Your PDF is 18 MB. The email attachment limit is 10 MB. Or the client portal won't accept files over 5 MB. Or you just need to send it without the recipient waiting 30 seconds for it to download.
Compress it in seconds, free, in your browser: Compress PDF — Free, No Upload
How to Compress a PDF
- Go to the PDF Compressor
- Click Choose File and select your PDF
- Choose your compression level — High, Medium, or Low
- Click Compress PDF
- Download the compressed file
The tool shows you the original size and compressed size side by side before you download.
How Much Can a PDF Be Compressed?
It depends entirely on what's inside the PDF:
Image-heavy PDFs — scanned documents, photo albums, brochures — compress by 50–80%. Images are the largest component of most PDFs and respond well to compression.
Text-heavy PDFs — reports, contracts, ebooks — compress by 10–30%. Text is already highly compressed in PDF format, so the savings are smaller.
Already-compressed PDFs — if the PDF was exported from a tool that already optimized it, further compression may reduce size by only 5–10%.
A scanned 20-page document at 15 MB can often be reduced to 3–5 MB. A 500-page text contract at 2 MB may only compress to 1.6 MB.
Does Compressing a PDF Reduce Quality?
At Medium compression, the difference is invisible on screen and in print for standard documents. Text remains sharp. Images show no visible degradation.
At High compression, images in the PDF are resampled at lower resolution. For documents shared digitally or printed at standard size, this is unnoticeable. For large-format printing or high-resolution graphics, use Medium instead.
Low compression applies minimal processing — file size reduction is modest but quality is fully preserved.
Is My PDF Uploaded to a Server?
No. The compression runs entirely in your browser using pdf-lib and pdfjs-dist. Your PDF never leaves your device — it is never sent to any server, never stored, and never accessible to anyone else.
This matters for PDFs containing contracts, financial records, legal documents, or personal data.
Common Reasons to Compress a PDF
Email attachments — Most email providers cap attachments at 10–25 MB. Compress large PDFs before attaching to stay within limits.
Client portals and upload forms — Many CRM tools, legal platforms, and HR systems have file size limits. A compressed PDF passes where the original fails.
Sharing via messaging apps — WhatsApp, Telegram, and similar apps have file size limits. Compressing a scanned document gets it under the threshold.
Cloud storage — Batch-compressing a folder of PDFs before uploading to Google Drive or Dropbox saves storage quota.
Faster downloads — A 3 MB PDF loads noticeably faster than a 15 MB PDF, especially on mobile connections. If the PDF is on a website or shared via a link, compress it first.
Related PDF Tools
- Merge PDF — combine multiple PDFs before compressing
- Split PDF — extract pages before compressing to target specific sections
- Rotate PDF — fix orientation before compressing
Compress your PDF now — free, no upload: PDF Compressor
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