Compress PDF
Re-renders each page as an image at the quality you choose and rebuilds the PDF — scans and image-heavy files shrink a lot. Everything runs in your browser; the file is never uploaded.
Heads-up: after compression every page is an image, so text can no longer be selected, copied or searched. Don't use it on files whose text must stay editable. Password-protected PDFs can't be processed.
How to use
- Choose or drag in one PDF. The page shows its page count and original size.
- Pick a compression level. "Recommended" suits most files; "Strong" gives the smallest result; "Light" keeps more detail. You can also set the resolution and image quality yourself, and tick "Convert to grayscale" for black-and-white documents to save even more.
- Click "Compress". A progress bar follows the work page by page, and when it's done you'll see the size before, the size after and the percentage change.
- Happy with it? Click "Download compressed PDF". If not, change the settings and compress again — your original file is never modified.
How it works
The tool uses PDF.js to render each page as an image at the resolution you choose, saves it as a JPEG at the quality you set, and then uses pdf-lib to rebuild a PDF with the original page sizes. This approach works best on scans, documents assembled from phone photos and image-heavy brochures, which often shrink to between a tenth and a third of their size. Text-only PDFs exported straight from a word processor are already tiny and may actually get bigger; the tool tells you plainly when that happens.
When it's useful
Your email provider caps attachments at 20 or 25 MB. A government, school or tender portal accepts uploads of no more than 2 or 5 MB. Scanned contracts, IDs and invoices weigh in at tens of megabytes and are slow to send and preview in chat apps. Or you're archiving a lot of scans and want them to take up less space.
Tips
- Try "Recommended" first, check the result, then decide whether you need "Strong". For scanned text, 96–110 DPI is perfectly readable on screen.
- If the file will be printed, don't go below 150 DPI.
- When you're only slightly over a limit, lower the image quality first. When you're far over, lowering the resolution makes a much bigger difference.
- If you only need some pages, extract them with Split PDF first, then compress the smaller file.
Privacy
The entire process runs in your browser, and your PDF is never uploaded to a server. Contracts, medical records and financial statements can be compressed with peace of mind, and the data in memory is released when you close the page.
FAQ
Q: Are my files uploaded?
A: No. Rendering, compressing and rebuilding the PDF all happen locally; our server never receives your file.
Q: Can I still select and search the text afterwards?
A: No. Each page becomes an image, so text can't be selected, copied or searched, and links and bookmarks are lost. If you need to keep those, use the "optimise PDF" feature of a desktop PDF editor instead.
Q: Why did the file get bigger?
A: If the original is mostly vector text (exported from Word, for example), it's already very small and turning its pages into images makes it larger. Such files aren't a good fit for this tool — just keep the original.
Q: Can I compress to an exact target size?
A: Not directly yet. Compress once with the recommended settings, then lower the quality or resolution step by step; two or three tries are usually enough to get under a limit.
Q: Is it slow for long documents?
A: Every page has to be re-rendered, so a 100-page file typically takes a minute or two on an ordinary computer. Higher resolutions and phones are slower.
Q: Can I compress a password-protected PDF?
A: Files that require a password to open can't be read. Remove the password first, then compress.