What is a PDF Compressor?
PDFs balloon when they contain large photos or scans. This compressor re-renders each page at a resolution and image quality you choose, typically cutting scanned documents to a fraction of their size.
Because compression re-renders pages as images, the output is ideal for sharing and archiving. For contracts that must keep selectable text, compress only when the size limit truly demands it.
Scanned documents are the classic case: a 10-page scan at 300 DPI easily exceeds 20 MB, while email caps sit at 25 MB and many government portals at 1-5 MB. Re-rendering at a sensible resolution and JPEG quality typically brings scans down 60-90% while staying perfectly readable on screen.
What gets flattened, and when that matters
Strong compression here works by re-rendering each page as an image, which is why the savings on a scan are so large. It also means the output is a picture of the document rather than the document. Before you compress, check that none of the following still has to work:
- Form fields. An AcroForm PDF stops being fillable: the boxes become part of the page image.
- Digital signatures. Re-rendering rewrites the file, which invalidates any cryptographic signature on it.
- Selectable and searchable text. Copy and paste stops working, and so does Ctrl+F, for the recipient as well as for you.
- Links and bookmarks. Clickable annotations do not survive the render.
When compression is the wrong fix
If you only need part of the document, splitting beats compressing: pulling three pages out of a forty page file cuts far more weight than re-encoding all forty, and the pages you keep stay exactly as they were.
If the file came from a scanner, the scanner setting is the better lever. Scanning a text document at 600 DPI in color and then compressing it is a slower route to a worse result than scanning it at 200 to 300 DPI in grayscale in the first place.
And if the PDF is large despite holding almost no images, the weight is usually embedded fonts or attachments rather than page content. Compression has very little to work with there, which is why a text-heavy file cannot be made smaller this way. When the result would be larger than the original, the tool keeps your original and says so.
Frequently asked questions
Which level should I pick for email?
Balanced handles most cases: a 20 MB scan usually lands well under 5 MB. Use Strong for strict portal limits, Light when the document has fine print or detailed diagrams.
Why did my text-only PDF not get smaller?
A text PDF stores text as small instructions, often a few kilobytes per page. This tool redraws each page as an image, and an image of a page is far heavier than the text it shows, so the result can be many times larger. The tool never gives you a bigger file: if the result is not smaller, your original is kept and you are told. It also warns you before compressing when it finds text, because text is no longer selectable or searchable afterwards. Compression pays off on scans and photo-heavy documents.
Is my PDF uploaded to your server?
No: the whole pipeline (reading, re-rendering, rebuilding) runs inside your browser.
Will text stay selectable?
No: pages are re-rendered as images to achieve strong compression, so text becomes part of the page image. Use it when file size matters more than selectable text.
How much smaller will my PDF get?
Scanned and photo-heavy PDFs often shrink 60-90%. PDFs that are mostly text usually cannot be made smaller by this tool, because redrawing text as images adds weight. In that case your original is kept, and the tool shows the before and after sizes either way.
Is there a page limit?
No fixed limit: very large documents just take longer since every page is processed on your device.