How to Compress a PDF Online for Free (3 Levels, Real Example)
Email servers reject big attachments, upload forms have size limits and a heavy PDF is slow to open on a phone. Compressing the file solves all three. This guide shows how to compress a PDF online with ToolTiny in a few clicks, what the three compression levels mean, and what a real result looks like: a 7.47 MB brochure that became 598.7 KB.
Why PDF Files Become Large
- High-resolution images. Photos, scans and screenshots are the most common cause, because every image is stored at full resolution.
- Scanned pages. A scanned document is a stack of page pictures, so it is much heavier than the same text typed.
- Embedded fonts and extra data. Fonts, metadata and leftovers from editing add weight.
- Many pages. Reports, manuals and catalogs grow with every page.
Compression mainly reduces the size of the images inside the PDF and removes unneeded data. That is why image-heavy files shrink a lot and text-only files shrink little.
Watch the Whole Process
The recording opens the tool, uploads a 7.47 MB PDF, compresses it with the Recommended level and compares the file sizes.
How to Compress a PDF, Step by Step
-
Open Compress PDF
In the top bar open PDF Tools and choose Compress PDF, or go to tooltiny.com/compress-pdf.html.
PDF Tools → Compress PDF -
Find the upload box
The page is titled Compress PDF Free: Reduce File Size Online, No Sign-Up. Click the Select a PDF file box, or drag and drop your PDF into it. The Compress PDF button stays grey until you add a file.
Select a PDF file -
Choose your PDF
Pick the file from your computer. Our example is
sample-compress-pdf.pdf, a 5-page brochure full of images.
sample-compress-pdf.pdf, 7.47 MB -
Look at the three levels
The tool shows the file name and Original Size: 7.47 MB, then three levels with an estimate for each: Extreme 2.62 MB (-65%), Recommended 4.48 MB (-40%) and Less Compression 6.35 MB (-15%).
Estimates for each level -
Select a level and click Compress PDF
We kept Recommended Compression (good quality, good compression) and clicked the pink Compress PDF button.
Recommended + Compress PDF -
Wait for the upload and compression
A progress bar shows Uploading file to server and the percentage. Do not close the tab until it finishes.
Uploading and compressing -
Download the compressed PDF
PDF Compressed Successfully! shows Original 7.47 MB, New Size 598.7 KB and Saved 92%. Click Download Compressed PDF. Use Compress Another PDF for the next file.
7.47 MB to 598.7 KB -
Compare the files
In the folder, the original is about 7,655 KB and
sample-compress-pdf_compressed.pdfis about 598 KB. The original is not changed. Open the new file and check the pages before sending it.
Original vs compressed
Which Compression Level Should You Choose?
| Level | Estimate for our 7.47 MB file | Best for |
|---|---|---|
| Extreme Compression | 2.62 MB (-65%) | Email attachments and upload forms with a strict size limit. Lower quality. |
| Recommended Compression | 4.48 MB (-40%) | Most files: good quality and good compression, a balanced choice. |
| Less Compression | 6.35 MB (-15%) | PDFs you will print, where image quality matters most. |
If you are not sure, start with Recommended. If the result is still too large, run the compressed file again with Extreme, or compare the result with the original and decide whether the quality is acceptable.
What We Actually Got
The estimates are shown before you compress, and the real size depends on the content. Our sample is a synthetic, image-heavy brochure, so it compressed far better than the Recommended estimate: 7.47 MB became 598.7 KB, a 92% saving. Do not expect that number for every file. A typical business PDF with a few images shrinks less, and a text-only PDF is already small.
- Original: sample-compress-pdf.pdf, 7.47 MB (about 7,655 KB in Explorer)
- Compressed: sample-compress-pdf_compressed.pdf, 598.7 KB
- The original is untouched. The tool gives you a new file.
Tips to Keep the PDF Readable
- Always keep the original. Compression is not reversible. Store the full-quality file and send the compressed copy.
- Check the pages. Zoom into photos, small text and signatures before you send the file.
- Pick the level by purpose. Extreme for email, Recommended for everyday sharing, Less Compression for printing.
- Still too big? Split the file with Split PDF and send it in parts, or remove pages you do not need.
- Scans are the heaviest. Scan at a reasonable resolution (for example 150 to 200 dpi for reading) instead of the maximum.
- Need an editable copy? Convert the PDF with PDF to Word.
- Mind confidentiality. Files are uploaded for processing and deleted afterwards. Do not upload documents you are not allowed to share.
Choose a compression level and download the result. Free, no sign-up.