Compressing a PDF is not about making the file tiny at any cost. You may need readable scans, clear tables, signatures, stamps, QR codes and barcodes. The right compression level depends on what happens to the file next.
How to choose compression level
| Сценарий / Scenario | Что выбрать / Choice | Почему / Why | | --- | --- | --- | | Email attachment | Medium compression | Reduces file size while usually keeping it readable. | | Portal rejects file size | Stronger compression | The file must fit the limit, then quality must be checked. | | Document scans inside | Light or medium compression | Readability of text, stamps and signatures matters more than minimum size. | | Archive file | Minimum sufficient compression | The document must remain usable for future review. |
What changes during compression
PDF size can be reduced through image optimization and removal of unnecessary technical data. Stronger compression increases the risk of blurry scans, charts and small text.
Practical rule
Do not choose maximum compression by default. Choose the smallest size that still keeps the document readable. If the portal limit is 10 MB, there is no benefit in reducing to 1 MB if stamps and tables become hard to read.
What to inspect carefully
Check pages with scans, signatures, stamps, tables, QR codes, barcodes, small text and images. These areas show compression damage first.
What to check before compression
- original file size
- target email or portal limit
- content type
- critical pages
- saved original
- final file name
Clean workflow / Рабочий процесс
1. Keep the original PDF. 2. Define the target size. 3. Start with moderate compression. 4. Open the result and check important pages. 5. If it is still too large, try stronger compression. 6. If quality is poor, return to the original.
Common mistakes / Частые ошибки
Starting with maximum compression
It can damage quality more than necessary.
Checking only the first page
Quality may differ across a large PDF.
Deleting the original
You need it if the compressed version fails review.
FAQ
Can I compress without quality loss?
Sometimes the reduction is barely visible, but it depends on the file content.
What level should I use for scans?
Usually light or medium, followed by readability checks.
What matters more: size or quality?
Portals care about limits, work documents need readability and archives need reliable reuse.
Final CTA
The best compression is not the smallest file. It is the file that fits the limit and remains useful.