About Compress PDF
Compress PDF reduces the file size of a PDF document so you can email it, upload it to systems with attachment limits, or save storage space. The tool optimizes embedded images, removes duplicate streams, and flattens unnecessary object overhead — without visually changing the document for typical reading use.
Three compression levels let you trade quality for size: Low for minimal visible change (good for text documents), Medium for balanced results (the default), and High for maximum reduction (images become slightly softer but remain readable). Compression runs entirely in your browser — your source PDF isn't uploaded anywhere.
How it works
- Upload the PDF you want to shrinkDrop your file — its current size is displayed so you can compare to the output.
- Pick a compression levelLow preserves maximum quality; High gives the smallest file. Medium is the default and works for most documents.
- Click CompressThe tool re-optimizes images, removes redundancy, and rewrites the PDF — all locally. Typical files shrink 30–70% depending on image content.
When to use Compress PDF
Emailing attachments that exceed provider limits
Gmail caps attachments at 25 MB and many corporate systems are stricter. Compress reduces typical scanned PDFs well under the limit.
Uploading to forms with size restrictions
Visa applications, online tax portals, and job application sites often limit PDFs to 2–5 MB. Compress to fit.
Archiving PDFs with limited cloud storage
When your Dropbox or Google Drive is full, compressing large PDFs can reclaim significant space.
Speeding up sharing links
A 2 MB PDF loads in seconds; a 30 MB PDF makes recipients wait. Compress before sharing for a better recipient experience.
Frequently asked questions
How much will my file shrink?
It depends on content. Text-heavy documents shrink modestly (10–30%); image-heavy PDFs (scanned documents, brochures) often shrink 50–80% at Medium quality.
Will compression affect text readability?
No. Text is not compressed lossy — it remains crisp and searchable at every compression level. Only embedded images lose some quality, and only at High compression noticeably.
Which level should I pick?
Medium for most documents. Low if the PDF is print-destined or already small. High if you need the smallest possible size and some image softening is acceptable.
Can I compress a compressed PDF further?
Usually not by much — the second pass of compression has diminishing returns. If you need a smaller file, try a higher compression level on the original instead of re-compressing.
Does the tool work on password-protected PDFs?
No. Unlock the PDF first (using our Unlock PDF tool, if you have the password), then compress.