🗜 PDF300

Compress a PDF

A file that is too big to email, or over an upload limit. PDF300 has two ways to make it smaller, and you pick the trade-off.

Open the tool

How it works

Add the PDFDrop the file onto the page. Nothing is sent anywhere in browser mode.
Choose how hard to squeezeLighter settings keep the pages sharper; harder settings make a smaller file.
DownloadSave the smaller file. The original on your device is untouched.

Questions

Why are there two compress tools?

The browser tool re-encodes the pages as images — fast, private, and good enough for scans. The server tool keeps text sharp and usually makes a smaller file, but the file has to be sent to the server for that.

Can I hit an exact size, like 2 MB?

Yes — that is what the Target size page is for. It tries settings until the file lands under the size you name.

Guide: doing it well

When you need to compress a PDF

Most people meet this problem at the last step of something else: an email that bounces because the attachment is over 20 or 25 MB, a job portal that refuses anything above 2 MB, a government form that stops at 300 KB or 500 KB. The document itself is fine — it is just carrying more data than the page needs. That extra weight is nearly always images: scanned pages, phone photos, or pictures pasted into a Word file at full camera resolution.

Two ways to compress, and how to choose

Browser compression (the Compress tool) draws every page as a JPG and builds a new PDF from those pictures. It runs on your own computer, so nothing is uploaded. The four levels set two numbers: the widest a page can be in pixels, and the JPG quality. Low is 1600 px at quality 85, Medium 1280 px at 72, High 1024 px at 60, and Extreme 800 px at 45. You can also type your own values.

The trade-off is that the result is image-only. Text can no longer be selected or searched, and a screen reader cannot read it. For a scan that was already a picture, you lose nothing. For a text document exported from Word, you lose the text layer.

Server compression (High-quality compress) sends the file to our server, where Ghostscript rewrites it with its "ebook" preset: images are resampled to about 150 dpi, while text and vector drawings stay as they are. Text stays sharp and searchable. This is usually the better choice for reports, CVs and anything with small print.

Step by step

Look at what is heavy.A 40-page text PDF of 8 MB almost certainly contains a few huge images. A 3-page scan of 8 MB is simply scanned at too high a resolution.
Try the gentlest setting first.Start with Low or Medium. Open the result and zoom to 100 % on the page with the smallest print.
Step down only if you must.If the file is still too big, go one level harder rather than jumping to Extreme.
Need an exact number?Use Compress to target size, which searches for the sharpest version that fits under the limit you type.

Keeping it readable

Small print is what breaks first. A page 1024 px wide is roughly 120 dpi on A4 — fine for body text, marginal for footnotes and stamps. If an official seal or a signature has to stay legible, check it specifically before you submit. Grey-and-white documents compress much better than colour ones; if your scanner has a greyscale mode, rescanning in greyscale often does more than any compression setting.

Privacy

Browser compression never uploads the file; the work happens in this tab using pdf.js and pdf-lib. High-quality compression does upload it. On the server the file is processed in a temporary folder that is deleted as soon as the response is sent, and we do not keep a copy.

Common problems

The file got bigger. This happens with PDFs that were already efficient text files. Re-drawing text as pictures adds weight. Use server compression instead, or leave the file as it is.

The output is blurry. Raise the max width or the JPG quality one notch. Blur at 800 px is expected.

The browser tab froze. Very long scans use a lot of memory. Split the file into parts with Split, compress each part, then merge them back.