压缩 PDF

Compress PDF files without sending them anywhere

This tool helps you compress PDF documents that are too heavy to email or upload. It works on the parts of a PDF that are actually big: the photos, scans and screenshots embedded in the pages. Each one is scaled down to a sensible size and stored as a smaller JPEG, while text, fonts and vector drawings are left exactly as they were.

Because the work happens in your browser, a 40 MB scan doesn't need to travel to a server and back. You get the result as fast as your computer can process it, and the document never leaves your hands.

How to compress a PDF

It takes four steps, and most files finish in a few seconds.

1. 1

   上传 PDF

   将 PDF 拖放到上传区域或浏览选择。接受最大 250 MB 和 100 页的文件。

2. 2

   选择质量预设

   屏幕用于最小文件，eBook 为均衡默认，打印/印前用于保持较高图像分辨率。

3. 3

   压缩 PDF

   点击“压缩 PDF”。压缩在浏览器中进行，因此超大文档在较慢的设备上可能需要稍长时间。

4. 4

   下载更小的文件

   处理完成后即可下载压缩后的 PDF。

What the four presets do

Each preset sets two limits for the pictures inside your PDF: the longest edge in pixels and the JPEG quality used to save them.

If an image would come out bigger than it already is, the original is kept. And if nothing in the file gets smaller, you get your original PDF back rather than a pointless copy.

Compress PDF to 1MB, 500KB, 300KB, 200KB, 100KB or 50KB

Job portals, university admissions and government sites often cap PDF uploads at a fixed size. In India, 200 KB, 300 KB and 500 KB limits are common for certificates and mark sheets. How close you can get depends on how many pages you have and how much of each page is a scanned image.

The rebuild method for very small limits

When a preset can't reach the number you need, rebuild the document from lighter page images:

• Turn each page into an image with PDF to JPG at 72 or 150 DPI.
• Shrink the images with Compress Image, using a target size per page (for a 200 KB, two-page PDF, aim for about 90 KB each).
• Put them back together with JPG to PDF. The JPEGs are placed into the PDF as they are, so the final size is close to the sum of the images.

The trade-off is that the pages become pictures, so the text can no longer be selected or searched. For certificates and ID scans that's rarely a problem.

Why some PDFs shrink a lot and others don't

• Scanned documents are a stack of full-page photos. They often drop by 70–90%, because scanners save pages at high resolution.
• PDFs with photos, such as brochures, menus and property listings, usually shrink by half or more.
• Text-only PDFs from Word or Google Docs are mostly fonts and text. They're already compact, so expect little or no change.
• Already compressed PDFs have little left to give. Compressing the same file twice rarely helps.
• Phone camera scans from apps that save each page as a 12-megapixel photo are the best candidates of all. The Screen and eBook presets bring those pages down to a size that still reads comfortably on any screen.

Get a smaller file before you even compress

A few habits upstream save more space than any preset:

• Scan at 150 or 200 DPI, not 600. For on-screen reading and most upload forms, 600 DPI only multiplies the file size.
• Scan in grayscale when color doesn't matter. Bank statements and printed letters look the same and take less room.
• Export instead of printing to PDF. In Word, Google Docs or LibreOffice, use Save as PDF or Export. Printing to a virtual PDF printer often embeds pages as large images.
• Remove pages you don't need before uploading. Dropping a blank back page from a scan cuts the size of a two-page file nearly in half.

Limits and privacy

You can compress PDF files of up to 250 MB and 100 pages. Password-protected files need their password removed first. Links, bookmarks and form fields usually survive because the document structure is kept, but always open the result before sending something important.

Nothing is uploaded. The PDF is read, rewritten and handed back to you inside your browser tab, with no account, no watermark and no copy kept anywhere. Need to combine files after compressing? Use Merge PDF.