PDF Tools

No. All processing happens 100% in your browser using pdf-lib and pdfjs-dist. Your files never leave your device — there is no upload, no server, and no storage of your documents.

There is no hard limit, but files over 100 MB may cause your browser to slow down since everything runs locally. For best results, keep files under 100 MB. If you have very large PDFs, consider splitting them first.

Results vary widely depending on the PDF content. Text-heavy PDFs with metadata see the best results (10–40% reduction). PDFs that are mostly scanned images see minimal reduction since the image data cannot be re-encoded without a dedicated compression library.

No. Password-protected PDFs cannot be opened or processed without the password. You would need to remove the password protection with a dedicated tool before merging.

72 DPI is fine for screen previews and web thumbnails. 150 DPI is a good balance for general use. 300 DPI is recommended for print-quality output or OCR. Higher DPI means larger file sizes and slower processing.

No. Our compression removes metadata and optimizes document structure without re-encoding images. The visual quality of your PDF remains identical after compression.

No. Once you download the modified PDF, the changes are permanent in that file. Your original file is never modified — all operations create a new output file, so you always keep the original.

You can split into individual pages (1 page per file) or any chunk size up to the total number of pages. The resulting files are packaged as a ZIP archive for easy download.