All Converter Pro
压缩 PDF 文件
在线免费压缩 PDF 文件。选择质量级别,缩小文件以便通过邮件和上传门户发送,并保持文档可读。无需注册。
关于此 压缩 PDF 工具
Compress PDF reduces large PDF files by optimizing images, fonts and structure. Use balanced compression for normal documents, high quality for printable files, or maximum/extreme compression when you need the smallest possible file, for example to fit an email attachment limit. The result shows the original and compressed file sizes so you can see exactly how much space was saved.
如何使用 压缩 PDF
- 打开工具并添加您的文件、文字或数值。
- 检查可用选项,例如页面范围、输出格式、质量、密码或语言。
- 开始处理,并在完成前保持浏览器窗口打开。
- 下载结果,如有需要可继续使用相关工具。
实用提示
- 对于扫描的 PDF,支持 OCR 的工具会尽可能自动运行文字识别。
- 对于大文件,在通过邮件分享或上传到门户网站之前,请使用压缩工具。
- 为获得最佳效果,请上传扩展名正确的干净文件,避免使用损坏的文档。
Choosing a compression level
Balanced is the recommended default for most everyday documents like contracts, reports and forms — it noticeably reduces file size while keeping images and text clear.
High quality is best when the PDF will be printed or contains detailed images such as photos or design work where quality matters more than file size.
Maximum and extreme compression are for cases where file size is the priority, such as fitting an email attachment limit or speeding up an upload on a slow connection.
常见问题
Which compression level should I use?
Balanced is best for most files. High quality keeps more detail for documents that will be printed, while maximum or extreme compression creates smaller files with more visible image quality reduction, best for email or web sharing.
Will PDF compression damage text?
Text usually remains sharp at every compression level. Image-heavy PDFs may show lower image quality depending on the selected compression level.
Can I compress scanned PDFs?
Yes. Scanned PDFs usually compress the most because they contain large page images, so this tool works especially well on scanned documents.
How much smaller will my file be?
It depends on the content. Image-heavy or scanned PDFs often shrink significantly, while text-only PDFs that are already small may see only a modest reduction. The exact percentage saved is shown after compression.
What is the maximum email attachment size for a compressed PDF?
Most email providers limit attachments to around 20-25 MB, though limits vary. Use maximum or extreme compression if your file needs to fit under a specific email or upload limit.
this PDF compressor 免费吗?
Yes, compressing PDF files with this tool is free, with no account required.
我上传的文件是私密的吗?
文件在处理期间以唯一的临时名称存储,旧的临时文件会自动清理。
我可以在手机上使用吗?
可以。上传和转换流程可在桌面、平板和手机浏览器上运行。