Is your PDF too big to email? Photo-heavy and scanned files often hit size limits. The PDF Recompress Images tool redraws each page as a JPEG at the quality you choose. It downloads the result only if the new file is smaller.
It suits anyone with a scan, a brochure, or a slide deck full of pictures. The trade is real: pages become images, so you lose selectable text.
Table of Contents
- What the Tool Offers
- How to Use It, Step by Step
- How It Works
- Choosing a Quality Level
- A Walkthrough With Tom
- What Changes in Your File
- File Handling and Privacy
- Limitations and Assumptions
- FAQs About the PDF Recompress Images
What the Tool Offers
- An upload box labeled "Drag & drop PDF to recompress images" that accepts a click or a drop.
- A menu named "Target JPEG Compression Quality:" with three choices: Low (50%), Medium (75%), and High (90%).
- A hint under the menu: "Pages are drawn at 150 DPI, then saved as JPEG at the quality above".
- A status line that starts as "Ready" and one button, Recompress & Download PDF.
How to Use It, Step by Step
- Click the upload box, or drop one PDF on it.
- Wait for the status "PDF loaded (4,096.0 KB). Pick a quality, then recompress." Your own file size appears in the brackets.
- Pick a quality level. Medium is selected by default.
- Click Recompress & Download PDF. The status shows "Working..." and then "Recompressing page 2 of 8..."
- If the new file is smaller, your browser saves pdf-recompressed-images.pdf and the status reports the sizes.
The button stays disabled while the tool works. With no file loaded, a click shows "Please choose a PDF file first."
How It Works
The tool does not edit the pictures inside your PDF. It flattens each whole page into one new picture.
Choose PDF→Draw pages at 150 DPI→Save as JPEG→Compare sizes→Download if smaller
The pdf.js library draws each page onto a canvas. The page is saved as a JPEG at 0.5, 0.75, or 0.9 quality, based on your menu choice. The pdf-lib library then builds a new PDF with one picture per page, at the original page size.
Finally, the tool compares the byte counts of the old and new files. It downloads the new file only when it is smaller.
Choosing a Quality Level
Low (50%) gives the smallest file and the softest pictures. High (90%) keeps more detail and gives a larger file. Medium is a balanced middle choice.
Start with Medium. If the file is still too big for your limit, run it again at Low. On a photo-like test file, the 50% output came out smaller than the 90% output.
A Walkthrough With Tom
Tom has a photo brochure of 4,096.0 KB, and his email limit is 3 MB, or 3,072 KB. He picks the file and leaves the menu on Medium. He clicks the button and waits while the page counter runs.
In this illustration, the status line then reads: "Done. Size: 4,096.0 KB to 1,843.2 KB (55.0% smaller). Pages are now images. Your download has started." Your own numbers will differ, because they depend on the file.
The new size is under his limit, so Tom attaches the file. He confirms the final size with the PDF file size checker. One KB here means 1,024 bytes.
What Changes in Your File
Each page becomes a flat picture. Text, links, bookmarks, and form fields are not carried over. Document properties such as the title are also dropped.
Page count and page size stay the same. The percentage in the result line shows how much smaller the new file is, with one decimal place.
File Handling and Privacy
The pdf-lib and pdf.js libraries load from public script hosts. Your PDF is read, drawn, and rebuilt in your browser. The page contains no upload request, and the download is created on your device. The tool keeps no copy, so choose the file again each visit.
Limitations and Assumptions
- Resolution is fixed at 150 DPI. Only the JPEG quality can be changed.
- The tool flattens whole pages and does not edit embedded pictures one by one.
- Text-heavy files usually get larger, so they produce no download.
- It handles one file at a time and processes pages in your browser, so large files take a while.
- Pages longer than about 26 inches are scaled down to fit a 4,000 pixel limit.
FAQs About the PDF Recompress Images
Why did I get no download?
The status reads "No download. The recompressed file would not be smaller." A red message then lists both sizes. Try Low Quality, or keep your original.
Will small text stay readable?
Usually yes at 150 DPI, but fine print can look soft at Low. Use High for pages with small type.
Can I get selectable text back?
Not from the result directly. Run it through the OCR PDF converter to add a searchable text layer.
What other tools shrink a PDF?
The compress PDF tool targets total file size. For picture settings, see the PDF image quality optimizer and the PDF image resolution changer. All are listed in the PDF tools hub.
What does the red processing error mean?
The message reads "This PDF could not be processed. It may be encrypted, password-protected, or corrupted." Try an unlocked or repaired copy of the file.
Can I pick which pages to shrink?
No. Every page is rebuilt. Keep a copy of the original, because the tool does not change your file on disk.
This tool runs in your web browser and may not handle every PDF file, font, or browser the same way. Keep a backup of your original file. Reviewed for general accuracy by Prof. Dr. Khalil Mudassar, PhD.