not need removes pixels permanently and improves the photograph at the same time.
- Keep the original. If the result is too aggressive, you want to start again from the full-size file rather than from the damaged one.
The image resizer takes exact pixel dimensions, which is what forms ask for, and the image compressor shows the original and the compressed version side by side with the saving printed underneath.
PDFs: protect the text layer
A PDF is usually large for one of two reasons, and they need opposite responses.
If it was exported from a word processor, the text is real text and the file is big because of embedded images or fonts. Compression will find the images and leave everything else alone, and you will often halve the file with no visible change at all.
If it was scanned, there is no text in it. Every page is a photograph of a page, which is why a ten page scan can be thirty megabytes and why searching it finds nothing. Compression works on those photographs, so the thing to watch is legibility: shrink it too far and the letters develop soft edges long before the file looks obviously wrong.
The check that takes five seconds
Open the compressed PDF and try to select a sentence with your cursor. If the text highlights, the text layer survived and the file is still searchable. If nothing highlights and nothing ever did, it is a scan, and the only question that matters is whether you can still read it comfortably at 100 percent zoom.
The specifications people actually hit
A few limits come up again and again, and they are worth knowing before you start rather than after the form rejects you.
Indian government exam forms
The UPSC online application asks for a colour photograph in JPG between 20 KB and 200 KB, on a plain white background, with the face filling around three quarters of the frame. The signature is JPG between 20 KB and 100 KB, 350 to 500 pixels, signed three times one below the other in black ink on plain white. SSC, IBPS and state commission forms use similar numbers but not identical ones, so read the notification rather than assuming.
Two of those requirements are dimension requirements, not size requirements, which is exactly the case where resizing matters more than compressing. The white background requirement is also why a background remover is sometimes the fastest route — though for a photograph taken against a busy room, retaking it against a wall is faster than any tool.
Email and messaging
Personal Gmail accounts allow 25 MB of attachments per message; anything larger is turned into a Google Drive link automatically rather than failing. Work and school accounts run on whatever the administrator has set, which is often lower. If a file is close to the line, compressing it is usually less friction than explaining a Drive link to the recipient.
Job portals and recruitment systems
Most cap a CV around 2 MB and expect a PDF. A CV should never be anywhere near that, and when one is, the cause is almost always a photograph or a logo that was dropped in at full camera resolution.
When you cannot get there
Sometimes the target and the content are genuinely incompatible, and the honest move is to change the input rather than to keep pushing the slider.
- A dense scan that will not go under 100 KB. Rescan at 200 dpi in greyscale instead of 600 dpi in colour. You will get a smaller and clearer file than any amount of compression can produce from the large one.
- A photograph that turns to mush at the target. Crop it. Fewer pixels of the thing that matters beats more pixels of a wall.
- A PDF full of high-resolution photographs. Compress the images first, then rebuild the PDF, rather than compressing the finished document.
- A form that rejects the file anyway. Check the format before assuming it is the size. A great many rejections are an extension check, not a size check.
Questions about reducing file size
How do I reduce a photo to 20 KB or 50 KB?
Reduce the pixel dimensions first — a photograph that has to fit in 20 KB should not be more than about 400 pixels on its long edge — then compress at a quality around 70 and adjust from there. Trying to reach 20 KB by quality alone, from a full-size camera image, produces a blurry file that is still too big.
Does compressing a PDF make the text unreadable?
Not if the PDF has a real text layer, because compression works on the embedded images and leaves the text alone. A scanned PDF is entirely images, so there the text can degrade — check it at 100 percent zoom rather than trusting the file size.
Why is my file still too large after compressing?
Usually because the dimensions were never reduced. Compression removes detail within the pixels you have; it cannot remove the pixels themselves. If a 4000 pixel image is still too big at quality 60, the problem is the 4000.
Is it safe to compress a document with personal information?
It depends whether the tool uploads it. Anything that processes the file in your browser never transmits it, which removes the question entirely. If a tool does upload, look for a stated retention period before you send anything with an identity number or a signature on it.
What size should a passport photo be for an online form?
Whatever the form says, and the forms differ. UPSC asks for 20 to 200 KB in JPG on a plain white background. Other commissions and universities set their own ranges. The only reliable answer is the one printed in the instructions for that particular form.
Can I compress a file more than once?
You can, but each pass of a lossy format throws away more detail permanently, and the second pass gains far less than the first. If the first result is not small enough, go back to the original and compress harder from there rather than compressing the compressed copy.
In this article
Tools in this article
Check the form, not this page
The limits quoted here were checked in September 2026 and they do change between exam cycles. Where a form states its own specification, that one wins.
Compress it in your browser
Images and PDFs, free, with no account and nothing uploaded to a server.