Compress a PDF to 100KB

Two very different documents wear the same extension

A PDF of text is a set of instructions for drawing letters, and it is already small — twenty pages might be 200KB before anything is done to it. A scanned PDF is twenty photographs of paper, and at 300 DPI in colour that is routinely 25 megabytes. They need opposite treatment, and a tool that applies one method to both gets it wrong half the time.

BriskFile checks which it has before doing anything, by measuring how much extractable text each page carries. That decision is shown to you rather than made silently.

Lossless first, always

Restructuring rewrites the file's internals — shared object streams, no duplicated resources, metadata dropped — without redrawing a single page. Text stays selectable, quality is untouched, and on a bloated export it can remove a quarter of the file for nothing.

It is often not enough for 100KB, which is a genuinely tight budget for a document of any length. Where it is not, the pages are rendered and the resolution searched — and that is a real trade, because the text stops being text.

The search measures one page, not the whole document

Rendering an entire document to test a setting costs about three seconds, so trying five settings that way would take half a minute — and considerably longer on a phone. Instead a single page is rendered and multiplied by the page count, which predicted the finished file to within one percent at every setting measured, and costs about half a second a go.

The resolution is then solved rather than searched: page size tracks pixel count, so the right resolution follows arithmetically from one measurement. Resolution is always traded before quality, because fewer pixels are far less visible than compression artefacts on what is already an image of text.

When it cannot be done

Some documents will not fit. A long, dense scan cannot reach 100KB at any resolution worth using, and the honest answer is to say so rather than return something unreadable or something over the limit. Splitting it into fewer pages is usually what the form actually needs — the splitter is here.

Questions

How do I get a PDF under 100KB?

Restructuring the file first, and rendering the pages only if that is not enough. BriskFile tries the lossless route — rewriting the file's internals, dropping duplicated resources and metadata — because that keeps the text selectable. If the result is still over 100KB, it renders the pages as images and searches for the resolution that fits.

Will the text still be selectable afterwards?

If restructuring alone got it under the limit, yes, and nothing about the document changed. If the file had to be rendered to reach the target, no — the pages become images, and that is an unavoidable consequence of the size you asked for rather than a choice made carelessly. The tool tells you which happened.

Why is a scan so much larger than a text document?

Because a scanned page is a photograph of a page. A 20-page text document might be 200KB; the same 20 pages scanned at 300 DPI in colour is routinely 25MB. Scans are where a size target is both most needed and most achievable, since the resolution is nearly always far higher than anything needs.

What if my document cannot reach 100KB?

It says so plainly rather than handing back something over the limit. A long, dense scan may not fit in 100KB at any resolution worth using — splitting it into fewer pages is usually the answer, and there is a splitter for that.

How long does it take?

A couple of seconds for a short document. Rather than re-rendering the whole file for every attempt, BriskFile measures a single page and multiplies — a probe costs about half a second where a full pass costs three, so the search finishes in about the time one naive attempt would take.

Is my document uploaded?

No. Everything happens in this page. The documents people put through a size limit are applications, certificates, statements and identity papers, which is precisely the category worth not sending to an unknown server.

What BriskFile will not do to you

• Your files never leave your device

  Every conversion runs in your browser. Open DevTools, watch the Network tab, and you will see no upload — because there is not one.

• No account, no email, no watermark

  Nothing to sign up for and nothing stamped on your images. There is no step between choosing a file and getting it back.

• No limits at the download button

  No daily cap, no file counter, no "upgrade to download". If the tool starts a job, it finishes it.

• Checkable, not just claimed

  Open the Network tab and convert something — nothing goes out. Or load the page, disconnect, and watch it keep working: the tool is already on your machine, and your file never leaves it.