Compress PDF files
Reduce PDF file size in your browser — no uploads, no watermark.
Runs 100% in your browserHow to compress a PDF
- Open a PDF. Select the PDF you want to make smaller.
- Pick a quality. Choose Low, Medium or High. Lower means a smaller file and lower resolution.
- Compress and download. Click Compress to rebuild a smaller PDF in your browser and download it.
Why PDFs get too big
An oversized PDF usually has one cause: high-resolution images. A document scanned at 600 DPI, or built from phone photos, embeds far more pixel data than any screen — or most printers — will ever show, and that bulk is what bounces the file off a 10 MB email limit or clogs a shared drive. Text and vector graphics are tiny by comparison. So shrinking a PDF is mostly about dealing with those embedded images sensibly, which is exactly what this tool targets.
How this compressor works — and its honest trade-off
This tool takes the most reliable browser-based approach: it renders each page to an image at the resolution (DPI) you pick, re-encodes it as a JPEG, and assembles those into a new PDF. By replacing oversized embedded scans with a screen-appropriate image, it can cut scanned and photo-heavy files by 50–90%. The honest trade-off — stated plainly because it matters — is that rasterizing flattens everything into a picture: selectable text, searchable content and fillable form fields all become part of the image. That's a perfect deal for a scanned receipt or a photo-laden brochure, and a bad one for a text document you still need to search or edit.
Choosing a setting — and when to keep the original
The quality control is really a DPI dial. Low (96 DPI) is for scans you only need to read on screen or email; Medium (144 DPI) is the balanced default that stays crisp on most displays; High (200 DPI) preserves detail for documents that may be printed. Because the result depends entirely on the input, the tool shows you the before/after size — if a file doesn't shrink meaningfully, or it's a lightweight text PDF that would only lose its selectable text, keep your original. Compression is a tool to reach for deliberately, not a button to press on every PDF.
Private, and related tools
Everything runs locally with a bundled library, so your document — often a scanned ID, statement or contract — never leaves your device and nothing is stored. If your file is large because of the photos going into it, compressing those first with the image compressor before you build the PDF preserves text and often beats compressing the finished document. To split out just the pages you need (a smaller file with no quality loss), use the split PDF tool, or extract pages as images with PDF to JPG.
Frequently asked questions
- No. Compression runs entirely in your browser — each page is rendered and re-encoded locally. The file never leaves your device.
- Each page is rendered to an image at the resolution (DPI) and JPEG quality you choose, then those images are assembled into a new PDF. Re-rendering at a sensible screen resolution is the most dependable way to shrink scanned and image-heavy PDFs in a browser, because it removes the oversized embedded scans that make them huge.
- No — and this is the key trade-off. Because every page is rasterized to an image, selectable text, searchable content and form fields become part of the picture. Use this when a smaller file matters more than editable text, and keep your original if you still need copy-paste or fillable fields.
- If your PDF is mostly real text (an exported document, an ebook, a code listing), rasterizing it will usually make it larger and strip the selectable text — keep the original instead. This approach shines on scans and photo-heavy PDFs, not on lightweight text documents.
- It depends entirely on the original. Scanned documents and photo-heavy PDFs often shrink by 50–90%. A PDF that is already compact text may not shrink much — or could grow — in which case the tool tells you, and you keep the original.
- Start with Medium (144 DPI), which reads cleanly on screen. Drop to Low (96 DPI) for scans you only need to view or email; choose High (200 DPI) to keep more detail when the document may be printed. Higher DPI means a larger file, so it is a direct size-versus-sharpness dial.