Choose how the PDF should be reduced
Safe optimise rewrites the PDF structure without intentionally lowering page quality. Strong scan compression redraws each page as a JPEG image, which can shrink scanned files more but removes selectable text and may soften small details.
Drop one PDF here
or click to choose a file from your device
Use the lightest method that meets your upload limit
Start with safe optimise when the PDF contains selectable text, links or computer-generated pages. It may save only a little space, but it avoids turning every page into a picture. Use strong scan compression for camera scans, photographed receipts or image-only documents when a portal rejects the original file.
Try safe mode
Download the result if it is smaller and still meets the receiving portal's limit.
Use strong mode only if needed
Choose balanced settings first, then inspect names, numbers, QR codes and fine print.
Verify before submission
Open the downloaded PDF at 100% zoom and keep the original until acceptance.
What strong mode changes
Each page is rendered and saved as a JPEG inside a new PDF. This is effective for large scans, but selectable text, internal links, bookmarks, form fields and digital signatures may be lost or invalidated. Never overwrite the only copy of an important signed or archival document.
Compression happens in the current browser tab. Large PDFs need substantial memory, especially on phones; if the page becomes slow, close other tabs or use a computer.
PDF compression that shows the real result
A useful compressor should not pretend that every document can be reduced to the same target. A PDF exported from Word may already be small, while a phone scan can contain a full-resolution photograph on every page. That difference is why this tool reports the original size, output size and actual saving instead of promising an exact number.
Safe optimise and strong scan mode are different jobs
| Mode | Best for | Important trade-off |
|---|---|---|
| Safe optimise | Computer-generated PDFs, invoices, quotations and text documents | Preserves page content but may produce little or no saving when the file is already efficient |
| Strong scan compression | Camera scans, photographed receipts and image-only pages | Redraws pages as JPEG images; text selection, links, form fields and fine detail may be lost |
Start with safe optimise. If the receiving portal still rejects the file and the document is mainly scanned images, return to the original and try strong mode with balanced settings. Do not repeatedly compress a previously compressed copy; each strong pass can make small text harder to read.
Why “compress PDF to exactly 100 KB” is not guaranteed
File size depends on page count, image detail, colour, fonts and the internal structure of the source PDF. A one-page black-and-white scan may fit below 100 KB, while a ten-page colour statement may not remain readable at that size. The receiving portal's limit is a maximum, not a reason to destroy necessary information. If only a few pages are required, use Split PDF first and then compress the smaller document.
If the preview does not load
The upload is now checked by the core PDF reader rather than the thumbnail preview. When the file name and page count appear, safe optimise remains available even if the browser cannot draw page thumbnails. Strong scan mode needs the preview renderer because it must redraw every page; if that component is blocked, choose safe optimise or try a current desktop browser.
Review these details at 100% zoom
- Names, account references, dates and totals.
- QR codes, barcodes, stamps and thin signatures.
- Small terms printed near the page edge.
- The first and last page, plus the final page count.
Keep the original file until the destination accepts the result. Rewriting a digitally signed PDF can invalidate its cryptographic signature even when the visible page looks unchanged. Compress before signing, or send the original signed file when verification is required.
Browser processing and privacy
The compression operation runs in the current browser tab; the site does not provide a server upload endpoint for this tool. The webpage still loads normal services used by the website, including analytics, advertising and the local scripts that power the PDF functions. Review the Privacy Policy and follow your organisation's document-handling rules for confidential files.
Why was the original kept?
If a newly generated file is larger, the tool keeps the smaller original bytes and reports that no useful reduction was found.
Does strong mode keep searchable text?
No guarantee. Strong mode places a JPEG image of each page into a new PDF, so text search and selection may disappear.
Can a phone compress a large PDF?
Small files usually work, but long scans can exceed mobile memory. A laptop or desktop is more reliable for large image-heavy documents.