The short version

Drop the PDF and press the button. The tool works in three stages, cheapest first, and stops at the first one that gets the file under 100 KB.

Images are recompressed in place first, so text, links and forms stay exactly as they were. Only when a file still will not fit are the pages rebuilt as images, and even then an invisible text layer keeps the words searchable. A file already under the cap is handed back untouched. If your file is already small enough, you do not need this tool.

The 100 KB ceiling appears on the forms where the document is a single page: an ID card, a photograph page, a signature specimen, a school-leaving certificate. On those it is achievable with room to spare. On a multi-page colour form it is achievable only by accepting a soft image, and the tool will tell you which of the two you have.

Where the 100 KB limit comes from

Who asks for itPlaces that cap uploads at 100 KB
  • Indian and South Asian government portals: ID and certificate uploads100 KB per file
  • School and university admission forms100 to 200 KB
  • State recruitment and exam portals50 to 100 KB
  • Photo and signature specimen uploadsOften 20 to 50 KB, as JPEG
  • Older municipal and utility portals100 KB, unchanged for years

Caps like this are rarely revisited once set. They are written into a portal's upload form at launch, sized for the storage and bandwidth of the day, and outlive both. The practical response is not to argue with the number but to produce a file that clears it while staying readable, which is what the ladder below does.

How the tool hits 100 KB

1

Add the PDF

Drop it or browse. It is read into browser memory; nothing is uploaded, so a slow connection makes no difference.

2

Stages one and two: tidy, then the images

Unused objects, thumbnails and stale metadata go first, which costs nothing at all. Then the pictures inside the file are recompressed in place, starting at 200 ppi, while your text, links and form fields are left exactly as they were.

3

Stage three, only when it is needed

If the images were not where the weight was, the pages are rebuilt as pictures with an invisible text layer behind them, so the words stay searchable. It probes at 150 dpi, works out the resolution that should fit, and will not go below 60 dpi.

4

Download, and read the result line

It shows the final size and which stage produced it. If none fitted, you still get the smallest attempt, labelled honestly, rather than a file that silently missed the target.

The image ladderSeven rungs, from 200 ppi down to 60
200q82150q75120q66100q5880q5072q4260q36Rung 1: images barely touched (ppi above, JPEG quality below)Rung 7: visibly softYour text, links and form fields are untouched at every rung
Stage two walks down this ladder, recompressing the pictures inside the file and leaving everything else alone. It stops at the first rung under 100 KB, and abandons the ladder early when the images are not what is making the file big.
Stages
Three

Structure, then the images in place, then the pages as pictures. It stops at the first stage that fits.

Text after compression
Kept

Untouched at the first two stages. If the pages do get rebuilt, an invisible text layer keeps them searchable.

Bytes uploaded
0

The IDs, forms and statements people compress for portals never leave the device.

What fits in 100 KB, and what does not

The honest answer depends on page count and on what is on the pages. Text pages are cheap because a rendered page of black text compresses extremely well as a JPEG. Colour scans and photographs are expensive because every pixel carries information the encoder has to keep. The estimator uses typical figures to show which attempt your file is likely to land on.

Try it

Will your file fit in 100 KB?

Enter the page count and what the pages contain. The estimate shows the attempt that is likely to succeed and what that attempt looks like.

Typical sizesCommon documents against the 100 KB line
1-page text documentabout 55 KB2-page text documentabout 95 KB1-page colour ID scanabout 250 KB3-page colour scanabout 730 KB100 KB
Estimates before any quality is traded away. Anything past the line has to go down the image ladder, and the last two usually need the pages rebuilt.

