Everything on this site runs in your browser — which is the point, and also the limit. Some jobs need a real engine, real memory and a verifying second opinion. Here is the honest split.
| Tool | Why it needs the desktop |
|---|---|
| OCR — make scans searchable | Full Tesseract engine with bundled languages; browser OCR is too slow and heavy for real documents. |
| Real compression | Image downsampling with quality presets and compress-to-target-size; the web tool only optimizes structure. |
| Verified redaction | Content is genuinely removed from the file, then the output is searched to prove it — a guarantee that needs a verifying engine. |
| PDF/A conversion | Archival conformance requires a full conversion engine. |
| Form filling | Reads and writes AcroForm fields with correct appearance streams. |
| Flatten forms & annotations | Bakes interactive content into the page so it renders identically everywhere. |
| Overlay / letterhead | Stamps one PDF behind or over another with vector fidelity. |
| Bookmarks: editor, outline pane, heading suggestions, split-by-chapter | Full outline reading and writing. |
| Scan cleanup — grayscale + deskew | ImageMagick-grade processing at print resolution. |
| Split double-page scans | The book-scan splitter, rotation-aware. |
| Remove blank pages (detected) | Brightness analysis selects the blanks for your review. |
| N-up collage & interleave scanned sides | Print imposition and front/back merging for scanner workflows. |
| Bates numbering with live preview | Legal-grade stamping, previewed on the real page before writing. |
| Batch processing | One operation across many files, failures isolated. |
| 500+ page documents | A browser tab runs out of memory where a desktop process does not. |
| Validated output — every file | Everything written is re-opened and verified by a second, independent PDF engine before success is reported. |
Merge · Split (ranges / by size) · Rotate · Extract & remove pages · Organize with thumbnails · Images ↔ PDF · Page numbers · Watermark · Crop · Resize (A4 ↔ Letter) · Booklet · Remove metadata · Protect & unlock (AES-256) · Repair · Compare
The PDF Toolbox desktop app compresses, redacts with verified removal, OCRs scans, repairs damaged files, converts to PDF/A and handles 500-page documents — all offline, on your machine, with the same promise: nothing ever leaves it. See everything it does →