Compress PDF & Reduce File Size
Make it smaller without uploading it. Text, links and forms keep working.
Runs on your device. Nothing is uploaded.
Drop a PDF here
PDF · processed on this device
Add several files to compress them all at once.
Why compress PDFs?
Large PDFs cause real problems. Email bounces, slow uploads, storage limits. Balanced reduces those file sizes while keeping visual quality high and document features intact.
Email attachments
Many email services cap attachments around 20–25 MB. A compressed PDF slides through without issues.
Faster uploads
Uploading to Dropbox, Google Drive, or a client portal? Smaller files mean less waiting.
Save storage
Archiving years of documents? Compression can cut storage costs significantly.
How PDF compression works
Select your PDF
Drag and drop or click to browse. Your file loads instantly — nothing is uploaded.
Choose a size
Smallest, Balanced or Best quality — each one showing the file it produces.
Download the result
Your compressed PDF is ready in seconds. Compare file sizes and save.
Need a specific size? Set a target such as 10 MB, 5 MB or 2 MB and Lyonite will find the highest-quality result that can reach it — it never switches to the most aggressive setting behind your back to hit a number, and tells you when a target is out of reach.
What actually gets compressed?
The pictures. Each image is measured at the largest size it is actually drawn. Photographs compete as mozjpeg candidates; charts, screenshots and flat graphics get a lossless candidate so crisp edges are not traded for JPEG ringing. CMYK, ICC and custom-decode images are rendered through the PDF engine itself rather than guessed at, and every candidate is measured against the original before it is kept.
The fonts. Supported Type0 TrueType fonts are safely subset with HarfBuzz while retaining their original glyph IDs and layout features. Other font arrangements are kept. Unused font tables are stripped only where the PDF renderer does not depend on them.
The copies. Documents assembled from several sources routinely store the same thing twice. One research paper embeds the same 379 KB font program three times, byte for byte — 11% of the file held by two objects indistinguishable from one already there. Those are compared byte by byte, not by a checksum, and merged.
The container. On a document with no photographs in it this is the whole saving. Page content is re-deflated and packed into efficient object streams; streams the file left uncompressed — usually its metadata — get compressed; and the file is written back out with its objects and its cross-reference table packed the way the format allows instead of the way most libraries default to. On IRS Publication 17 that cross-reference table alone goes from 147 KB to 3 KB. Balanced changes how the PDF is stored, not what the document says or how its features work.
Balanced keeps the document. Pages are never rendered to images. Text, links, forms, annotations, bookmarks and accessibility structure come through. Smallest is a separate, deliberate mode: it may remove accessibility structure, metadata, thumbnails and materially large non-visual attachments, and its result names those losses. Some compressors delete the tag tree without saying so; we measured that — iLovePDF and Smallpdf removed it on the settings a free visitor gets, and Ghostscript removed it at every preset we tried. PDF24 kept them all. Balanced does not remove them.
Any image that would grow keeps its original bytes, and so does the whole file: if the result is not smaller, you get the source back.
Frequently Asked Questions
How much smaller will my PDF get?
It depends on the file. Scans and image-heavy PDFs have the most room; text-heavy ones shrink through their fonts, which is often more than people expect. You do not have to guess — the estimated size is on screen before you press the button and moves as you change the setting.
Will my PDF look worse after compression?
Balanced never flattens a page: selectable text and vector art stay as text and vectors, while suitable photographs are tested against smaller image candidates. Smallest can reduce image detail more aggressively. The preview shows page one of the file you would actually get, so you can judge that trade before saving it.
Can I compress a PDF to a specific size?
Yes. Type the size you need — 10 MB, 5 MB, 2 MB, whatever the upload limit is — and Lyonite picks the highest quality that fits under it. It will not quietly switch to the most aggressive setting to hit a number: if the target cannot be reached without removing things, it tells you and hands back the best result it could reach.
Can I compress password-protected PDFs?
Not directly. If the PDF is encrypted, you'll need to remove the password first (using Adobe Acrobat or similar). Once it's unprotected, compression works normally.
Are form fields and links preserved?
Balanced preserves links, form fields and values, annotations, bookmarks and the tagged structure screen readers depend on. Smallest still keeps visible pages and searchable text, but may remove non-visual accessibility and metadata records; the result lists what changed. Compressing any signed PDF invalidates its existing signature, and Lyonite warns before starting.