What is compress pdf?
PDFora compresses a PDF by rendering each page inside your browser, converting the rendered page to a JPEG image at the selected quality level, and rebuilding a new PDF from those page images. This can reduce image-heavy PDFs, but it also rasterizes page content, so selectable text, links, forms, annotations, signatures, and vector detail may be flattened or no longer behave like the original. If the rebuilt PDF is not smaller than the source, PDFora keeps the original file data instead.
How to use Compress PDF
- 1
Choose the PDF you want to reduce.
- 2
Select Light, Balanced, or Strong compression.
- 3
Start processing and keep the tab open while PDFora renders and compresses the pages locally in your browser.
- 4
Download the new compressed PDF and review it before replacing your original.
Why use this tool?
A smaller PDF can be easier to email, upload to application portals, share over slower connections, and keep within document-size limits. PDFora creates a new output file so your original remains unchanged on your device.
How PDFora works
After you select the PDF and compression option, the browser performs the supported optimization work and prepares a new compressed copy on your device. Document contents are not sent to PDFora servers.
Common ways to use Compress PDF
- Email attachments that exceed mailbox limits
- Application or document portals with file-size limits
- Image-heavy scanned records and reports
- Archiving copies that do not need maximum image resolution
Tips for better results
- Use Balanced first for a practical size-quality tradeoff.
- Try Strong for scanned or image-heavy PDFs when a smaller file matters more than image detail.
- If the rebuilt PDF is not smaller, PDFora keeps the original file data instead of giving you a larger result.
- Always check small text, diagrams, and images in the downloaded copy before important submission.
Frequently asked questions
Will PDF compression change my original file?
No. PDFora generates a separate result and does not modify the original file stored on your device.
Why did my PDF shrink only a little?
PDFora compares the rebuilt compressed PDF with the source. If the image-based result is not smaller, the original file data is kept, so some PDFs may show little or no size reduction.
What is the file size limit?
The current limit is 50 MB per selected PDF file.
Are password-protected PDFs supported?
Password-protected PDFs are rejected in this version because the service does not ask for or store PDF passwords.
Why compression results differ from one PDF to another
A PDF made mostly from text and vector shapes behaves differently from a scanned document made from full-page photographs. Image-heavy files usually offer more room for size reduction, but stronger image compression can make small text, signatures, diagrams, or screenshots look softer. A file that already contains optimized images may not shrink very much without a visible quality tradeoff.
Before sending an important compressed document, compare several representative pages at normal reading zoom and at a closer zoom. Check small text, thin lines, logos, photos, and any page that contains a scan. If the result is being uploaded to an application portal, also confirm that the final file is below the portal limit rather than repeatedly compressing it without a target.
When not to compress again
Repeatedly compressing the same already-compressed PDF can create unnecessary quality loss while saving very little additional space. Keep the original file, make one working copy, and compress from the original when you need a different size target. If the document must remain suitable for printing, prioritize readability and image detail over the smallest possible number of megabytes.