Why does PDF Compressor matter?

A lighter PDF that still reads clearly. Text stays sharp; heavily compressed images may soften.

What are common pdf compressor mistakes?

Compressing scans so hard the text becomes unreadable.

🗜️

100% free · no signupRuns in your browser

PDF Compressor

Re-save PDFs with optimized object streams to shrink file size.

Best for: Getting under an email or upload size limit, speeding up sharing, or archiving scans.

Complete guide

Input

How it's calculated & sources

The PDF Compressor uses the standard method for this calculation. It runs entirely in your browser, so your inputs are never uploaded. Last reviewed June 2026.

Free & no sign-up · runs entirely in your browser. Results are estimates for general information, not professional advice — verify important decisions with a qualified expert. Last reviewed June 2026.

How it works

Re-saves the PDF with useObjectStreams enabled, which packs objects efficiently. Savings depend on the input — already-optimized PDFs may not shrink further.

Continue your journey

Where people usually head next.

📝

PDF to Word

Extract a PDF's text into an editable Word (.docx) document — in your browser.

📊

PDF to Excel

Extract a PDF's text into an Excel spreadsheet (.xlsx) — in your browser.

📊

Excel to PDF

Convert Excel spreadsheets (.xlsx) to PDF in your browser — values as a table.

✂️

Crop PDF

Trim the margins of every PDF page by a percentage — lossless, in your browser.

Complete guide

Quick answers

Short, sourced answers to the questions people (and AI assistants) ask most.

What is PDF Compressor?: A PDF compressor reduces a PDF's file size, mainly by recompressing the images embedded in it and removing redundant data. It runs in your browser.
Why does PDF Compressor matter?: A lighter PDF that still reads clearly. Text stays sharp; heavily compressed images may soften.
How is PDF Compressor calculated?: Text in a PDF is vector and already small, so the savings come from re-encoding embedded images at a lower resolution or quality and stripping unused objects. You trade some image quality for a smaller file.
What are common pdf compressor mistakes?: Compressing scans so hard the text becomes unreadable.
When should you use the PDF Compressor?: Getting under an email or upload size limit, speeding up sharing, or archiving scans.

What is the PDF Compressor?

A PDF compressor reduces a PDF's file size, mainly by recompressing the images embedded in it and removing redundant data. It runs in your browser.

How the PDF Compressor works

Text in a PDF is vector and already small, so the savings come from re-encoding embedded images at a lower resolution or quality and stripping unused objects. You trade some image quality for a smaller file.

Common mistakes to avoid

Compressing scans so hard the text becomes unreadable.
Expecting big savings on a text-only PDF — it is already small.
Compressing a digitally-signed PDF, which can invalidate the signature.

Keywords: pdf, compress, optimize.

Sources: ISO 32000 / PDF Association

Reviewed by the Free Tools Galaxy editorial team · Updated June 2026 · Calculated privately in your browser.

Frequently asked questions

Is the PDF Compressor free to use?+

Yes. Every tool on Free Tools Galaxy is 100% free, runs in your browser and requires no signup.

How accurate is the PDF Compressor?+

PDF Compressor uses the standard pdf compressor formula in double-precision arithmetic, so the same inputs always produce the same result and you can verify any figure by hand. It is an educational estimate — real-world outcomes depend on your actual rates, rules and assumptions.

Do you store my inputs?+

No. The PDF Compressor runs entirely in your browser. Nothing is uploaded or saved to a server.

Can I use the PDF Compressor on mobile?+

Yes — the interface is fully responsive and works on phones, tablets and desktops.

What are common mistakes to avoid?+

The most frequent mistake is mixing units. Double-check your inputs use a single, consistent unit before clicking Calculate.

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📝PDF to WordTop match 📊PDF to ExcelExtract a PDF's text into an Excel spreadsheet (.xlsx) — in your browser.📊Excel to PDFConvert Excel spreadsheets (.xlsx) to PDF in your browser — values as a table.✂️Crop PDFTrim the margins of every PDF page by a percentage — lossless, in your browser.🔧Repair PDFRe-save a PDF to fix minor corruption and files that will not open.📝Word to PDFConvert Word (.docx) documents to PDF in your browser — text and basic formatting.

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Reddit post

Title: I built/used this free pdf compressor — instant, no signup

Body: Re-save PDFs with optimized object streams to shrink file size. Try it: https://freetoolsgalaxy.com/tools/pdf-compressor

LinkedIn post

PDF Compressor on Free Tools Galaxy — Re-save PDFs with optimized object streams to shrink file size. https://freetoolsgalaxy.com/tools/pdf-compressor

Medium intro

# PDF Compressor — the free tool I keep coming back to

Re-save PDFs with optimized object streams to shrink file size.

Try it: https://freetoolsgalaxy.com/tools/pdf-compressor

Quora answer

The fastest way is to use a free in-browser pdf compressor: https://freetoolsgalaxy.com/tools/pdf-compressor. Re-save PDFs with optimized object streams to shrink file size.

Embed this tool anywhere

Free embed code for blogs, docs and dashboards. Every embed sends a backlink home — helping you and the galaxy grow together.

HTML iframe

Drop into any site — auto-resizes to its content height, theme-aware.

<iframe src="https://freetoolsgalaxy.com/tools/pdf-compressor?embed=1" title="PDF Compressor" loading="lazy"
  style="width:100%;height:600px;border:0;border-radius:16px;background:#0b1020"
  allow="clipboard-write"></iframe>
<script>window.addEventListener("message",function(e){if(e.data&&e.data.type==="ftg-embed-height"){document.querySelectorAll("iframe").forEach(function(f){if(f.contentWindow===e.source){f.style.height=e.data.height+"px";}});}});</script>
<p><a href="https://freetoolsgalaxy.com/tools/pdf-compressor" target="_blank" rel="noopener">Powered by PDF Compressor on Free Tools Galaxy</a></p>

Responsive wrapper

Aspect-locked container — good for blog post bodies.

<div style="position:relative;padding-bottom:75%;height:0;overflow:hidden;border-radius:16px">
  <iframe src="https://freetoolsgalaxy.com/tools/pdf-compressor?embed=1" title="PDF Compressor" loading="lazy"
    style="position:absolute;inset:0;width:100%;height:100%;border:0" allow="clipboard-write"></iframe>
</div>

WordPress / Markdown

Paste in a custom-HTML block or markdown file.

[PDF Compressor — free online tool](https://freetoolsgalaxy.com/tools/pdf-compressor)

<iframe src="https://freetoolsgalaxy.com/tools/pdf-compressor?embed=1" width="100%" height="600" frameborder="0"></iframe>

Text link-back

Minimal credit link — best for sidebars and footers.

<a href="https://freetoolsgalaxy.com/tools/pdf-compressor" target="_blank" rel="noopener">Try the free PDF Compressor</a>

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Input

How it works

Continue your journey

Complete guide

Quick answers

What is the PDF Compressor?

How the PDF Compressor works

Common mistakes to avoid

Frequently asked questions

Explore more

Popular tools

Explore other categories

Smart Autopilot

Likely next step

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Next best tool

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