When it cannot reach 100 KB

Some documents will not fit legibly, and the tool says so rather than pretending. When the result line reports a miss, three moves usually solve it:

  • Split first. Use Split PDF to break the file into parts and compress each. Most portals accept several attachments even when each one is capped at 100 KB.
  • Rescan the source. A fresh 150 dpi greyscale scan compresses far better than a colour scan that has already been through one compressor. Every pass costs quality, and the first pass should start from the cleanest source.
  • Check the real limit. Portals sometimes state one number and accept another. Read the fine print, or try a slightly larger file before compressing harder than you need to.
One pass, from the original
Compressing an already-compressed file compounds the quality loss without much further saving. If the first result is not right, run the original again rather than the output. And keep the original: the compressed copy is for the portal, not for your records.

Getting a single ID page under 100 KB cleanly

Most 100 KB uploads are one page, and one page is where preparation pays. The tool can only work with the pixels it is given, so a smaller, cleaner starting image reaches the cap at a higher rung of the ladder.

  • Crop to the card. A phone photo of an ID card on a desk is mostly desk. Crop to the card before making the PDF, and the same 100 KB buys three times the detail.
  • Greyscale beats colour. Unless the portal insists on colour, a greyscale scan at 150 dpi is sharper at 100 KB than a colour scan at any setting.
  • One page per file. If the portal has separate slots for front and back, use them. Two single-page files at 100 KB each carry twice the detail of one two-page file.
  • Start from the original. A screenshot of a scan, or a scan that has been through WhatsApp, has already lost detail. Go back to the first copy.
Photo and signature slots want a JPEG, not a PDF
Many of the same portals ask for a passport photo or a signature as an image file at 20 to 50 KB. That is a different job: export the image at a small pixel size and moderate JPEG quality from any photo app. This tool produces PDFs, and a PDF wrapper around a tiny image is wasted bytes.

Where people use the 100 KB target

Typical jobsWhat gets compressed to this size
  • Aadhaar, PAN and driving licence uploads1 page, fits
  • School-leaving and degree certificates1 to 2 pages, fits
  • Signature specimen pages1 page, fits easily
  • Short declarations and affidavits1 to 3 pages, usually fits

Why this runs in your browser

The files people compress for portals are the ones that identify them: passports, ID cards, certificates, bank statements, tax forms. Uploading them to a compression website in order to upload them again to the portal doubles the exposure for no benefit.

Two ways to compressOne of them never transmits the document
Your devicePDFin memoryBrowser enginecompressDownload0 bytes leavethe machineTypical online toolPDFon diskuploadServercopies filedownloadA full copy now sits on hardware you do notcontrol, under a policy you cannot audit
PDF.js renders the pages and pdf-lib rebuilds the file inside the tab. The document is read into memory, compressed there, and offered as a download.

The tool is right above

Everything on this page runs in your browser. Scroll up, drop the file, and keep it on your machine.

Jump to the tool

Common questions

The questions people have with a 100 KB cap in front of them.

01Can any PDF fit in 100 KB?

A one-page ID scan or a two-page text document, yes, usually at the first or second attempt. A ten-page colour scan cannot while staying legible. Split it and upload the parts if the portal allows, or ask whether the stated limit is really per file.

02Which portals ask for 100 KB?

Mostly Indian and South Asian government and admissions portals, for ID documents, certificates and declarations. The number dates from when server storage was expensive and has rarely been revisited.

03Will the text still be readable?

For text documents, yes, and usually at the first attempt. For colour scans and photo-heavy pages, later attempts soften the image visibly. The result line tells you which attempt produced the file, and the estimator above predicts it.

04Will the text still be selectable?

Usually, yes. The first two stages leave the text exactly as it was. If the file only fits by rebuilding the pages as pictures, an invisible text layer goes behind them so the words can still be searched and copied.

05What if the file cannot get under 100 KB?

You still get the smallest attempt, with the result line stating the final size honestly. Split the file into parts, or rescan the source in greyscale at a lower resolution, and try again.

06My file was already small. Why did it grow?

The tool checks the size first and hands a file that already fits straight back, untouched. If the file is already under the cap, send it as it is.

07Are my files uploaded anywhere?

No. Rendering and compression run in your browser. The file never leaves the device.

08Is it free?

Free. Every tool, unlimited use, no signup.