Compress PDF Online
Shrink PDF files right in your browser — free, no upload required — 100% private — your files never leave your device.
✓ Your file never leaves your device. Everything runs locally in your browser.
Large PDFs are awkward to email, upload to portals or share. This tool rebuilds a PDF at a smaller size by re-rendering each page as an image and packing it into a new document. Because the whole process runs in your browser, the file is never sent to a server.
It works best for scanned documents, photo-heavy PDFs and exports from design tools. Documents made mostly of vector text may not shrink much — and can even grow — so compare the result before replacing the original.
How it works
- Choose a PDF – pick a .pdf file from your device.
- Choose a level – strong for the smallest file, light for the best quality.
- Compress – click Compress to rebuild the PDF.
- Download – save the compressed PDF and check the size shown.
What do the levels mean?
| Level | Resolution | Quality | Best for |
|---|---|---|---|
| Strong | Lower | Smallest file | Email attachments, web uploads |
| Balanced | Medium | Good | Everyday documents and scans |
| Light | Higher | Best | Readable text, archiving |
Privacy
Contracts, invoices and ID documents are sensitive. Unlike most online PDF services, FormatFlash does not upload your file: PDF pages are rendered and rebuilt locally, so nothing leaves your device.
Frequently asked questions
Is my PDF uploaded?
No. The PDF is processed entirely in your browser; nothing is uploaded.
How does PDF compression work here?
Each page is rendered to an image and rebuilt into a new PDF at a chosen quality. This works especially well for scanned and image-heavy PDFs.
Will the text stay selectable?
No. Compression rasterises the pages, so text becomes part of the image. The layout and appearance are preserved.
Why is my PDF bigger afterwards?
PDFs that already contain compressed images or mainly vector text can grow. In that case, keep the original file.
Related tools
Compress your PDF now — free, private and without uploading a single file.