Make a PDF smaller so it fits an email attachment — on your device. Works best for scanned or image-heavy PDFs. No upload, no sign-up.
Drop PDF files here
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🔒 Compressed on your device · 0 bytes uploaded
How it works
ConvertCabin runs the open-source PDF engines (pdf-lib and pdf.js) inside this browser tab, so your PDF is read, transformed and re-saved entirely on your device. Nothing is uploaded — no queue, no daily cap, no account.
Most PDF sites upload your document to a server first. Because ConvertCabin works locally, it stays free, unlimited and private — and keeps working offline once the page has loaded.
How this compresses
This re-renders each page as a compressed image and rebuilds the PDF, which dramatically shrinks scanned and image-heavy documents. Because pages become images, the text is no longer selectable — so it's ideal for scans and photos, and less suited to text documents where you need to copy or search the text.
Frequently asked questions
How do I compress a PDF?
Drop your PDF, choose a quality (lower means smaller), and download the compressed file — all in your browser.
Why is the text no longer selectable afterwards?
Compression works by turning each page into a compressed image, which removes the selectable text layer. If you need selectable text, keep the original.
Is my PDF uploaded?
No. Everything is rendered and rebuilt on your device; your file never leaves your machine.
What is a PDF file?
PDF (Portable Document Format) preserves a document's exact layout, fonts, and images on every device and operating system, which is why it's the standard for sharing files that must look identical everywhere.
Can I compress a PDF without uploading it?
Yes — that's exactly how this tool works. The compression runs in your browser, so the PDF never leaves your device. You can even disconnect from the internet after the page loads and it will still compress.
How do I compress a PDF to 100 KB?
Use a stronger compression level and re-run if needed. How small you can go depends on the content — image-heavy pages compress far more than pages that are already mostly text. If the first pass isn't under 100 KB, lower the image quality setting and run it again.