Your files never leave your device
Most online PDF tools upload your document to their servers. This one doesn't: the PDF is read, edited and saved by JavaScript running in this browser tab, and the site's Content-Security-Policy blocks the page from sending data anywhere. That makes it safe for contracts, payslips, invoices and internal reports. Works offline once the page has loaded.
How compression works
Lossless rewrites the PDF with compressed object streams and drops unused data. Nothing visible changes, but savings are usually modest (0–20%) because the bulk of most PDFs is images and fonts that are already compressed.
Medium, Strong and Extreme render every page to a JPEG at a lower resolution and rebuild the PDF from those images. This is what makes scanned documents and image-heavy slide decks dramatically smaller, at the cost of selectable text. If a PDF is mostly text, the lossless option usually gives the better result — the tool tells you if the "compressed" file came out larger.
Command-line equivalents
For scripts and CI pipelines, the same operations with qpdf and Ghostscript:
# Merge
qpdf --empty --pages a.pdf b.pdf -- merged.pdf
# Extract pages 1-3 and 7
qpdf in.pdf --pages . 1-3,7 -- out.pdf
# Split into one file per page
qpdf --split-pages in.pdf page-%d.pdf
# Rotate page 2 by 90°
qpdf in.pdf out.pdf --rotate=+90:2
# Compress (screen ≈ 72 dpi, ebook ≈ 150 dpi, printer ≈ 300 dpi)
gs -sDEVICE=pdfwrite -dPDFSETTINGS=/ebook -dNOPAUSE -dBATCH -o out.pdf in.pdf
# Remove a password (you must know it)
qpdf --password=secret --decrypt locked.pdf unlocked.pdf
# Strip metadata
exiftool -all:all= -overwrite_original file.pdf && qpdf --linearize file.pdf clean.pdfLimits
- Password-protected PDFs can't be opened. Remove the password first (see
qpdf --decryptabove). - Very large files (hundreds of MB) are limited by your browser's memory. Desktop browsers handle typical 50–100 MB documents fine.
- Watermark text uses a built-in font, so it supports Latin characters only.
- Merging and splitting keep page content, links and annotations, but bookmarks and fillable form fields are not carried over.
- PDF to Word/Excel isn't offered: reliable conversion needs server-side processing, which would mean uploading your file.