How to reduce a PDF's file size, and what you give up
Getting a 9 MB PDF under a 2 MB upload limit, and knowing the cost
Under the upload box on the application form there is a small line of grey text: "PDF, max. 2 MB". Your file is 9 MB. When you press Submit, either a red warning appears or the page quietly refuses the file. This guide is written for that exact moment: why the file is so large, what gets sacrificed when you shrink it, and which setting brings it under the limit.
The good news first: when an application PDF weighs 9 MB, the weight nearly always comes from one source, and that source can be shrunk. The less pleasant news: every way of shrinking a PDF costs something. Know in advance what each method costs, and the organisation will not receive a file that is unreadable or missing something.
First, the diagnosis: what is inflating your file?
A PDF is a container. Text, fonts, drawings and photos can all sit inside it, and the size depends on which of them dominates. You do not need any extra software to find out; two quick checks are enough.
Check one: open the document, hold the left mouse button at the start of a line and drag to the right. If the words are highlighted one by one, the document was typed on a computer. If nothing highlights, or the whole page turns blue as a single block, you are looking at a scan, in other words a photograph of the page. On a phone, do the same test by pressing and holding a word.
Check two: divide the file size by the number of pages. Windows shows the size under Properties, in the menu you get by right-clicking the file; a Mac shows it once you select the file and press Command and I together. The page count is shown in the toolbar while the PDF is open. A 9 MB file with 4 pages carries more than two megabytes per page. Plain text cannot account for that much; those pages contain large photos or high-resolution scans.
- Text will not highlight and each page weighs megabytes: a scanned document, and shrinking will pay off handsomely
- Text highlights but the pages contain photos: a mixed document, the photos shrink and the text stays as it is
- Text highlights, there are no photos, and it is still heavy: the weight sits in fonts or drawings, so gains will be modest
Why does a scanned page take up so much space?
When a scanner or a phone app reads a page, it divides it into millions of tiny dots called pixels. Scan an A4 sheet at 300 DPI and you get an image of 2480 × 3508 pixels: roughly 8.7 million dots, each carrying its own colour value. Even if the page is black text on white paper, a colour scan still records three colour channels for every dot. Across a four-page document that adds up to more than thirty million dots. US Letter paper is slightly smaller than A4, but the numbers land in the same range.
Fonts, on the other hand, are rarely to blame. A font embedded in a typed document is a description of letter shapes, and it is not stored again on every page. If your file consists of scanned pages, most of its weight is in the images and you can stop worrying about fonts.
The table below shows how many dots the same A4 page holds at different resolutions. The last two rows show where a scanned A4 page ends up with the Balanced and Strong settings of this site's Compress PDF tool, which caps the long edge of each image at 2200 or 1600 pixels.
| A4 page | Pixel dimensions | Dots (approx.) |
|---|---|---|
| Scanned at 600 DPI | 4961 × 7016 | 34.8 million |
| Scanned at 300 DPI | 2480 × 3508 | 8.7 million |
| Scanned at 200 DPI | 1654 × 2339 | 3.9 million |
| Compress PDF, Balanced | 1555 × 2200 | 3.4 million |
| Compress PDF, Strong | 1131 × 1600 | 1.8 million |
What does shrinking take away? Three steps, three prices
There are three ways to make a PDF smaller. Each is stronger than the one before it, and each costs more. The two tools on this site stop at different points along the way, so the right choice depends on what you are willing to lose.
The Compress PDF tool stays on the first two steps and never turns a page into a picture, whatever the setting. Text remains selectable, searchable and copyable. It re-encodes only photos and scans that are stored as JPEG. It leaves PNG-style images such as screenshots untouched, and it does not touch fonts either, which is why the gain is small on that kind of file.
The target-size tool goes down to the third step when it has to: it turns every page into a single photo and rebuilds the document from those photos. That step can bring almost any file down to the size you need, but the price is steep. Text can no longer be selected or searched, and links and fillable fields on the page disappear. The hidden searchable text layer that some scanning apps place behind the image is wiped out too.
This third step is switched on by default. If you need the text to stay selectable, set "If images are not enough" to "Shrink as far as possible". The tool then stops at step two and tells you plainly if it could not reach the target.
Which tool and which setting for a 2 MB limit?
The right starting point depends on what kind of document you have and what the form asks for. The table pairs the most common situations with the first move to try; if that is not enough, look at the next row down.
| Your situation | First move |
|---|---|
| A few pages scanned with a phone | Compress PDF on Balanced; if it is still over the limit, Strong |
| The form states an exact limit (2 MB, 500 KB and so on) | Target-size tool: pick Custom and type the limit in KB |
| The text must stay selectable (contract, paper) | Target-size tool with "Shrink as far as possible", or Compress PDF |
| A Word export full of screenshots | Compress PDF will not shrink those images; the target-size tool gets there by turning pages into images |
| Several separate PDFs to shrink | Compress PDF; you can select them all at once |
| You have tried everything and it is still too big | If the form allows it, split the document and upload the parts separately |
Still too big? Leave a margin and go back to the source
Forms can count megabytes differently: some treat 1 MB as 1024 KB, others as 1000 KB. The tools on this site use 1024. Do not aim for the exact limit; in the target-size tool pick Custom and type a slightly lower value such as 1900. That removes the risk of being rejected right at the edge.
If you can redo the scan, that is where the real savings are. In your scanner software on the computer, or in the settings of your phone's scanning app, lower the resolution to 200 DPI and switch the colour mode to greyscale. Scanning a black-and-white document in colour writes colour information into the file that serves no purpose. If you created the document in Word yourself, choose PDF in the Save As dialog and set "Optimize for" to "Minimum size (publishing online)" before saving.
For a long document that will not fit into one file at all, the last resort is splitting it. If the form offers several upload boxes, the Split PDF tool can cut the document into equal parts, one for each box. If there is only one box, that route is closed, and the target-size tool's page-to-image step is the realistic option left.
Three checks before you upload
The file is now under the limit. Before you upload it, take one more minute; these checks keep an application from being sent back because a document could not be read.
- Open the smaller file and zoom in: can you still read the ID number, the grades, the fine print inside a stamp
- Read the method in the result line: if it says the pages were turned into images, the text can no longer be selected; decide whether that matters to you
- Keep the original: compressing an already compressed file loses a little more detail every round, so every new attempt should start from the original
Frequently asked questions
Will the text look blurry after I shrink a PDF?
Typed text will not: Compress PDF and the first two steps of the target-size tool leave text alone and only re-encode photos. In a scanned document, though, the text is part of the photograph, so its edges soften as detail is removed. For a document with small print, stay on Balanced and zoom in on the result before sending it.
Why can I no longer select the text in my compressed PDF?
If the target-size tool had to turn the pages into images to reach the limit, the text is now part of a picture; the result line says so. If you need selectable text, run the same original again with "Shrink as far as possible", or use Compress PDF instead.
My file only shrank by a few percent. Why?
If the document contains no JPEG photos that can be re-encoded, there is little weight to remove. Screenshots and drawings are usually stored PNG-style, and Compress PDF deliberately leaves them as they are; fonts stay untouched too. To force such a file under a limit, use the target-size tool's step that turns pages into images.
Can I compress a password-protected PDF?
Not directly: both tools stop when they meet an encrypted file and say so. If you know the password, first make an unprotected copy with the PDF password removal tool, then compress that copy.
Do I have to upload my file somewhere to shrink it?
No. The tools on this site open and shrink the document inside your browser. Personal papers such as an ID card, a degree certificate or a medical report never leave your device.
Last updated: October 12, 2026