Reduce PDF size for email and uploads

How it works in FileLume

• Safe re-save loads the PDF with pdf-lib and saves it again without rasterizing pages, which preserves selectable text but often produces limited savings.
• Scanned/image-heavy mode uses PDF.js to render each page, converts the canvas to JPEG, and embeds the result into a new PDF.
• If raster compression produces a file more than 5% larger, the current implementation returns the original bytes instead.

Best for

• Reducing scanned reports, image-heavy forms, receipts, and camera-created PDFs.
• Trying a safe cleanup on PDFs that must keep selectable text.
• Preparing a sharing copy for email or an upload portal.

Format and quality guidance

• Use Safe re-save first for text/vector PDFs and when selectable text matters.
• Use scanned/image-heavy mode only when the pages are mostly images and some quality loss is acceptable.
• Lower raster scale and JPEG quality reduce size but also reduce page clarity.

Trade-offs to expect

• Safe re-save may make almost no difference when the PDF is already optimized.
• Raster mode can make text non-selectable, soften small text, and remove vector sharpness.
• Some PDFs become larger after rasterization; FileLume protects against returning a result more than 5% larger.

Limitations

• Browser compression cannot match a full desktop optimizer for every PDF structure.
• Long or high-resolution scanned files can require substantial memory and processing time.

Common errors and fixes

The file did not get smaller.

The PDF may already be optimized or mostly text/vector content; try scanned mode only if rasterization is acceptable.

Text is no longer selectable.

Use Safe re-save instead of scanned/image-heavy mode.

Small text looks soft.

Increase raster scale or quality, or return to Safe re-save.

Compress PDF FAQ