Most people who need to compress PDF to 150KB are holding a marksheet. Single-sheet fields usually stop at 100KB and short bundles at 200KB, so 150KB turns up where a form expects one examination sheet, or a year’s two semester sheets joined into one file. The question is how much of a scan survives when one or two pages share 153,600 bytes, and for ordinary printed sheets the answer is nearly all of it.
The size box on this page already reads 150, so adding the file is the only step. The compressor repacks the structure first, lowers the quality of the embedded scans only if that was not enough, and reports which of the two got the file under the cap. Below: the one portal rule for 150KB checked against its own guide, what a page keeps at this weight, and how to meet a band such as 50KB to 150KB.
Before and after
scan-2-pages.pdf
2 pages665 KBPDF
scan-2-pages-compressed.pdf
2 pages147 KBPDF
This 2-page scanned PDF was 665 KB. With the limit set to 150KB, it came out at 147 KB, which is 78% smaller.
Only the photos inside the file were re-compressed. The pages keep their size, and any text in the file stays selectable.
The numbers are from a real run of the tool above. The pictures are previews of the first pages of the actual files.
How to use it
- Drop the marksheet or certificate PDF on the box, or tap it and choose the file.
- Compression starts on its own with 150KB as the ceiling; nothing needs typing unless the field also has a floor.
- Read the result card: the stage used, the page count and the size before and after.
- Open the preview at full zoom on the marks column or the certificate number, then download and upload the file.
Where a 150KB rule is written down
The recruitment portal of the CSIR-National Chemical Laboratory publishes a guide to its application form that spells the figure out. Enclosures must be in PDF format, and its table of maximum file sizes gives 150KB for the SSC/Matriculation/10th marksheet, for each year of graduation marksheets, for both years of post-graduation and for the PhD, while an experience certificate may go to 1MB. The guide also asks for one combined PDF file for all the mark-sheets of a given year, so two semester sheets have to share the 150KB between them.
Elsewhere the figure tends to sit on picture fields rather than document fields. The Indian Air Force Agniveervayu registration, for instance, wants the 10th passing certificate as a JPG/JPEG of 50 kb to 150 kb and the signature in the same format at 80 kb to 150 kb. A PDF of any weight is refused on a field like that.
What one or two scanned pages keep
A greyscale A4 page scanned at 150 DPI arrives as a JPEG of roughly 150KB to 400KB, so a single marksheet needs only a modest drop in JPEG quality, and the marks column and the controller’s signature stay crisp. Two pages leave about 75KB each, still enough for printed figures; the thin lettering around a round stamp and any pale security print are the first to soften, and the compressor scales both pages down a little if quality alone does not get there.
A third scanned page is where 150KB starts to bite. The tool tries lower qualities and smaller pixel sizes before it redraws every page as a picture, and for three colour pages that final stage is likely. A marksheet downloaded from a results portal behaves differently: its words are stored as text and only the logo and the photograph are pictures, so it usually lands under the cap after the first stage with the text still selectable.
Reading the figure the way the portal counts it
On this page 1KB is 1,024 bytes, so the ceiling is 153,600 bytes, the arithmetic Windows and most upload scripts use. A portal that counts in round thousands would report the same file as 153.6KB; if its error message shows sizes with a decimal point, enter 146 in the box and run the file again.
The limit is applied to the whole file, never per page. A notice that gives 150KB per document, with a field for each sheet, wants the pages split and compressed one at a time. A single field for the whole bundle wants the sheets merged first and the merged file compressed once, because that is the file the portal will weigh.
Frequently asked questions
- Can a PDF reach 150KB without losing quality?
- A typed document, yes: the first stage rewrites the file structure and the second touches only the pictures, so the text is left as it was. A scan is a picture through and through and has to give up some JPEG quality; at one or two pages the loss shows only under heavy zoom.
- How do I get two semester marksheets into one 150KB PDF?
- Scan both in greyscale, join them with the merge tool, then drop the merged file here. Compressing each sheet to 150KB first and merging afterwards would produce a file of about 300KB.
- The notice says 50KB to 150KB. How do I stay above the floor?
- Tick “My form also has a minimum size” beneath the size box and type 50. The compressor still aims at 150KB and keeps the best quality that fits. A small typed file that would fall under 50KB is padded with unused data that no viewer displays.
- I have a JPG and the field wants a PDF under 150KB. Is this the page?
- Not for the first step, since this page takes a PDF in. The image to PDF tool wraps a JPG in a page and accepts a size cap at the same time, so set 150 there and the finished file is measured against it.
- The field refuses my PDF and asks for a JPG of 50KB to 150KB. What now?
- Some portals take certificates only as pictures. Turn the page into a JPG with the PDF to JPG tool, then bring it to the image compressor with 150 as the maximum and 50 as the minimum.
- Can I go the other way, from 150KB up to 200KB or 1MB?
- Yes, but not here. The increase PDF size page adds weight inside the file until it reaches the minimum you type, without touching a page.