Reduce PDF File Size without losing quality
Need to shrink a PDF, make a scan smaller, or fit a document under an email attachment limit? QuietPDF reduces PDF file size right inside this browser tab. Pick how aggressive you want to be, and the smaller file is handed straight back to you. No uploads, no signup, and your file never leaves your device.
How small can you make a PDF?
How much you can shrink a PDF depends on what is inside it, so QuietPDF gives you three presets and lets you choose the trade-off. Lossless tidies the file’s internal structure and strips redundant metadata while keeping every pixel. Balanced downsamples images to 150 DPI at 80% quality, the best all-round saving for everyday documents. Extreme pushes images down to 90 DPI at 50% quality for the smallest possible file. Text stays sharp at every level because it is stored as vectors, not pixels.
Reduce a PDF to fit an email attachment limit
The most common reason to shrink a PDF is to email it. Gmail caps attachments at 25 MB and Outlook at around 20 MB, and a single scanned contract can blow straight past that. Drop the file in below, choose Extreme for the biggest cut (or Balanced if you want to keep more image detail), and you will usually land well under the limit. Sending a whole folder? Add them all and reduce the batch in one go.
How to reduce PDF file size
- 1
Drop your PDFs
Drag one PDF or many into the box below, or click to pick files.
- 2
Pick how small
Choose Lossless, Balanced, or Extreme depending on the size you need.
- 3
Download
Grab each smaller PDF, or download the whole set at once.
Compress your PDFs quietly
Drop one PDF or many. Your files never leave the browser tab.
Drag & Drop PDFs here
or click to browse — pick one file or many
Local Vault (Recent Compressions)
Auto-clears after 2 hours
No local history found.
Compressed PDFs land here automatically and auto-clear after 2 hours.
Frequently asked questions
How do I reduce the size of a PDF?
- To reduce the size of a PDF, drop it into QuietPDF, pick a preset (Lossless, Balanced, or Extreme), and the file is shrunk on the spot. The smaller PDF downloads straight back to you, with no uploads, no signup, and nothing to install.
How much smaller can a PDF get?
- A PDF can typically get 50–90% smaller when it is image-heavy or a scanned document, because the Balanced and Extreme presets downsample those images. Text-only PDFs are already compact, so there the savings are smaller and come from cleaning up redundant internal structure with Lossless.
How do I reduce a PDF to send it by email?
- Most mail providers cap attachments around 20–25 MB (Gmail is 25 MB, Outlook is 20 MB). Pick the Extreme preset for the biggest reduction, or Balanced if you want to keep more image detail. If you have several files, add them all and shrink the whole batch at once.
Will making the file smaller lower the quality?
- Lossless keeps every pixel; it only strips redundant metadata and tidies the file structure. Balanced (150 DPI) and Extreme (90 DPI) downsample images to save more space, but text stays crisp because it is stored as vectors, not pixels. Pick the lightest preset that hits your target size.
Can I reduce the size of several PDFs at once?
- Yes. Add as many PDFs as you like and they are processed one after another to stay gentle on your browser's memory, then you can download each one or grab the whole set at once.
Is it free, and does my file stay private?
- QuietPDF is completely free, with no signup and no watermarks. Every PDF is shrunk inside your own browser tab using WebAssembly. The file is never sent to a server, so even sensitive documents stay on your device.
Why PDFs get so big — and what actually shrinks them
A PDF’s size is almost entirely about what is inside it. Two documents with the same page count can differ by fifty times depending on their contents. Knowing what is taking up the space tells you, before you even start, how much you can expect to save.
Scanned pages and photos are usually the culprit
A page of plain, typed text is tiny — a few kilobytes. A scannedpage is a full-resolution image, often several megabytes on its own, so a 20-page scanned contract can easily weigh 40 MB or more. Photos taken on a phone and dropped into a document are the same story. This is exactly why scanned and image-heavy PDFs shrink the most: they are full of redundant pixel data that compresses dramatically. A text-only PDF is already compact, so there is simply less to remove.
What downsampling actually does
Images inside a PDF are stored at some resolution, measured in dots per inch (DPI). A scan at 300 DPI looks crisp in print but is overkill for reading on a screen or sending by email. Downsampling to 150 DPI (Balanced) or 90 DPI (Extreme) discards resolution you usually cannot see at normal viewing size — and that is where the bulk of the savings comes from. Your text is never touched: it is stored as vector outlines, not pixels, so it stays razor-sharp at every preset.
Choosing a preset by document type
The right preset depends on what your document is made of:
- Text-only documents (reports, code, typed contracts): use Lossless. There is little image data to downsample, so the win comes from cleaning up the file’s structure with zero quality change.
- Everyday mixed documents (slide decks, brochures, anything with some images): Balanced is the sweet spot — a big size cut you will not notice on screen.
- Scans and photo-heavy files you need small in a hurry: Extreme squeezes images hardest for the smallest possible file.
Hitting a target size for email
Gmail caps attachments at 25 MB and Outlook at around 20 MB, and a single scan can blow past either. A reliable approach: start with Balanced and check the result; if it is still over the limit, run the original again with Extreme. Because compression happens instantly and locally, you can try both and compare the sizes in seconds, with no uploads in between. Sending several files that only collectively exceed the limit? Shrink the whole batch at once and attach the smaller versions, or send the single largest one on its own.