A 400KB ceiling is rarer than 200KB or 500KB, but it does appear on some university admission sites and state-board verification portals, usually on the field for a marksheet, a migration certificate or a caste certificate. The file involved is nearly always a scan of three to five pages, made with a phone or an office copier, that arrived at a megabyte or more and was refused.
The maximum on this page is already filled in at 400KB. Add the PDF and the compressor starts on its own, working through its three stages until the finished file measures 409,600 bytes or fewer. The result card names the stage that did it, gives the page count and shows the size before and after.
How to use it
- Drop the scanned PDF on the box above, or tap the box and choose it from your files.
- The compressor runs as soon as the file lands, with 400KB as a hard ceiling.
- Read the result card to see whether only the structure changed or the scans were re-compressed.
- Zoom into the smallest print, such as a seal or a roll number, before you upload.
What a four-page scan keeps at 400KB
A phone scan of four A4 pages usually starts between 2MB and 8MB, because each page is stored as one large colour photograph. Bringing that under 400KB leaves roughly 100KB a page, which is comfortable for greyscale typed text and adequate for a colour page carrying a photograph and a signature. The compressor lowers the JPEG quality of each page image in measured steps, testing the whole file after each, and reduces the pixel size only when quality alone cannot get there. Faint pencil marks and pale stamps are the first things to soften.
Colour photographs inside a typed PDF
A form exported from Word with real text and a pasted passport photograph is treated differently from a plain scan. The second stage touches only the embedded pictures: the photo is re-saved at a lower JPEG quality and scaled down if needed, while every letter, table rule and form field stays as it was and can still be selected and searched. A two-page application that reached 1.5MB because of a 4MB photograph typically drops to a few hundred kilobytes with no visible change on the page.
Frequently asked questions
- My scan is 380KB already. Will this page still re-compress it?
- No. The size is measured first, and a file already at or under 409,600 bytes is reported as fitting and offered back unchanged. Squeezing it further would cost quality without helping the upload.
- Is 400KB here 400,000 bytes or 409,600?
- It is 409,600, because the compressor counts 1KB as 1,024 bytes, the way Windows and most upload scripts measure a file. If your portal’s error message quotes sizes in round thousands, type 390 in the size box and run it again so the result passes either count.
- When would the pages be saved as pictures?
- Only if the file still misses 400KB after the photographs have been squeezed, which is rare for three to five pages. The card says so when it happens; the page size in centimetres is kept, but the text has become part of the image and a portal that extracts text from uploads cannot read it.
- The portal wants all five certificates in one file. What order should I work in?
- Merge them first and compress the merged file, so the 400KB budget is shared across every page the way the portal will measure it. Compressing each certificate to 400KB and then merging would give a file five times too heavy.