pdf compress

PDF Compress

Try to reduce PDF size locally. Results depend on the document.

Before you compress

This tool attempts to reduce file size by recompressing supported RGB JPEG images embedded in the original PDF. It does not convert entire pages into images.

The selected compression level controls JPEG quality and the maximum dimensions of supported images. Images with unsupported formats, color settings, or masks are left unchanged.

Not every PDF can be reduced. If the generated file is not smaller, the download remains your unchanged original. Keep your source file and review page appearance, text, links, and forms before using the result. PDFs with detected signature fields are not supported.

Compress PDF Files Online

Vamriko PDF Compressor attempts to reduce file size by recompressing supported JPEG images within the original document and saving the PDF with object-stream compression. Processing runs locally in your browser without converting entire pages into images. If the result is not smaller, the original file is offered unchanged.

PDF compression can be useful for email attachments, document sharing, storage, and workflows where smaller files are easier to handle.

How to Compress a PDF

Select Your PDF Choose the PDF file you want to reduce in size.

Start Compression Run the compressor and let the browser process the document.

Save the Result Download the processed PDF and compare its size with the original.

PDF Compressor FAQ

Why should I compress a PDF?

A smaller PDF can be easier to email, upload, share, and store, especially when the original document is large.

Does compression replace my original PDF?

No. The processed document is created separately, so your original PDF remains available.

Will every PDF become much smaller?

Not necessarily. The amount of size reduction depends on the contents and structure of the source PDF.

Can I use the compressed PDF for sharing?

Yes. A smaller PDF can be more convenient for common sharing and upload workflows.

Are my files uploaded to Vamriko?

The compression code processes your PDF locally in your browser without uploading its contents for compression. The page also loads analytics, advertising and supporting resources.

What the compression levels change

Low uses a JPEG quality setting of 0.85 and a maximum image side of 3200 pixels. Medium uses 0.70 and 2400 pixels. High uses 0.50 and 1600 pixels. These limits do not enlarge smaller images. All levels may reduce image quality; Low is not a lossless mode.

The JPEG quality setting is an encoding parameter, not a guaranteed percentage of retained quality. High is more aggressive, but it does not guarantee the smallest file for every document. A replacement image is used only when its encoded bytes are smaller than the original image stream.

Why some images are left unchanged

This version targets 8-bit DeviceRGB JPEG image streams using a single DCTDecode filter. Images with masks or other excluded dictionary settings are skipped. It also skips image streams below 16384 bytes, images above 24 million pixels, and images that cannot be decoded with matching dimensions.

Text-heavy PDFs, already optimized documents and PDFs containing unsupported image formats may show little or no reduction. Saving the document can also change its overall size. If the candidate PDF is not smaller, the download contains the unchanged original bytes.

Controls are locked while processing. Detected signature fields or signature objects cause the operation to stop; this is not a tool for verifying signatures. Keep your original and review the resulting pages, text, links and forms before sharing.