To compress a PDF, select Select PDF, pick a Compression Preset such as Balanced or Strong Compression, and select Compress PDF. Each page is redrawn as a JPEG image at the size you chose and saved into a new, smaller PDF, which downloads straight away. It works best on scanned PDFs. Text in the result can't be selected.
How to compress a PDF
- Add your PDF. Drag a PDF onto the drop area or select Select PDF. Up to 8 pages are previewed, and the summary shows the original size.
- Pick a preset. Balanced is selected by default. Choose Strong Compression or Maximum Compression for a smaller file, or Higher Quality for sharper pages.
- Fine-tune if needed. Move the JPEG Quality, Render Scale or Max Page Width sliders, or switch on Grayscale Output. Est. Output and Potential Saving update as you go; the estimate comes from compressing up to three sample pages with your settings.
- Compress. Select Compress PDF. The new file downloads as
yourfile-compressed.pdf, and the summary shows its real size and how much you saved.
How this PDF compressor reduces file size
The tool renders every page to an image in your browser, compresses that image as JPEG (or PNG if you choose it), and builds a new PDF from those images. That is why it works so well on scans: a page photographed at 300 dpi or more gets resampled to a much lower resolution and recompressed.
It also has costs you should know about before you send the file:
- Text becomes part of the picture. You can't select, copy or search it in the compressed PDF.
- Links, bookmarks, fillable form fields and attachments are dropped.
- Page sizes stay the same as in the original. Render Scale and Max Page Width only set the image resolution, so a higher scale gives sharper pages and a bigger file.
- A digital PDF made from Word or a web page is often already small. Turning its text into images can leave it the same size or even larger.
If you need searchable text, keep the original or run the compressed copy through an OCR app. For text-only PDFs that are too big, removing pages you don't need with the PDF splitter usually helps more.
Compression presets compared
Render Scale sets resolution: 1.00x means 72 pixels per inch of the original page. Max Page Width only matters for pages wider than normal paper, such as drawings and posters.
| Preset | JPEG Quality | Render Scale | Max Page Width | Color |
|---|---|---|---|---|
| Higher Quality | 0.84 | 1.45x (about 104 ppi) | 1800 px | Color |
| Balanced (default) | 0.68 | 1.15x (about 83 ppi) | 1400 px | Color |
| Strong Compression | 0.52 | 1.00x (72 ppi) | 1200 px | Color |
| Maximum Compression | 0.38 | 0.85x (about 61 ppi) | 1000 px | Grayscale |
Body text stays readable at Balanced on a screen. Small print, footnotes and signatures look soft at Maximum Compression, so check the preview at 100% before you send anything important. Changing any slider switches the preset to Custom.
How to compress a PDF to 1MB or for email
Know the limit you're aiming for before you change any PDF compress settings. Gmail's attachment limit is 25 MB, and the Outlook desktop app caps Outlook.com and other internet accounts at 20 MB. Many job and visa portals ask for 1 MB or 2 MB per file. To hit a target like that:
- Start with Balanced and read Est. Output in the summary. It's worked out from a few sample pages compressed with your settings, so it's usually close, but it isn't a promise.
- If it's still too big, switch to Strong Compression, then Maximum Compression.
- Turn on Grayscale Output for black and white documents. It cuts color data without hurting legibility.
- Leave out pages you don't need by typing a Page Range such as
1-5,8. Only those pages go into the new file.
After you select Compress PDF, the summary shows the real output size. If it says "No major reduction", the PDF was probably text-based to begin with, and a note suggests keeping your original. For an image you want to attach instead of a PDF, the image compressor for 1 MB is a better fit.
Other ways to reduce PDF file size
On a Mac, Preview has a built-in option that keeps text intact: open the PDF, choose File › Export, set Quartz Filter to Reduce File Size and save. Its results vary and image quality can drop sharply.
If the PDF is a scan you made yourself, scanning again at 150 to 200 dpi in grayscale often produces a small file from the start. And if the PDF came from Word or Google Docs, compressing the pictures before export shrinks the PDF while keeping text selectable.
Frequently asked questions
How do I compress a PDF for free?
Load the PDF into the compressor at the top of this page, choose a preset and select Compress PDF. It's free, there's no sign-up, and no watermark is added.
Will compressing a PDF make the text unselectable?
Yes. This compressor turns each page into an image, so the text in the output can't be selected, copied or searched. Keep your original file if you need the text.
Why didn't my PDF get smaller?
Digital PDFs with mostly text are stored very efficiently, and turning their pages into images can make them bigger. The tool works best on scanned and photo-heavy PDFs.
Can I compress a PDF to an exact size like 1 MB?
Not to an exact size. Use the Est. Output figure as a guide, try Strong or Maximum Compression and grayscale, and remove pages you don't need until the result fits.
Can I compress a password-protected PDF?
No. The tool can't open a PDF that needs a password. Remove the password with the PDF password remover first, using the password you know.
Is it safe to compress confidential PDFs here?
Yes. The PDF is read and compressed in your browser, and the new file is created on your device. Nothing is sent to ToolzyLab or anyone else.