PDFGym
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Compress PDF
to 300 KB

or drop one here
Compression level
Target size
Choose a PDF file first.

A 300 KB cap, or 307,200 bytes, is the classic budget for one scanned page: a certificate, an identity page, a signed form. This page shapes your PDF to that number entirely in the browser, checks the result by reopening it, and never uploads the file anywhere.

Getting to 300 KB in four steps

  1. Open your PDF here

    Press Choose a PDF or drag the file onto the page. It loads into this tab on your device; identity documents deserve that privacy.

  2. Leave the preset alone

    300 KB is already filled in on this page. If your box wants a different number, tap a preset chip or type the exact cap into the KB field.

  3. Press Compress

    The four methods race locally: structural rebuild, image re-encoding, font subsetting, and the full page redraw held back for files nothing else could shrink.

  4. Inspect, then download

    You get the final size, the saving and the original size next to a preview. Press Download PDF when seals and small print read cleanly; the file keeps its name plus -compressed.

Curious what the engine rewrites inside? How it works has the tour. When boxes keep bouncing you, the size reduction guide maps caps to settings.

The licence renewal with a Friday deadline

Petra, a freelance electrician, must renew her trade licence online by Friday. The renewal portal accepts one PDF per proof, capped at 300 KB each. Her safety certificate scan, certificate-safety.pdf, is 2 pages at 3.4 MB: two phone photos saved at full resolution inside a PDF wrapper.

She opens this page, the 300 KB target is already set, and one press later the file sits at 265 KB. The embossed seal stays legible in the preview, the text stays selectable, and the upload passes on the first attempt. Total time: under two minutes, with the certificate never leaving her laptop.

Single page proofs are the happiest customers of this number. The whole 300 KB budget serves one or two pages, so print stays sharp and stamps stay readable without any heroics.

Count pages before you count kilobytes

This target divides brutally. One page gets all 300 KB and looks pristine. Four pages get 75 KB each and still hold printed text. Twenty pages get 15 KB each, and fine print turns to mush. The file does not know your box count; it only knows the budget per page.

So when a four page scan must fit, this page is the whole answer. When a twenty page scan must fit, the answer is surgery first: split the scan into one file per proof and upload the parts, or cut the pages the box never asked for. Each surviving page then eats from a full plate instead of crumbs.

Close neighbours: 200 KB for stricter boxes, 400 KB when you may spend extra. If a box already refused you once, aim at 290 KB rather than the full number; portals that count flat thousands are tighter than their label.

Misses at 300 KB and their fixes

Landing above the number with scans usually means too many pages or poster sized photos. Shrink the page count first, then the bytes. A result that hits the number but looks soft means the per page budget ran thin: fewer pages per run, or accept a bigger file and ask the recipient whether a second upload slot exists.

Text exports that barely move are a different story: they were already lean, or they are locked. A PDF that demands a password on open skips the rebuild tricks, so clear it through Unlock PDF and compress the open copy. Never recompress an already squeezed file; the second pass re-encodes the images and softness stacks.

Better routes than a tighter squeeze

When the portal takes one file per document, separate uploads at comfortable sizes beat a single starved bundle every time. When the recipient only needs to see the page in chat, PDF to JPG exports the pages as pictures with no document wrapper. And when the box is simply unreasonable for the proof it demands, a polite note to the helpdesk, naming the cap and the page count, resolves more cases than any slider.

Brief answers on the 300 KB target

Is 300 KB enough for a certificate with a seal?
For one or two pages, yes. Seals, stamps and signatures stay legible at this budget. Check the seal at full zoom in the preview before sending.
Why do so many portals pick exactly 300 KB?
It matches one readable scanned page, which is what most proof boxes were designed around. The number is about per applicant storage, so it rarely grows even as phone cameras do.
Will my scanned handwriting survive 300 KB?
On one or two pages, usually. Handwriting softens first when budgets thin, so give short files the full number and read the smallest line in the preview.
Do I upload my ID document to use this?
No. Everything runs in your browser tab; the file is read from disk, processed in memory and saved back to downloads. No server ever sees it.
Can any PDF reach 300 KB?
No honest tool promises that. Long photo heavy files may need splitting or a roomier cap; the result tells you exactly where the run landed, and Details names what won.

Tools that pair well with small proofs

Cut, split, convert or inspect before and after the squeeze. They all run locally in the tab, with no account and a recheck before download.