压缩 PDF
减小 PDF 的大小。
Upload a PDF to compress it. This basic compressor rasterizes each page to a JPEG at the quality you choose and rebuilds the PDF — best for scanned or image-heavy files. Text becomes non-selectable, and if the result isn't smaller the tool keeps your original. Everything runs locally in your browser.
工作原理
- 1 Drop a PDF, or click to choose one.
- 2 Choose a quality level (lower = smaller).
- 3 Click Compress.
- 4 Compare the sizes and download the result.
常见用例
- Shrink a large scanned document to email.
- Reduce an image-heavy PDF for upload.
- Fit a PDF under a size limit.
- Save storage on photo-based PDFs.
常见问题
Are my files uploaded to a server?
No. PDF processing happens locally in your browser with pdf-lib, so your files never leave your device and nothing is stored.
Why might my PDF not get smaller?
Text-based PDFs are already compact, so rasterizing them can make them larger. The tool detects this and keeps your original unchanged instead of pretending to compress.
Will text still be selectable?
No — this method flattens pages to images, so text is no longer selectable. It works best for scans and image-heavy PDFs. For other files, this is a deliberately simple first version.
Is it really free?
Yes — free, with no signup, no watermark and no limits.