The concern with PDF compression is always the same: will my document look worse afterwards? The answer depends on which compression level you choose. Here's how to get the maximum size reduction with minimal quality impact.
Basic compression optimises metadata, stream objects, and font data without touching image quality — typically 5–20% reduction with zero visual change. Good compression applies moderate JPEG re-encoding to embedded images — typically 30–60% reduction with minimal visible difference on screen. Strong compression aggressively re-encodes all images — typically 60–90% reduction with some image softness visible at close inspection.
For documents that will be printed or reviewed closely (contracts, academic papers, high-resolution reports), use Basic. For documents being emailed or uploaded to web forms, use Good. For archiving, sharing over messaging apps, or uploading to systems with strict size limits, use Strong.
Tip: Test with Good first — it handles 80% of cases. If the result is still too large, switch to Strong.
Go to pdfeditor.onl/compress-pdf, upload your PDF, select your compression level, click Compress Now, and compare the before and after file sizes shown on screen. Download the result.
No. Basic compression only removes redundant internal metadata and optimises object streams — the rendered output is visually identical to the original.
Text in PDFs is vector-based, not image-based. It remains sharp at any zoom level regardless of compression level. Only embedded raster images are affected by JPEG re-encoding.
Yes, but diminishing returns apply quickly. If you've already compressed with Strong, a second compression will produce minimal additional reduction.