Compress PDF (Free, No Upload — Reduce PDF File Size)

A free tool that compresses PDF files. Just drag and drop, and it shrinks your document to fit email attachment limits or web form upload caps. Everything runs inside your browser and no file is ever sent to a server, so you can safely compress confidential quotes, contracts and CVs.

Choosing a compression level

Level	Settings	Best for
Strong	96 dpi / JPEG 50	Documents that only need to be readable on screen. Useful for web forms with tight file size limits.
Balanced	120 dpi / JPEG 72	The standard choice for email. An A4 document stays comfortably readable while the file shrinks substantially.
High quality	150 dpi / JPEG 85	Documents you may print. The saving is smaller, but fine text and thin drawing lines hold up better.

How much different PDFs shrink

Type of PDF	Effect	Why
Scanned documents	Very large	Office scanners store pages as high-resolution images, so simply lowering the resolution often cuts the file to a fraction of its size.
Photo-heavy files	Large	A single phone photo is several megabytes. Bringing it down to display resolution makes a big difference.
Presentations	Moderate	The more charts and images, the better it works. Slides that are mostly text see limited benefit.
Text-only documents	Small or counterproductive	They are already small as text data, so converting to images can make them bigger. If that happens, stay with the original.

Text in the compressed PDF can no longer be selected or searched. This tool reduces size by redrawing every page as an image, so the text layer is not preserved. If you need to search the wording of a contract or edit the file later, keep your original as well.

What PDF compression does

Compressing a PDF means shrinking the file size while keeping the document looking the same. It is the usual fix when a file exceeds an email attachment limit — often around 10 MB in corporate systems — or the upload cap on a government or client web form. Scanned documents are the common culprit: a single page from an office scanner can easily run to several megabytes, which makes sending them impossible without help.

This tool redraws each page at a resolution you choose and re-embeds it as a JPEG. Everything happens inside your own browser, so no file is ever sent to a server. Most online PDF compressors upload your document first; here you can safely process quotes, contracts and CVs that should never leave your machine.

How to compress a PDF

Choose your PDF Drag it onto the drop zone or click to browse. Several PDFs can be processed in one go.
Pick a level Balanced is enough for email. Choose Strong when the size limit is tight, or High quality if you plan to print the document.
Check the reduction The before and after sizes are shown along with the percentage saved. If it is not enough, try one step stronger.
Download the result Press "Download compressed PDF" and the file is saved with "-compressed" appended to its original name.

Tips for getting more out of it

Start with Balanced. An A4 document is perfectly readable at 120 dpi. Only step up to Strong when that is still not small enough, and you avoid throwing away more quality than you need to.
Deleting unnecessary pages first saves more than any compression setting. You can reorder and remove pages with our PDF page organizer.
If you are building a PDF from photos, shrink the images first. Resize them to around 2000 px on the long edge with our image resizer, then use image to PDF to produce a light file from the start.
The compressed PDF loses its searchable text. For contracts you may need to search in full, keep the original alongside the compressed copy.
Text-only documents are usually just tens of kilobytes to begin with, so there is rarely any point compressing them. If the size goes up, simply keep the original.

When PDF compression helps

Your email attachment is too large

The classic fix when a message bounces back as "attachment too large". Against a 10 MB cap, a scanned document will often come down to 1–3 MB.

Submitting to an official web form

Grant applications and client intake systems often cap uploads at 5 MB per file. Compression lets you meet the limit without cutting content.

Archiving scanned contracts

Scanners save at high resolution, so an archive fills up storage quickly. Compressing before filing keeps the collection manageable.

Publishing documents on a website

Heavy PDFs are slow to open and drive visitors away. Compressing before upload means mobile readers are not left waiting.

PDF compression terms

dpi: Dots per inch, the unit of resolution. Higher numbers mean more detail, and a correspondingly larger file.
Rasterisation: Converting coordinate-based content such as text and shapes into a grid of pixels. This is the method this tool uses to reduce size.
JPEG quality: A 0–100 value controlling how hard JPEG compresses. Lower values give smaller files but introduce noise around edges.
Text PDF: A PDF where characters are stored as text data. It can be selected, searched and copied, and is small to begin with.
Scanned PDF: A PDF produced by scanning paper, where each page is an image. It looks like text but cannot be searched, and takes far more space.
OCR: Optical character recognition: technology that reads characters out of an image and turns them into text data, used to make scanned PDFs searchable.

Frequently asked questions

It is never even uploaded. Reading and compressing both happen inside your browser, and the contents of the file never travel across the network. That makes the tool safe for confidential documents.

It depends entirely on what is inside. A document scanned on an office machine commonly comes down to 10–30% of its original size at the balanced setting. A PDF built purely from text is already small, so it may barely change, or even grow.

Because the tool redraws each page as an image, so the characters become picture rather than text data. That is the trade-off for a reduction that works reliably inside the browser. Keep your original if searchability matters.

A PDF that needs a password to open cannot be read. Please remove the password first. Files that only restrict printing or editing can often still be processed.

Yes, but every page is redrawn individually, so the time scales with the page count. A few hundred pages can take several minutes — please leave the tab open while it works.

Side Note — why PDFs get so heavy

Adobe released the PDF format in 1993 with one priority above all others: a document should look identical wherever it is opened. To guarantee that, the file can carry the shapes of the letters themselves — the embedded fonts — so the layout holds even if the recipient has none of those typefaces installed. That thoroughness is exactly why the format became trusted, and also exactly why files balloon: a PDF can absorb anything it needs.

Scanned images are the main offender. Office machines often default to 300 or 600 dpi, and a single A4 page scanned at 600 dpi comes to roughly 35 megapixels. Given that a phone camera sits around 20 megapixels, one page of paperwork is carrying more image data than a photograph. Reading on screen needs perhaps 100 dpi, so most of that data simply occupies space without ever being used.

What is charming about the format is that a PDF page is not stored as a picture but as a set of drawing instructions: draw a line here, place this glyph at that position. Because of this, text-only PDFs can be astonishingly small — a contract running to dozens of pages may fit in a few tens of kilobytes. The flip side is that replacing those instructions with a single photograph of the page is precisely the rasterisation this tool performs.

PDF has in fact been friendly with compression from the start. Internally, elements have long been packed with Flate, the same method as ZIP, while images use JPEG or JPEG 2000 and black-and-white scans use CCITT G4, the scheme borrowed from fax machines. In other words, an uncompressed PDF barely exists; what we casually call "compressing a PDF" is really the work of revisiting the resolution and quality of what is inside and packing it again.

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