How PDF compression works here
This tool renders each page of your document to an image, recompresses that image as JPEG at the quality you choose, and rebuilds the PDF from the results. That approach is effective on the documents people most often need to shrink — scans and image-heavy files — because in those the images are essentially the whole file.
It comes with an important consequence you should understand before using it. Because pages become images, any selectable text in the original becomes part of a picture. The result cannot be searched, copied from, or read by a screen reader. For a scanned document that was already an image, nothing is lost. For a text document exported from a word processor, this is a real downgrade and usually the wrong tool.
When to use it
Use it for scanned paperwork, photographed documents, presentation exports and anything where the file is large because it contains photographs. These compress dramatically, often by seventy percent or more, with no visible difference at normal viewing size.
Avoid it for contracts and reports where text needs to remain selectable, for documents that must remain accessible to screen readers, and for files containing fine line work or small text that will be printed. In those cases, the better route is usually to compress the source images before creating the PDF, or to export again from the original application at a lower setting.
Choosing settings
The quality slider controls JPEG compression of each rendered page. Around seventy percent is a reasonable balance for most scans. Below fifty, compression artefacts become visible, particularly around text edges.
The resolution scale determines how many pixels each page is rendered at, and it usually has a larger effect on file size than quality does. Reducing to seventy-five percent is generally imperceptible on screen. Fifty percent produces much smaller files but softens small text noticeably, so check the result if the document will be printed or contains fine print.
Why files need shrinking
Email attachment limits, typically twenty to twenty-five megabytes, are the usual driver. Government and university upload portals are often stricter still, sometimes capping at two or five megabytes, which a phone-photographed document exceeds immediately. Storage and bandwidth costs matter for documents published on a website, where a large PDF is a slow download for every visitor.
Processed on your device
Rendering and recompression happen entirely in your browser. Nothing is uploaded, which matters given that the documents most in need of compression are frequently scans of identification, financial statements and medical records. Long documents may take some time and will use noticeable memory, since every page is rendered locally.
Frequently Asked Questions
Will my text still be selectable after compressing?
No. Pages are converted to images, so text becomes part of a picture. Use this on scans rather than on text documents where selectable text matters.
How much smaller will my file get?
Scanned and image-heavy documents commonly shrink by seventy percent or more. Text-based PDFs may shrink little, or even grow, since they were already efficient.
Which setting should I change first?
Resolution scale usually has the bigger effect on file size. Seventy-five percent is generally imperceptible on screen.
Is my document uploaded?
No. Rendering and compression happen entirely in your browser, so sensitive scans never leave your device.
Why did my PDF get bigger?
Text-only PDFs are already highly compressed. Converting their pages to images can increase size. This tool is intended for scans and image-heavy files.