Compress PDF to 100 KB

What fits in 100 KB

At 100 KB the arithmetic is unforgiving. Measured with this tool, a dense A4 page of scanned text costs about 66–74 KB at 72 dpi and 115–146 KB at 100 dpi (JPG quality 72). So one page fits comfortably, two pages fit at around 70 dpi, and anything past three pages has to drop below 50 dpi, where small print turns to grey blur. A PDF exported straight from Word or Google Docs is different: our six-page text export was only 42 KB, because it stores letters, not pictures — leave such files alone.

Measured on 16 October 2026 with this tool in browser mode on our own test PDFs (synthetic A4 scans with paper noise, which is harder to compress than a clean office scan). Your numbers will differ; cleaner scans get higher resolution. “q” is the JPG quality the tool settled on. Readability labels are a rough guide: 100 dpi and up is clear on screen, 70–100 dpi keeps normal-size text readable, below 50 dpi only large text survives.

Where you will see a 100 KB limit

Limits this small are mostly found on application portals that store many files per person. We have not found an official page we could verify that sets exactly 100 KB for PDFs, so check the notice for your form. Two verified reference points:

• India's customs e-SANCHIT procedure asks for scans of no more than 75 KB per A4 page, at not less than 200 dpi in black and white (step-by-step procedure, Jawaharlal Nehru Custom House). That is a useful real-world benchmark: one black-and-white page under 100 KB is realistic.
• Recruitment notices often set separate, smaller limits for photographs (for example 20–50 KB) and signatures (10–20 KB) than for documents — see the SPUP Rajasthan 2022 upload guidelines. Do not confuse them: this page is for PDF documents.

If it won’t go below 100 KB, try this

1. Upload one page per field.If the form has separate boxes for each certificate, split the file with Split PDF and compress each page on its own. One page at 100 KB looks far better than four.
2. Crop the white margins.Empty paper still costs bytes. Crop PDF first, then compress.
3. Tick “Black & white”.For a text document, colour carries no information. It saves the most on scans with coloured paper or stamps.
4. Rescan instead of recompressing a phone photo.Shadows and paper texture are expensive. A flat, evenly lit scan compresses much better.

Questions