pdfviz

Compress PDF
to 10 MB

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

10 MB is 10,485,760 bytes. It is the cap on most mail providers and on many document portals, and it is where big scanned archives usually have to land. The published bench did not measure a 10 MB target directly. The limit that bites first at this size is not compression, it is browser memory, and this page covers both.

How to compress a PDF to 10 MB

  1. Choose the PDF

    Press Choose a PDF, or drop the file on the page. The file is read in this browser tab and is not sent to any server.

  2. The target is already set

    This page opens with the target fixed at 10 MB, so there is nothing to type. Pick a different compression level if you want, or enter your own smaller number for a different size.

  3. Press Compress

    Four methods race against each other: copy the pages into a fresh file, re-encode the placed images, cut each embedded font down to the glyphs the pages draw, and only when no other method reached the target, redraw the pages as images with the text kept on top.

  4. Read the check, then download

    Every candidate is opened again and its characters are counted against the source. The page shows the size, the method that won, and the characters kept before it offers the download.

The four methods are described in full, with the measurements behind them, in how it works. The whole process runs in your browser through WebAssembly, which means your file is never uploaded and no account is needed.

The real ceiling is the browser tab, not the 10 MB target

A compressor that runs in the browser has no server to hand the work to, so all of it happens in the tab. The source has to be held in memory, and so do the candidates the four methods build while they race. A source of a few hundred megabytes can run a tab out of room before any target is decided.

The large file page covers this directly. The short version is that a desktop browser with plenty of free memory handles far more than a phone, and splitting a huge document into parts is safer than pushing one file through whole.

If a tab dies partway through, that is the memory ceiling and no setting moves it. The file was never sent anywhere, so nothing is lost except the attempt. Close other tabs, try again on a machine with more memory, or split the document first.

What kinds of documents land at 10 MB

A two hundred page scanned archive at a readable quality. A photo heavy brochure with dozens of product shots. A technical manual with hundreds of diagrams and screenshots. These are the documents where 10 MB is a genuine target rather than a formality.

The compress tool reports the size it reached and the method that won. On a scanned archive an image method usually wins, and the quality it chose is worth reading, because it tells you how much headroom was left. The tool samples pages rather than guessing, walks down from high quality, and stops at the first setting that meets the target.

Text exports behave completely differently. A forty page text document usually arrives under 10 MB before compression even starts, because text weighs very little. The weight in a PDF comes from images and embedded fonts, not from the characters on the page.

Before you compress a huge file to 10 MB

Remove what nobody will read. Duplex scanners leave blank versos, cover sheets get scanned by habit, and separator pages survive into the final file. On a two hundred page archive that can be forty pages of pure weight, removed at zero cost to anything you care about.

Then decide whether one file is the right shape at all. Ten files of twenty pages each open faster, download faster, and survive a mail limit that one 10 MB file does not. A 5 MB target per part is a better outcome than one file that only just fits.

Removing pages first also changes the arithmetic on everything after it. Each remaining page gets a larger share of the target budget, which means a higher image quality for the same final size. Use organize pages to strip blank sheets before you compress.

Real use cases for a 10 MB target

Scanned archives that have to stay in one piece for a legal submission or a regulatory filing. A two hundred page archive at roughly 50 KB per page stays readable under 10 MB.

Photo heavy brochures sent through mail systems with a 10 MB attachment ceiling. The image re-encoding method picks the quality that fits and tells you what it chose.

Technical manuals with embedded diagrams that need to stay legible. The tool samples the worst page before it picks a quality, so small print and fine lines get checked.

Questions about compressing a PDF to 10 MB

Why does my browser run out of memory on a large PDF?
Because the source and every candidate the methods build have to sit in memory at the same time. The tab has a fixed budget, and a few hundred megabytes of source plus working copies can exceed it. Splitting the file first avoids it entirely.
Is 10 MB a reasonable target for a scanned book?
For a couple of hundred pages, yes, at roughly 50 KB per page. Body text stays readable at that budget. Illustrations and small print do not fare as well, so check the worst page rather than the first one.
Does compressing to 10 MB take a long time?
Longer than a small file, because every page has to be processed and the output has to be read back and checked. The bench corpus contained nothing near this size, so allow more time for a large source.
Can I compress a 10 MB PDF on a phone?
Sometimes, and it is the least reliable place to try. A phone browser has far less memory headroom than a desktop one, and a large file is exactly the case that exhausts it. Use a computer when the source is this big.
Will the text stay selectable after compression to 10 MB?
Yes. Every candidate is re-opened and its characters are read back and compared with the source. Anything below 98% retention is refused.
How does pdfviz compare to server based compressors for large files?
Server based tools are faster on huge files because they have more memory, but they also take custody of your document. pdfviz runs entirely in your browser, so the file never leaves your machine. For sensitive archives, that trade is the point.

The other pdfviz tools

They all run in a browser tab like this one. Each reads its own output back and checks it before offering the download, and none of them needs an account.

Where to go next