Compress PDF Files
Reduce a PDF's file size right in your browser. Each page is optimised on your device, so scans and photo-heavy documents can shrink dramatically without the file ever being uploaded.
Drag and drop a PDF here, or
Up to 100 MB. The file is compressed locally and never uploaded.
Pages are flattened into images, so text stops being selectable and links are removed. That is what makes scanned PDFs shrink so much — keep the original if you need searchable text or a signature to stay valid.
How this PDF compression works
The tool renders every page at the resolution you choose and re-encodes it as a JPEG, then rebuilds the PDF around those images. It is the same strategy scanning software uses, and it is why the savings on photo-heavy documents can be dramatic: a 300 DPI scan stored as a lossless image can shrink by 80–90% at 120 DPI with no visible difference on a screen. The physical page size is preserved, so the compressed file prints at the same dimensions as the original.
When raster compression is the right tool
Use it for scanned contracts, receipts, ID copies, brochures, and any PDF that is really a stack of photos. Those files carry enormous image data that can be reduced aggressively without anyone noticing. It is also the fastest way to get an email attachment under a size limit: start at Balanced and step down to Strong if the mail server still complains. The PDF to JPG converter does the same rendering if you need the pages as separate images instead.
When to keep the original instead
Text-only and vector PDFs — invoices generated by software, forms, reports with charts — are already stored efficiently, often a few kilobytes per page. Turning those into images can make the file larger, and it always costs you selectable text, search, and links. If your goal is a smaller text PDF, exporting a fresh copy from the app that created it (or printing to PDF with "reduce file size") usually beats any converter. This tool detects the larger-result case and keeps your original rather than handing you a worse file.
Choosing a compression level
Light keeps 150 DPI at 85% quality — safe for documents that will be zoomed or printed. Balanced, the default, renders at 120 DPI and 75%, which looks clean on any screen. Strong drops to 96 DPI at 60% for attachments, and Extreme goes to 72 DPI at 45% when a hard size cap leaves no choice. Once compressed, the split and merge tools can reorganise the result, and rotation fixes a sideways scan.
Frequently asked questions
How do I compress a PDF without uploading it?
Drop the PDF onto the box above, pick a compression level, and click compress. Each page is rendered and re-encoded on your device, the smaller PDF is assembled in memory, and you download it directly — the document is never uploaded, which matters for contracts, statements, and scans of IDs.
Why does compressing flatten the text?
This tool compresses the way scan software does: each page is converted to an optimised image, which is where the big savings come from on photo-heavy and scanned documents. The trade-off is that text stops being selectable or searchable and links are removed. If you need searchable text, keep the original — most text-only PDFs are already compact.
Which compression level should I choose?
Balanced (120 DPI, 75% quality) is the right default: pages stay sharp on screen and file sizes drop substantially. Light (150 DPI, 85%) is for documents that will be zoomed or printed. Strong (96 DPI, 60%) is for email attachments and previews. Extreme (72 DPI, 45%) is a last resort for a size cap, and small text will soften.
Why did my PDF get bigger instead of smaller?
Vector and text-only PDFs are already stored very efficiently — a page of text can weigh a few kilobytes — so converting it to an image can add size rather than remove it. When that happens, this tool keeps the original file and tells you, so you never download a worse result.
Does compressing break a digital signature?
Yes. Flattening a page changes its content, so an existing signature will no longer validate. Keep the signed original if it needs to stay verifiable, and compress a copy only for sharing or archiving.
Can I compress a password-protected PDF?
No — encrypted PDFs cannot be decrypted in the browser, so the tool rejects them with a clear message instead of producing a file that will not open. Remove the password first, then compress the unlocked copy.
Related reading
- Why Scanned PDFs Compress Differently from Text PDFs
One PDF shrinks by 90%, another gets bigger. The difference is whether the pages are pixels or vectors — and it changes what you should do.