Compress PDF to 100KB
The PDF compressor below opens in Target Size mode set to 100KB. Add one or more PDFs, press Compress, and download copies at or under 100KB where the pages allow it. Files are processed in this tab and never uploaded.
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This page opens the TryDocsy PDF compressor in Target Size mode with 100KB already entered. It is meant for the strictest document upload fields, where a scanned certificate, an ID proof or a one-page letter has to come in under 100KB. You can add several PDFs at once and each one is compressed towards its own 100KB target.
To reach sizes this small in the browser, the compressor redraws every page as a JPEG image and builds a new PDF from those images. That makes a 100KB goal realistic for a page or two, but it also means the text stops being selectable and the page count largely decides whether 100KB can be reached at all. Both points are explained below so you know what to expect before you upload the result.
How it works
1. Add the PDF
Drop files on the box labelled “Drop PDF files here”, or click it to browse; on a phone the box reads “Drop PDF here”. Each PDF can be up to 100MB. Password-protected files are skipped with a notice, so unlock them first.
2. Check that Target Size shows 100 KB
In the Settings panel the Target Size tab is already active, the size field holds 100 and the KB unit is selected. The Quick presets row also has a 100 KB button if you change the value and want it back.
3. Press Compress
The Compress button starts the job, and the counter on it shows progress through several files. Keep the tab in the foreground while it works. Each file row then shows its page count, the original size, the new size and the percentage saved.
4. Download the compressed copy
Use the Download button (it shows a count when there are several files) or the download icon on a single row. Copies are saved with “-compressed” added to the file name, and the original PDF is left untouched.
When you'd use it
Single-page certificates and ID proofs
Mark sheets, caste or income certificates and identity documents are usually one scanned page, which is the case where a 100KB PDF stays clearly readable.
Application portals with a 100KB document cap
Some online application forms limit each supporting document to 100KB. Compressing to this preset means you are not trying random quality settings while the form session times out.
Short signed letters
A one- or two-page signed declaration or no-objection letter, scanned on a phone, typically starts at a few megabytes. At 100KB the signature and printed text remain legible on screen.
Several documents in one sitting
Add every document the form asks for together. Each PDF is compressed separately against the 100KB target, and all of them can be downloaded in one go.
Receipts and fee challans
Payment receipts, bank challans and hostel fee slips are simple layouts on white paper. They shrink to 100KB easily, which suits reimbursement claims or refund requests where each attachment must stay small.
What happens to a PDF compressed to 100KB
In Target Size mode the compressor renders each page at 1.4 times its size in points, roughly 100 pixels per inch, and encodes it as a JPEG. It then searches up to eight JPEG quality levels between 5 and 92 percent, keeping the best result that is at or under 100KB. If no quality fits at that resolution, it makes one last pass at 72 pixels per inch and the lowest quality.
The output is a new PDF with the same page dimensions, but each page is now a picture. Text can no longer be selected, searched or copied, and links, bookmarks and fillable form fields from the original are not carried over. For an upload that only needs to be viewed or printed this rarely matters; keep the original if you need an editable or searchable copy.
Page count decides whether 100KB is possible
The 100KB budget is shared by all pages. One A4 page rendered at about 100 pixels per inch is about 833×1178 pixels, close to a million pixels, and 100KB gives it a little under one bit per pixel, which keeps printed text crisp. Five pages leave about 20KB each and ten pages about 10KB each, where letters start to blur and the final low-resolution pass may still not fit.
The row for each file shows the size the compressor actually reached. If it is still above 100KB, the tool has already tried its lowest quality, so the document itself has to get smaller. Remove blank or unneeded pages with Delete Pages, split a long file into the parts the form asks for, or check whether the portal accepts each page as a separate upload.
Colour costs bytes too. A scanned page with a grey or yellowish paper tone compresses worse than clean white; converting a text document with Grayscale PDF before compressing usually leaves more of the budget for the letters themselves.
Before you upload a 100KB PDF
If you are scanning specially for the upload, choose black-and-white or greyscale in the scanner app, because the compressor keeps whatever colour the page carries. The scan's dpi matters less than you might think: every page is re-rendered at about 100 pixels per inch anyway, so a 600 dpi scan mostly makes the original bigger and does little for the 100KB result.
Open the compressed copy and zoom to 100 percent. Check that the smallest print, such as roll numbers, dates and seals, is readable, because verification staff read the same file you upload.
Watch the units. This tool counts 1KB as 1,024 bytes, so the file can be up to 102,400 bytes. A portal that counts thousands of bytes would show that as 102.4KB; if the limit is enforced to the byte, set the target to 95 instead of 100.
If the amber note “Target is at or larger than the original” appears, the PDF is already under 100KB. Upload it as it is, because rendering it again would not make it smaller and would only turn its text into images.
Frequently asked questions
Why is my PDF still larger than 100KB after compressing?
It has more pages than 100KB can hold even at the lowest quality and resolution. Delete unneeded pages, split the document, or upload the pages separately if the form allows it.
Will I still be able to select or search text in the 100KB PDF?
No. Every page is turned into an image to reach this size, so the text is only visible, not selectable. Keep your original if you need a searchable version.
Can I compress several PDFs to 100KB each at once?
Yes. Add them together and press Compress once. Each file gets its own 100KB target and its own row showing the result.
What happens to a password-protected PDF?
It is skipped and a message says how many protected files were left out. Remove the password with Unlock PDF, then add the unlocked copy here.
Is my document sent to a server to be compressed?
No. Pages are rendered and re-encoded by your own browser using pdf.js and pdf-lib, so certificates and ID proofs stay on your device.
Does a 100KB PDF print clearly?
A one-page document prints legibly for most forms, since pages are rendered at roughly 100 pixels per inch. That is below office-print quality, so fine print looks softer on paper than on screen.
Which pages work best at 100KB, scanned or digital?
Both end up as images, so what matters is content. Black text on white paper holds up well, while photographs, coloured letterheads and dark scanner shadows use up the budget quickly and look grainy.