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PDF & TÀI LIỆU

Nén Tài Liệu PDF

Tối ưu hóa và nén giảm dung lượng tệp tài liệu PDF để gửi qua email hoặc tải lên cổng dịch vụ công nhanh chóng mà không làm mờ nội dung văn bản.

Trạng thái công cụSử dụng xử lý máy chủ
Xem trước

Compression level

Hoặc kéo & thả PDFhoặc chọn tệp từ máy
.pdf · tối đa 40.0 MB. Xử lý trên máy chủ của chúng tôi rồi xóa ngay lập tức.

Low keeps the most detail in scanned pages and photos. High shrinks the most by also reducing large images' resolution.

Drop a PDF, choose a compression level, then compress it on the processing server.

Kết quả

Drop a PDF, choose a compression level, then compress it on the processing server.

Cách thức hoạt động

  1. Nhập dữ liệu của bạn

    Điền các giá trị cần thiết, dán văn bản hoặc tải lên tệp bạn muốn xử lý.

  2. Xem kết quả tức thì

    Hầu hết các công cụ cập nhật theo thời gian thực khi bạn nhập liệu; một số công cụ sử dụng một nút hành động duy nhất.

  3. Sử dụng kết quả

    Sao chép, tải xuống hoặc chia sẻ kết quả được tạo — bạn luôn có toàn quyền kiểm soát dữ liệu của mình.

Processed temporarily on our server — The PDF is sent to a ProntoUso server because recompressing embedded images needs real PDF and image libraries a browser cannot run reliably on its own. It is processed only in memory for that one request and is never written to disk or kept afterward.

Nén Tài Liệu PDF là gì?

Compress a PDF online by recompressing its embedded images and content streams, with Low, Recommended, and High levels, before-and-after size, and download.

TÌM HIỂU CÁCH HOẠT ĐỘNG CỦA CÔNG CỤ

How to compress a PDF

Shrink a PDF's file size by recompressing its embedded images, with three levels to balance quality against how much smaller the result gets.

How to use it

  • Drop a PDF up to 40 MB.
  • Choose a compression level: Low, Recommended, or High.
  • Compress, then compare the original and new size.
  • Download the compressed PDF.

What each level changes

Low re-encodes embedded images at a high JPEG quality without resizing them, keeping the most visual detail for the smallest guaranteed savings. Recommended balances quality and size, and also caps large images at 2000 pixels on their longest side. High goes further, using a lower JPEG quality and capping images at 1280 pixels, which shrinks photo-heavy or scanned PDFs the most.

What compression can and cannot do

  • Most of a PDF's size usually comes from its embedded photos or scanned pages, so those get recompressed; text, fonts, and vector graphics are only losslessly restructured, not degraded.
  • Small images such as icons and logos, transparent images, and black-and-white scanned pages are left untouched to avoid visible artifacts or a larger result.
  • A PDF that is already efficiently compressed, or has no images at all, may shrink very little — the tool never returns a file larger than what you uploaded.

Compression level example

Shrink a scanned report for email

A 12 MB scanned PDF compressed at the High level often lands well under half its original size, since scans are usually saved at a far higher resolution than a screen or printer needs.

12.0 MB -> ~4.5 MB

Processed temporarily on our server

The PDF is sent to a ProntoUso server because recompressing embedded images needs real PDF and image libraries a browser cannot run reliably on its own. It is processed only in memory for that one request and is never written to disk or kept afterward.

Các Câu Hỏi Thường Gặp (FAQ)

Is my PDF uploaded?

Yes. It is sent to a ProntoUso server for compression, processed in memory only for that one request, and never stored or logged.

Will compressing reduce quality?

Recompressing embedded images is lossy at the Recommended and High levels, so some image detail is traded for a smaller file. Text, fonts, and vector graphics are never degraded.

Why didn't my PDF get much smaller?

PDFs that are mostly text, already have efficiently compressed images, or use images too small to recompress safely (icons, logos) have little left to shrink. The tool never returns a result larger than the original.

Can I compress a password-protected PDF?

Only if it opens with no password at all — many PDFs are flagged encrypted just to restrict printing or editing. Genuinely password-protected files are not supported.

What happens to scanned black-and-white pages?

Bilevel (black-and-white) scanned images are left at their original encoding, since re-encoding them as JPEG typically makes text scans both blurrier and larger.

Công Cụ Liên Quan