PDF 转 TIFF

Yes. Check "Save as multi-page TIFF (single file)" and every page is written into one .tiff named after the PDF. Leave it unchecked and a multi-page PDF downloads as a ZIP containing page_1.tiff, page_2.tiff, and so on; a one-page PDF always gives a single .tiff.

The slider runs from 72 to 600 and defaults to 300, the usual choice for print and archival scans. Fax and document management systems typically expect 200 to 300, and 150 is enough for screen use. Very high DPI on large pages can run the browser out of memory, and you'll see an error if that happens.

LZW, the default, and Deflate are lossless and suit any content. CCITT Group 4 gives the smallest files for black-and-white scans and automatically switches the color mode to 1-bit. JPEG is lossy (quality 85) but keeps photo-heavy pages small, and PackBits or None are there for older systems that require them.

Set Color Mode to "Black & White (1-bit)" and Compression to CCITT Group 4, then pick 200 or 300 DPI. That combination is what most fax gateways and document management systems expect, and it produces very small files.

TIFF stores a bitmap of every page. An uncompressed 300 DPI color Letter page is roughly 25 MB, so lower the DPI, switch the color mode to grayscale or black and white, or use CCITT Group 4 for text scans. If you only need lossless images for the screen, PDF to PNG makes smaller files.

No. This tool takes one PDF at a time; if you drop several, only the first is used. Convert them one after another.

Yes. If the PDF needs a password to open, you're asked for it before conversion, and the pages are rendered once it's entered. The TIFF output itself has no password protection.

No. Pages are rendered with PDF.js and encoded with libvips compiled to WebAssembly, all inside your browser. That does require a browser with SharedArrayBuffer support, which is why the tool must run over HTTPS.