Last updated: October 2026
How to compress a PDF
- Choose your PDF — it stays in your browser and is never uploaded.
- Pick a resolution (150 DPI for high quality, 100 DPI balanced, 72 DPI smallest) and a JPEG quality.
- Click Compress PDF.
- Compare the before/after sizes, then download the smaller file.
Why compress a PDF here?
Fit the attachment limit. Email inboxes and upload forms cap attachments — a 25 MB scan becomes a few MB. See the real saving. The tool shows the before and after size and the percentage saved, so you know exactly what you got. Honest trade-off. This tool re-renders each page as an image at the resolution you choose, which is what actually shrinks image-heavy PDFs in a browser. The trade-off is stated plainly: output pages are images, so text is no longer selectable. If you need selectable text, keep the original. To cut pages instead of quality, delete PDF pages you don't need, or extract PDF pages into a smaller file.
What this compressor does — and does not do
Short answer: each page is re-rendered as an image at the resolution and JPEG quality you choose, then rebuilt into a new PDF. That is what genuinely shrinks image-heavy PDFs in a browser. It does NOT do text-preserving compression — output pages are images, so text is no longer selectable or searchable. We don't claim otherwise. For text-heavy PDFs that are already lean, the output can even be larger; the tool tells you so instead of hiding it.
Which setting should I pick?
For scans you still need to read and print, 150 DPI at 70-80% quality stays sharp. For emailing a scan someone just needs to read on screen, 100 DPI at 60% is the sweet spot. For the smallest possible file where rough legibility is enough, 72 DPI at 40-50% wins. If the output is still too big, drop the DPI first — resolution moves file size more than the quality slider.
Frequently asked questions
Is my PDF uploaded anywhere?
No. The entire compression runs in your browser with JavaScript — your PDF never leaves your device, which makes this safe for sensitive documents.
Will the text still be selectable after compression?
No. Output pages are images, so text is no longer selectable or searchable. That is the honest trade-off of image-based compression — keep your original if you need selectable text.
How much smaller will my PDF get?
It depends on the input. Scanned and image-heavy PDFs often shrink by half or more. Text-heavy PDFs that are already lean may barely shrink, or even grow — the tool shows the before/after sizes and warns you if the output is larger.
What resolution should I choose?
150 DPI keeps print quality for scans you need to read closely. 100 DPI is the balanced choice for screen reading and email. 72 DPI gives the smallest file when rough legibility is enough.
What does the JPEG quality slider do?
It controls how aggressively each rendered page image is compressed. Lower quality means a smaller file with more visible artifacts; higher quality keeps pages crisper at a larger size.
Can I compress a password-protected PDF?
No. Password-protected PDFs can't be opened in the browser, so they can't be compressed here. Remove the password in your PDF reader first, then compress.
Will compression change my page size?
No. Every output page keeps the original page dimensions — only the image resolution inside changes.
Can I compress a PDF on my phone?
Yes. The compressor works on phone and desktop browsers. Large scans take a little longer on phones since all the work happens on your device.
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