Compress PDF Online — Free & 100% Private
Shrink large PDF files in seconds, right inside your browser. Your document is never uploaded to a server — all compression happens on your device. No accounts, no watermarks, no limits.
🗜️ Compress a PDF now →How to compress a PDF for free
- Open the Moriaki PDF compressor — no download or install needed.
- Drag and drop your PDF (or click to select it). It loads instantly in your browser.
- Choose a compression level — High, Medium, or Low — depending on how small you need it.
- Click Compress and download your smaller PDF. Your file never leaves your computer.
Why compress PDFs with Moriaki?
Most “online” PDF compressors upload your file to their servers, process it there, and ask you to trust that they delete it afterward. For contracts, IDs, or financial statements, that’s a real privacy risk.
Moriaki PDF is different: every operation runs locally in your browser. You can even disconnect from the internet after the page loads and the compressor still works — proof that your document never touches a remote server.
Smaller files are easier on everyone. A lighter document attaches to an email without bouncing, uploads to job portals and government forms that enforce strict size caps, and opens faster on a phone with a weak connection. It also saves storage in shared drives and inboxes that fill up quickly. Because the work happens on your own device, the speed depends on your computer rather than a busy server or a slow upload, so even a long scanned report is usually ready in moments. Try a medium setting first, check the result, and only push harder if you still need the file smaller.
Frequently asked questions
Is it really free to compress PDFs?
Yes. Moriaki PDF is completely free with no accounts, no daily limits, and no watermarks added to your files.
Are my files uploaded anywhere?
No. Compression happens entirely in your browser on your own device. Your PDF is never sent to or stored on any server.
How much smaller will my PDF get?
It depends on the file. Image-heavy PDFs can shrink dramatically (often 50–90%) on the High setting. Choose Low or Medium to keep more detail.
Will compressing reduce quality?
Higher compression re-encodes page images at a lower quality to save space. For the best balance, start with Medium and increase only if you need a smaller file.
Does it work on mobile?
Yes — it runs in any modern browser on desktop, tablet, or phone, with no app to install.
How it works, step by step
Add your file
Drop it in. The document opens inside your browser and is never sent to a server.
Pick a level
Choose High, Medium or Low, depending on where the file is going.
Download
Save the smaller version instantly. Your original stays untouched on your device.
A file that is too large to email or upload is one of the most common document headaches. Most people fix it by sending the document to an online converter — handing private paperwork to a third-party server just to make it smaller. Here you can compress a PDF online entirely inside your browser, so nothing ever leaves your computer.
Why files get big — and what shrinking does
The size of a document is almost always dominated by images. A 20-page text contract might be only a few hundred kilobytes, while a 20-page scan is really twenty high-resolution photos saved together, and can run to tens of megabytes. Shrinking it works by re-encoding those images at a lower quality and reducing oversized scans, which is where nearly all the savings come from. Text-based files are already small, so there is little to squeeze — if one is somehow huge, the culprit is usually an embedded scan or an oversized font set.
Moriaki vs. typical online tools
| Moriaki | Typical online tools | |
|---|---|---|
| Your file uploaded to a server | Never | Usually yes |
| Account required | No | Often |
| Watermark on your result | None | Common on free tiers |
| Daily limits | None | Common |
| Works offline | Yes | No |
| Price | Free | Free / freemium |
Making a file smaller is a trade-off between size and visual quality, which is why good tools offer levels. For something that will be emailed or viewed on screen you can go aggressive; for anything that will be printed, stay gentle. Under the hood this relies on the open document format and on image compression — and because it all runs on your own machine, there is no upload wait and no copy of your paperwork left behind.
Compress PDF online — frequently asked questions
Is it free?
Are my files uploaded anywhere?
How much smaller will it get?
Will it reduce the quality?
Will it change my original?
Can I use it on my phone?
