PDF File Compressor Online Free

Use this free PDF Compressor to shrink the file size of your PDF documents — right in your browser. Drag in your files, choose a compression level, and download smaller PDFs in seconds. Nothing is ever uploaded to a server.

Free Tool

PDF Compressor

Compress PDF files online — free, unlimited, and 100% private

Upload Your PDFs

Drag & drop PDF files here, or click to browse

PDF files only · multiple files at once · nothing leaves your device

By Target File Size

By Compression Level

Compression QualityLower quality = smaller file size. 60–75 is a good balance for most documents.

%

Smaller fileHigher quality

Compressing redraws each page as an optimized image, so text will no longer be selectable or searchable in the output file. Use a higher quality to keep pages sharp, or the Target File Size mode below for finer control.

Target File SizeWe'll automatically try compression levels to get as close as possible to this size, per file. Works best for image-heavy or scanned PDFs — text-heavy documents may need a larger target to stay legible.

KBMB

Convert to grayscale (extra savings for scanned or text-only documents)

100% private — compression happens in your browser, PDFs are never uploaded anywhere.

Add PDFs above, choose your settings, then hit Compress.

Results

No PDFs yet

Compressed files and download links will appear here

Compressing PDFs…

This runs in your browser — please keep this tab open. Larger or multi-page files can take a little while.

Total Space Saved

Original Size

Compressed Size

Space Saved

Files Processed

How to Use This PDF Compressor

• Add your PDFs. Drag and drop them into the box, or click it to browse your device. You can add multiple files at once.
• Pick a compression level. Choose Low, Recommended, High, or Extreme, or fine-tune the exact quality percentage yourself.
• Or target an exact size. Switch to By Target File Size and enter a size in KB or MB — the tool searches for the closest quality that fits, per file.
• Optionally convert to grayscale. This squeezes extra savings out of scanned or text-only documents that don't need color.
• Compress and download. Click Compress PDFs, then download files one by one or grab them all as a single ZIP. Downloaded files are automatically renamed to include their new size, e.g. report-482KB.pdf, so you can tell them apart from the originals at a glance.

How It Works

This tool runs entirely inside your web browser. It uses a PDF rendering engine to redraw each page onto an HTML5 Canvas at a resolution and quality level based on your settings, then re-encodes that page as an optimized image and reassembles all the pages into a brand-new, smaller PDF. Everything happens locally — your documents are never sent to a server, which also means there's no upload wait and no file-size limit imposed by a backend.

Why Compress Your PDFs?

• Easier sharing. Stay under email attachment limits and upload limits on job portals, forms, and file-sharing tools.
• Faster uploads and downloads. Smaller PDFs move faster over slow connections and load quicker in the browser.
• Save storage space. Compressed documents take up far less room on your device or cloud storage.
• Cleaner archives. Shrinking scanned documents and reports makes long-term storage and backups more manageable.

Tips for the Best Results

• Start with Recommended. It balances file size and readability well for most reports, scans, and forms.
• Use grayscale for scanned text. If a document doesn't need color, converting it to grayscale can meaningfully shrink the file further.
• Reach for a target size when you have a hard limit — for example, a 5MB email attachment cap or a portal's upload limit.
• Keep a copy of the original if you'll ever need to select, search, or copy text from the document, since compression converts pages into images.

Frequently Asked Questions

Is this PDF compressor really free?

Yes. It's completely free to use, with no sign-up, no watermark, and no limit on how many times you can use it.

Are my PDFs uploaded to a server?

No. All compression happens locally in your browser using JavaScript, the HTML5 Canvas API, and open-source PDF libraries. Your files never leave your device, which makes this tool safe for private or sensitive documents.

Will compressing my PDF reduce its quality?

Yes, to some degree. This tool shrinks file size by redrawing each page as an optimized image, so higher compression does make text and graphics look softer, though it's often barely noticeable at Low or Recommended settings. Choose a higher quality if the document will be printed or read closely.

Will I still be able to select or search text in the compressed PDF?

No. Because compression converts each page into an image, the output file is no longer text-searchable and text can't be selected or copied. Keep the original file if you need those features, and only share the compressed copy for viewing or printing.

Does this work with scanned PDFs and PDFs with forms or links?

It works with any standard, non-password-protected PDF, including scans. Since compression rasterizes each page, interactive elements like fillable form fields, clickable links, and bookmarks won't carry over to the compressed file.

Can I compress password-protected PDFs?

Not currently. Password-protected or encrypted PDFs can't be read in the browser for compression; remove the password first using a PDF editor, then compress the unlocked file.

Is there a limit on file size or number of PDFs?

You can compress up to 12 PDFs at a time, each up to 50MB, all in one batch. This is a practical limit to keep your browser responsive rather than a paywall.

Does this work on mobile phones?

Yes, the tool is fully responsive and works on modern mobile browsers, though compressing large or multi-page PDFs will be faster on a desktop or laptop.