FunnyTools 繁中 Español Français

PDF Compressor

PDF Tools

Try three compression modes while preserving text and vector content when possible.

PDF Compressor offers Lossless, Balanced (default), and Strong modes. It prioritizes rewriting PDF structure while preserving text and vector content when possible. Raster images may be recompressed, and digitally signed PDFs are rejected to avoid invalidating signatures.

Tool area

These tools use the FunnyTools Conversion API; the files you choose are sent to the API for processing.

Digitally signed PDFs are rejected to avoid invalidating signatures.

Original size—
Output size—
Size change—

No PDF selected

Cancel stops the browser from waiting; it does not guarantee that server CPU work already started stops immediately.

What this tool can do

  • Lossless, Balanced (default), and Strong modes
  • Preserve text and vectors when possible
  • Recompress raster images when appropriate
  • Reject digitally signed PDFs before processing

Compression that keeps text and vectors in view

The tool does not make full-page JPEG rendering the default compression method. Text and vectors are preserved when possible, while raster images may be recompressed; if the output is not smaller, the safer result is returned.

Digitally signed PDFs are rejected because rewriting them can invalidate the signature.

These tools use the FunnyTools Conversion API; the files you choose are sent to the API for processing.

How to use

  1. Choose a PDF.
  2. Select a mode; Balanced is the default starting point.
  3. Download, compare file sizes, and inspect text, images, and signature requirements.

Use cases

  • Reduce a PDF attachment for email or a form upload.
  • Prepare a smaller copy of a report with text and images.
  • Test compression strength before sharing a document.

Who is it for

  • Users testing structural optimization on unoptimized PDFs
  • Document managers comparing file size before and after rewriting
  • Professionals who need files to remain in the browser

Real examples

Test a PDF created by older software

Keep the original, rewrite the PDF structure, and compare sizes. Even when output is smaller, reopen it and inspect fonts, pages, forms, and attachments. Keep the original whenever the result is not smaller.

Decide whether image compression is actually needed

A scan-heavy PDF may not shrink because image streams dominate its size. That requires a separate image-resolution decision; this tool deliberately avoids resampling images and therefore cannot promise a compression ratio.

Good to know

  • A smaller output does not imply lower visual quality because this tool primarily reorganizes objects and streams.
  • Encryption, signatures, complex forms, and unusual attachments may not survive rewriting and require careful verification.
  • Do not replace legal, signed, or archival originals until the rewritten file has been fully compared.

FAQ

Which mode should I try first?
Balanced is the default starting point. Try Lossless when text and vectors need the most conservative handling; Strong may treat images more aggressively.
Does it render every page to JPEG?
No. Full-page JPEG rendering is not the default. Text and vectors are preserved when possible, while raster images may be recompressed.
Why are signed PDFs rejected?
Rewriting a file can invalidate its signature, so digitally signed PDFs are rejected. Keep the original and use an appropriate signed-document workflow.

Related tools

Merge PDFCombine multiple PDFs in your chosen order locally in the browser.Tool🔒 Local onlyUse NowNewest
PDF Page ReorderRearrange PDF pages locally in your browser.Tool🔒 Local onlyUse NowNewest
Split PDFSplit one PDF into single pages or custom page-range files.Tool🔒 Local onlyUse NowNewest
Images to PDFTurn ordered JPG or PNG images into one local PDF download.Tool🔒 Local onlyUse NowNewest
Rotate PDFRotate every page or selected page ranges by 90, 180, or 270 degrees.Tool🔒 Local onlyUse NowNewest
Delete PDF PagesRemove selected pages from a PDF and download the remaining document.Tool🔒 Local onlyUse NowNewest
Merge PDFs Without Uploading Them Anywhere Modern browsers can rebuild PDFs on your own machine, so source files are not uploaded for the merge. If you choose email delivery, the generated file follows the page's Brevo disclosure. The trick is telling local-processing tools apart from upload-based ones, then checking the output properly. A4 vs US Letter: Print Worksheets Without Cutoffs A4 (210×297 mm) is 6 mm narrower and 18 mm taller than Letter (215.9×279.4 mm). Cross-printing works fine if you pick the right scaling option — and quietly destroys layouts if you pick the wrong one. Photos to PDF on Your Phone — No App Needed Open an images-to-PDF tool in the phone browser, select photos, set the order, pick a paper size, export — four steps, files never leave the device. Eighty percent of the quality is decided at shooting time. Merged PDF Page Size and Orientation Guide Merging places pages in one file; it does not automatically make every page the same paper size. Decide whether the file is for reading, printing, or archiving before changing original dimensions.
Student Report Toolkit This workflow helps students check report length, image size, PDF pages, QR codes, and text formatting before submitting homework, presentations, or research reports. Office Document Toolkit This workflow helps office workers handle everyday document tasks: organize PDFs, compress files, estimate dates and business days, create QR codes, and inspect JSON data.

Privacy & temporary processing

Files are uploaded to the FunnyTools Conversion API for conversion and processed during the request; do not upload unnecessary personal or confidential data.

Trust & usage note

This is a server-side conversion tool; files you choose are sent to the FunnyTools Conversion API for temporary processing. Do not upload unnecessary personal or confidential data, and inspect the result after downloading.

Last updated:

Get updates

New tools and practical tips, straight to your inbox. No spam, unsubscribe anytime.