Compress PDF

Compress PDF is a free, browser-based tool that reduces the file size of a PDF document. Most PDFs are large because of the images inside them - high-resolution scans, screenshots, and photos can each add megabytes. This tool re-encodes those images at a more efficient quality and removes redundant data, so the same document takes up far less space.

Everything runs locally in your browser. When you add a file, it is processed on your own device using JavaScript - it is never uploaded to a server, never stored, and never seen by anyone but you. That makes it safe for contracts, invoices, medical records, and any other document you would not want to hand to a third-party website.

The result is a smaller PDF that still opens in every reader, keeps its pages and text, and is easy to email or upload. You control how aggressively it compresses, so you can trade a little visual quality for a lot of saved space when you need to.

The main reason people compress a PDF is a hard limit somewhere else. Email providers cap attachments (Gmail at undefined MB, many corporate systems lower), web forms reject files over a few megabytes, and portals for job applications, visas, or tax filings often demand a PDF under a specific size. A undefined MB scanned document simply will not go through until you shrink it.

An online tool means you do not have to install Acrobat or any desktop software, buy a license, or wait for a heavy app to launch. You open a web page and drop in a file. Because this tool runs entirely in the browser, it also avoids the biggest drawback of most "online" compressors: uploading your private document to someone else's server.

Smaller files also load faster on the web, sync quicker to cloud storage, and cost less to store at scale. If you are sending the same brochure or report to hundreds of people, or archiving thousands of documents, trimming each one adds up quickly.

1. Add your PDF. Drag it onto the drop zone or click to browse. Processing starts on your device the moment it loads.
2. Choose a compression level. A lighter level preserves image detail and is best for documents you will print; a stronger level maximizes size savings and is best for on-screen reading and email.
3. Run the compression. The tool re-encodes images and strips unused objects, then displays the new size alongside the original so you can see exactly how much you saved.
4. Review and download. Open the preview or the saved file and confirm text is sharp and images are acceptable, then download the compressed PDF.

If the result is still too large, run it again at a stronger setting, or split the document and compress the heaviest pages separately. If quality dropped too far, step back to a lighter level and accept a slightly larger file.

• Email attachments. Get a scanned contract or a photo-heavy report under the undefined MB Gmail limit, or under a stricter corporate cap.
• Online forms and portals. Meet the size limits on job applications, university submissions, visa uploads, and government e-filing systems.
• Scanned documents. Phone-scanned pages and flatbed scans are often huge; compression cuts them down dramatically with little visible change.
• Web publishing. Serve lighter PDFs so brochures, menus, and whitepapers download quickly for visitors.
• Cloud storage and archiving. Fit more documents in the same space and speed up sync across devices.
• Sharing over chat. Send PDFs through messaging apps that reject large files.

Many workflows pair compression with other steps. You might merge several PDFs into one file and then compress the combined document, or compress a PDF before converting it with PDF to Word.

• Match the level to the destination. Screen-only and email files can take heavy compression; anything you will print should stay lighter to keep images crisp.
• Start moderate, then go stronger. Try a middle setting first, check the result, and only increase compression if you still need to hit a size target.
• Know what drives the size. Text and vector graphics are already tiny - it is embedded images that make PDFs big. If your PDF is mostly text, expect smaller savings.
• Keep an original. Compression is lossy for images, so always keep the source file in case you need full quality later.
• Check text and small print. After compressing, verify that fine text, stamps, and signatures are still legible before sending.
• Compress last. Do your edits, merges, and page reordering first, then compress once at the end so you are not re-compressing an already-compressed file.

Yes. This tool does the entire job inside your browser tab. Your PDF is read into memory on your own device, compressed there, and handed straight back to you as a download. Nothing travels over the network - there is no upload, no server-side copy, and no account required.

That design matters for sensitive material. Contracts, financial statements, ID scans, and internal reports never leave your control, so there is no third party to trust with them and nothing to delete afterward. It also means the tool keeps working offline once the page has loaded, and it is fast because there is no upload or download round-trip to wait on.

Because the work happens locally, performance depends on your device and the file size. Very large PDFs may take a few seconds and use some memory while they process, but they never leave your machine.