Compression runs in your browser so we do not host every PDF. Your file is not uploaded by default.
Add a PDF on this page with drag-and-drop or the file picker. The compressor loads after you choose a file, not when the page first opens. Compression does not start until you review the analysis.
The page inspects image, font, content-stream, and metadata bytes in your browser and shows how much each layer holds. That breakdown is a ceiling, not a promised saving.
Quick presets are Lossless, Balanced, Small, and Rewrite streams (qpdf-style stream rewrite that keeps text selectable and does not remove passwords — use Unlock PDF for that). Fine control toggles image, stream, and metadata layers and an optional target size. Rasterize pages is a peer mode: every page becomes a JPEG with quality and longest-edge controls (text may not stay selectable). Font subsetting is listed but not available yet. Files over the published limits are rejected with a clear error instead of a silent fallback.
Processing runs in a Web Worker on this device after you press Compress. We keep that work local so we do not pay to compress every upload on our servers. By default the PDF is not uploaded. Optional: open DevTools, select Network, and confirm the file was not posted.
By default, no. Compression runs in your browser so we do not host or transform every PDF on our servers. Open DevTools, select Network, compress a file, and confirm the PDF is not posted to a remote host. Static page assets may still load from this site; the PDF itself is not sent on the default path.
Compression runs in a Web Worker inside your browser. Local processing is how we avoid server-side PDF jobs. The page does not send the PDF to a server on the default path, and the heavy compressor code loads only after you choose a file. Compress is a form with presets and options— it does not use a page-card board like Merge, Split, or Organize.
The current limits are 100 MB and 200 pages. Larger files are rejected with a clear error; they are not silently truncated or returned as if compression succeeded.
Lossless recompresses Flate content streams without re-encoding images. Balanced and Small also recode JPEG images, including ICC-based photos, and can make those photos look softer. Rewrite streams recompresses loosely stored content streams without removing passwords. Rasterize pages turns each page into a picture: the file can shrink far more, but text may not stay selectable and the pages get blurrier. After inspect you can use Fine control to turn image, stream, and metadata layers on or off. Font subsetting is shown in the makeup but is not applied yet. Vector-heavy pages shrink when streams were stored at a weak zlib level; simplifying Bézier paths is not available. There is no fixed compression ratio.
After the page analyzes the PDF, Fine control lets you set an optional target size on this Compress PDF page and run compression in your browser. If the PDF cannot reach that size, you get an explicit result instead of a silently unchanged file. Size-specific URLs are not separate live pages.
Encrypted PDFs and files that need a password to open are rejected with a clear error on this Compress PDF page. Use Unlock PDF first for permission-only locks or when you already know the open password, then come back to compress. This site does not recover or guess passwords.
After inspect, look at the size makeup. This engine recodes JPEG images (including ICC-based photos and soft masks), recompresses Flate streams, and can strip metadata. It does not subset fonts, does not rewrite vector paths, and skips fax/JBIG2/JPEG2000 image streams and many 1-bit scans. A font-heavy CJK file or a CCITT scan can stay almost the same size even on Small. That is an honest limit, not a silent failure.
You can shrink an email attachment or a resume PDF on this same Compress PDF page. There is no separate email or resume URL; pick a smaller preset or a target size here. How small the file gets depends on how the PDF was built. Government 100 KB / 200 KB portals often need scan formats this compressor still skips—use the makeup and the explicit unreachable result instead of expecting a guaranteed size. A personal Gmail account allows 25 MB of attachments; Google states that at https://support.google.com/mail/answer/6584. Outlook.com allows 25 MB for the whole message, including the text; Microsoft states that at https://support.microsoft.com/en-us/outlook/sending-limits-in-outlook-com. A work account can set a different limit.
You can compress a PDF in a mobile browser that can run this page. Very large PDFs can still fail if the device runs out of memory; try a smaller file or a desktop browser in that case.
Compress PDF is free in your browser and does not use credits. You still have to stay within 100 MB and 200 pages. No account is required.