Estimate file size reduction before compressing your PDFs
This is an estimate based on our own tests of the RapidTools compressor with one PDF of this type. Your file will be different: how much it shrinks depends on its images.
This calculator estimates how much smaller a PDF gets with the free RapidTools Compress PDF tool. It uses real results: we compressed three test PDFs (one with photos, one scanned, one text-only) on each level and measured the new size. Your own file will be different, so treat the result as an estimate, not a promise.
The compressor shrinks only the images inside a PDF. Each image is resized so its longest side is at most 2,500 pixels (High quality), 1,700 pixels (Medium) or 1,100 pixels (Maximum), and saved as a JPEG. Text, fonts and vector drawings are never changed, so text stays sharp and searchable at every level. That is why PDFs with photos or scans shrink a lot, while text-only PDFs barely change.
| Type of PDF | High quality | Medium | Maximum |
|---|---|---|---|
| Photo-heavy 15.58 MB test PDF |
90% smaller (1.51 MB) |
97% smaller (553 KB) |
98% smaller (249 KB) |
| Scanned 8.77 MB test PDF |
54% smaller (4.04 MB) |
78% smaller (1.95 MB) |
92% smaller (747 KB) |
| Text-only 16.5 KB test PDF |
22% smaller (12.9 KB) |
22% smaller (12.9 KB) |
22% smaller (12.9 KB) |
These are typical results that vary by file. A PDF whose images were already compressed shrinks less. A PDF that mixes text and photos usually lands between the text-only and photo-heavy results. Some images, such as CMYK images, are left unchanged because they cannot be safely recompressed in the browser.
Original: 40 MB scanned contract (Scanned)
Estimate on Medium: about 8.9 MB (about 78% smaller)
Result: likely to fit under the 10 MB target that arrives safely almost anywhere.
Original: 15.58 MB report with photos (Photo-heavy)
Measured on Medium: 553 KB (97% smaller)
Result: small enough for almost any email or upload form, with text still sharp.
Original: 12 MB text-only PDF (Text-only)
Estimate on any level: about 9.4 MB (about 22% smaller)
Result: compressing helps only a little. If you need it much smaller, split it with Split PDF instead.
It gives an estimate, not a guarantee. The figures come from our own tests of the RapidTools compressor with one PDF of each type: a PDF with photos became 90 to 98 percent smaller, a scanned PDF 54 to 92 percent smaller depending on the level, and a text-only PDF about 22 percent smaller. Your file will be different, because the result depends on its images.
Mostly its images. The compressor shrinks only images, so PDFs with photos or scanned pages shrink the most, and text-only PDFs barely change. PDFs whose images were already compressed shrink less, and some images, such as CMYK images, are left unchanged.
Text never loses quality, because it is never changed. Images are different: any real size reduction on images means some small loss. On High quality most people cannot see it at normal viewing size.
In our tests, a PDF with photos became about 90 percent smaller on High quality, 97 percent on Medium and 98 percent on Maximum. A scanned PDF became about 54, 78 and 92 percent smaller. A text-only PDF became about 22 percent smaller on every level. These are typical results that vary by file.
It helps you set realistic expectations and choose a level before you start: for example, whether a scanned PDF is likely to fit under an email or upload limit on Medium, or whether a text-only PDF needs to be split instead.
Photo-heavy PDFs are mostly photos or graphics, such as brochures or image-rich reports. Scanned PDFs are pages scanned or photographed from paper. Text-only PDFs were created from a word processor and contain little or no images. If your PDF mixes text and photos, the real result is usually between the text-only and photo-heavy estimates.
High quality resizes images to at most 2,500 pixels and keeps them sharp. Medium resizes them to at most 1,700 pixels, a good balance for email and uploads. Maximum resizes them to at most 1,100 pixels for the smallest file, with lower image quality. Text is never changed on any level.
Yes, as a rough guide. Estimate one typical file of each type in your batch and multiply by the number of files. Then compress one sample file with the real tool and compare, because results vary by file.
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