Compress a PDF to 100 KB or 200 KB, and pass the portal check

For a 200 KB limit, type 200 in the size target box, or use the 200 KB page, which opens with that number already set.

What fits in 100 KB, and what does not

Before you press the button, know whether your file can get there. These are real results from our test files: a lease scanned at 300 dpi in colour (about 1.8 MB a page), 5 phone photos, a 2-page scanned CV, and a 500-page text document. Sizes after compression are in the target’s units, 1 KB = 1,000 bytes.

The rule of thumb behind the table: at the strongest setting a scanned A4 page costs about 19 KB, so 100 KB holds about 5 pages and 200 KB about 10. Notice the 3-page scan coming out smaller than the 1-page one at 100 KB: the tool keeps the gentlest setting that fits, so the single page kept more detail (72 dpi against 50 dpi).

Compress to 100 KB, step by step

1. Check the page count first. More than 5 scanned pages for a 100 KB limit, or more than 10 for 200 KB, will not fit legibly. Go to the next section before you start.
2. Drop the PDF on the tool above, or tap to pick it from your phone’s files. It opens in your browser.
3. Leave the target at 100, or type the number your portal names. The KB and MB buttons switch the unit.
4. Press Compress. The tool searches its 8 settings, from pictures at 300 dpi down to 50 dpi with lower JPEG quality at each step, and keeps the gentlest one that fits. The preset buttons do not matter while a target is set. A file already under the target comes back untouched.
5. Read the result. It says the size before and after and the setting it ended on, for example “Under 100 KB (58 KB) with 60 dpi pictures at quality 35, the best quality that fits”. If it could not reach the target, it says so and how close it got.
6. Open the downloaded file and zoom to the smallest text you need the reader to see. Then upload it.

When the file has too many pages

Page count is the lever that matters most at 100 KB, because every page carries its own picture.

• Remove what the portal does not ask for. A blank back side, an instruction page, the cover letter you upload elsewhere: Delete pages takes them out, then compress what is left.
• Upload in parts when the portal has several fields. A 10-page document as 2 files of 5 pages fits 100 KB per file. Split PDF cuts every N pages or by ranges such as 1-5, 6-10.
• Rescan at a lower resolution if you still have the paper. A scan made at 150 dpi in grayscale starts smaller than a 300 dpi colour scan, so less detail has to go on the way down.

Grayscale is the trick most guides lead with, and our measurements do not back it up for documents. On the 10-page colour scan of a black and white lease, grayscale before the 100 KB target gave 184 KB instead of 198 KB: 7 percent, still over. Colour costs little once a scan is compressed hard. The guide to grayscale covers where it does pay off, which is colour photos you do not need in colour.

Mind the bytes: 100,000 or 102,400

Some portals count 1 KB as 1,000 bytes, some as 1,024, and almost none tell you which. A file of 101,000 bytes passes one and fails the other. The target here counts 100 KB as 100,000 bytes, the stricter reading, so a file that passes here passes either way. If you want to check yourself, your computer’s file properties show the exact size in bytes; the guide to PDF file sizes shows where to look on each device.

What 100 KB cannot do

A 10-page colour scan will not reach 100 KB with readable text; the strongest setting gave 198 KB on ours, and the tool says so instead of pretending. At that point the honest options are fewer pages, parts, or a question to the portal’s support desk about uploading in several files.

A small file is not always a legible one. At 60 dpi an A4 page is about 500 pixels wide: headings and normal type read on screen, small print, stamps and handwriting get soft. The tool picks the gentlest setting that fits, but it cannot invent detail, so look at the result before you upload it, and keep the original.

A text-only PDF does not shrink, because its size is text and fonts, which this tool keeps as they are. Our 500-page text file stays at 117 KB on every setting. If that is your file, remove pages; there is nothing else to squeeze. For the typical caps by portal type, see PDF size limits by portal, and for how low a file can go in general, how small a PDF can get.