PDF Compressor online

What PDF Compressor does

PDF Compressor makes a PDF file smaller so it fits email attachment limits, upload forms and messaging apps. Large PDFs are usually large because of the photos and scanned pages inside them, so that is where the savings come from.

The tool decodes each large image in the document, scales it down if it is bigger than the chosen level allows, and encodes it again as JPEG with MozJPEG. The new image is used only if it is smaller than the old one. Then qpdf rewrites the file structure with maximum lossless compression. Text, fonts and vector graphics are not changed, so text stays selectable.

How to use PDF Compressor

1. Drop the files you want to make smaller.
2. Choose a compression level, or keep the recommended setting.
3. Click Compress and compare the old and new file sizes.
4. Download the smaller files.

When to use PDF Compressor

• Shrink a scanned contract or lease so it fits under the attachment size limit of your email service.
• Reduce a job application PDF with photos or certificates so an online portal with a small upload limit accepts it.
• Make a product catalog or portfolio full of photos lighter so clients can open it quickly on a phone.
• Compress scanned invoices and receipts before archiving them, to save space in cloud storage or an accounting system.

Settings explained

Light (best quality)

Keeps images up to 2400 pixels on the longest side at JPEG quality 80. For a full-page A4 scan that is about 200 DPI, which still prints well. Choose it when the file will be printed.

Recommended

The default. Limits images to 1700 pixels at quality 65, about 145 DPI for a full A4 page. Scanned text stays readable on screen and in normal office prints, and most files shrink noticeably.

Strong (smallest file)

Limits images to 1100 pixels at quality 45, about 95 DPI for a full A4 page. It suits reading on a screen or sending by chat, but small print in scans may become hard to read.

Which compression level to choose

Low keeps images up to 2,400 pixels at high JPEG quality, which suits printing. Medium (1,700 pixels) is the best balance for email and uploads. High (1,100 pixels) gives the smallest file and is fine for reading on screen.

Text, vector graphics and fonts are not touched, so they stay sharp at every level.

What is PDF?

PDF (Portable Document Format) is a document format introduced by Adobe in 1993. Files use the .pdf extension.

PDF was created by Adobe to show documents the same way on any device and printer. A PDF file describes pages with text, fonts, vector graphics and images at fixed positions. It became an open ISO standard in 2008, and there are special variants such as PDF/A for archiving and PDF/X for printing.

PDF is the right choice for documents that must look the same everywhere, such as contracts, invoices, forms, manuals, reports and files for printing. It also supports digital signatures, fillable forms, comments and password protection.

PDF is hard to edit, because text is stored as positioned pieces, not as flowing paragraphs. Converting a PDF to Word may change the layout. Scanned PDFs contain pictures of text, not real text, unless OCR has been applied.

All major web browsers open PDF files directly. Windows, macOS, iOS and most Android phones include a PDF viewer, and Adobe Acrobat Reader and many free apps can view, annotate and fill PDF forms on all platforms.

Why use FansBond PDF Compressor

Most online converters upload your files to their servers. FansBond PDF Compressor does the work inside your browser instead, using WebAssembly and modern browser APIs. Your files stay on your device, which is safer for private photos, contracts and unreleased work, and it is often faster because nothing has to upload or download.

There are no queues, no watermarks and no account. Once the page has loaded, the tool keeps working even on a slow connection.

Tips for the best result

• If the result is not smaller than your file, you get your original file back unchanged. It keeps its original file name, so you can tell it apart from a compressed copy.
• Start with Recommended and open the result before you send it. If small text in a scan looks blurry, compress the original again with Light (best quality).
• Always compress the original file, not a copy that was already compressed. Each JPEG pass loses some detail, and a second pass rarely saves much more space.
• PDFs exported from Word or other text documents are usually small already. If such a file is large, it probably contains big photos, which this tool can shrink.

How PDF Compressor works in your browser

The compressor looks at every image inside the PDF, decodes it, scales down images that are larger than needed and encodes them again at the quality level you chose. Text, fonts and vector drawings are left untouched.

After the images are replaced, qpdf rewrites the file structure with compressed object streams. If the result is not smaller than the original, you get the original back, so the tool never makes a file bigger.

Privacy and security

Most online converters upload your files to a server, process them there and keep a copy for some time. PDF Compressor works differently: the code is downloaded to your browser once, and your files are read and written only on your device.

You can check this yourself: after the page has loaded, turn off your internet connection and the tool still works. This makes it safe for contracts, IDs, medical records, private photos and unreleased work.