Compress PDF

Add one or more PDFs, pick how hard to squeeze, and press Compress. Each file shows its size before and after, how many of its images were recompressed, and a download button; with several files there is a total and a ZIP of everything.

Compression runs entirely in your browser. Most "compress PDF" sites upload your document to their servers to do this; here the file never leaves your device, which matters for contracts, payslips, medical records, and anything else you would rather not hand to a stranger's server.

What actually makes a PDF big

In almost every oversized PDF, the weight is images: scanned pages, phone photos, and screenshots stored at far more resolution than the page needs. A 12-megapixel photo placed 4 inches wide on a page carries roughly 750 pixels per inch — five times what a screen or an office printer can show.

So that is what this tool works on. For every image it finds:

• It works out how large the image is actually drawn on the page, by following the page's drawing instructions, and scales it down to the target resolution for that size. An image used at several sizes keeps enough pixels for the largest.
• It re-encodes JPEG photos at the chosen quality.
• On Balanced and Smallest it also converts large losslessly stored images — common in scans — to JPEG.
• It only swaps an image when the new one is smaller, and leaves anything it can't reproduce faithfully alone: CMYK and other print colour spaces, masks, and images with special decoding.

On top of that, it deflates any streams stored uncompressed and saves the file with compressed object streams, which trims the overhead of the many small objects inside every PDF. If none of this makes the file smaller, it tells you so instead of handing back a bigger copy.

Choosing a level

• High quality — 200 dpi, 85% JPEG, lossless images untouched. Safe for printing; still shrinks most phone-photo PDFs dramatically.
• Balanced — 150 dpi, 75% JPEG. Sharp on any screen and fine for an office printer: the right choice for email attachments and upload portals.
• Smallest — 100 dpi, 60% JPEG. For on-screen reading when the size limit is what matters most.
• Custom — set the resolution (72–300 dpi), the JPEG quality, and whether lossless images may become JPEGs.

What it can't do

Being honest about this saves you time. Browser-side compression can only shrink what it can re-encode, so:

• Text-only and vector PDFs barely change. A PDF exported from Word or a design tool with few images is usually already compact; its size is fonts and drawing commands, which this tool doesn't rewrite.
• Fonts are left as they are. Desktop software such as Acrobat can strip unused glyphs from embedded fonts; this tool doesn't, so a small PDF with several large embedded fonts stays roughly the same size.
• Already-optimized files won't shrink further. If the images are already at screen resolution, there is little left to remove.
• Password-protected PDFs must be unlocked first.

Example

lease-signed.pdf — 9 pages scanned with a phone, 14.2 MB
9 JPEG page images, 3024×4032 each, drawn at A4
Compression: Balanced

lease-signed-compressed.pdf — 1.6 MB (−89%)
9 of 9 images recompressed
Each page image now 1240×1754 (150 dpi at A4)

Text on the scanned pages stays crisp at 150 dpi; the reduction comes almost entirely from the excess resolution.

Common uses

• Get a scanned document under an email attachment limit (often 10–25 MB) or an upload portal's limit
• Shrink a photo-heavy report or catalog before sharing it
• Reduce a batch of PDFs at once before archiving them

How do I compress a PDF without uploading it?

Add the PDF above, choose Balanced, and press Compress. The compression runs in your browser with JavaScript, so the document never leaves your device — no upload, no account, and no watermark — and you can download the smaller copy right away.

Why didn't my PDF get much smaller?

Most of a PDF's size is usually images, and that is what this tool shrinks. A PDF that is mostly text, vector graphics, or embedded fonts — a document exported from Word, for example — is already compact, and its fonts and drawing commands are left as they are. If no smaller version is possible, the tool says so rather than giving you a bigger file.

How do I compress a PDF to under 1 MB (or another size limit)?

Try Balanced first, then Smallest. If it is still too big, choose Custom and lower the resolution towards 72–96 dpi and the JPEG quality towards 50%. Splitting the document into parts with the PDF Splitter is the other option when a portal has a strict per-file limit.

Does compressing a PDF reduce the quality?

Only the images change, and only when the new version is smaller. Text and vector graphics stay exactly as sharp as before. At Balanced (150 dpi) images remain sharp on screens and fine for office printing; choose High quality for documents you will print professionally.

Is the text in my PDF still selectable and searchable afterwards?

Yes. Only the images are re-encoded; text, links, bookmarks, and form fields are carried over untouched, so text stays selectable and searchable — exactly as it was in the original.

Can I compress several PDFs at once?

Yes. Add as many PDFs as you like; they are compressed one after another with the same settings. Each gets its own download button, the tool shows the combined size before and after, and Download all bundles the smaller files into one ZIP.

Why can't this compress as much as Adobe Acrobat?

Desktop software can also subset embedded fonts, strip unused objects more aggressively, and re-encode print colour spaces such as CMYK. In a browser, this tool sticks to changes it can make safely: downsampling and recompressing RGB and grey images and compressing the file structure. For image-heavy PDFs, which is most large PDFs, that is where nearly all the savings are anyway.